version bump (#1477)

* random permutation

* comment

.circleci/config.yml

@@ -31,19 +31,24 @@ jobs:
           name: Install dependencies
           command: |
             pip install --upgrade cmake
-            pip install git+https://github.com/wjakob/nanobind.git@2f04eac452a6d9142dedb957701bdb20125561e4
+            pip install nanobind==2.2.0
             pip install numpy
             sudo apt-get update
             sudo apt-get install libblas-dev liblapack-dev liblapacke-dev
       - run:
           name: Install Python package
           command: |
-            CMAKE_ARGS="-DMLX_BUILD_METAL=OFF" CMAKE_BUILD_PARALLEL_LEVEL="" python3 setup.py build_ext --inplace
-            CMAKE_ARGS="-DMLX_BUILD_METAL=OFF" CMAKE_BUILD_PARALLEL_LEVEL="" python3 setup.py develop
+            CMAKE_ARGS="-DMLX_BUILD_METAL=OFF" \
+              CMAKE_BUILD_PARALLEL_LEVEL=`nproc` \
+              python3 setup.py build_ext --inplace
+            CMAKE_ARGS="-DMLX_BUILD_METAL=OFF" \
+              CMAKE_BUILD_PARALLEL_LEVEL=`nproc` \
+              python3 setup.py develop
       - run:
           name: Generate package stubs
           command: |
             echo "stubs"
+            pip install typing_extensions
             python setup.py generate_stubs 
       - run:
           name: Run Python tests
@@ -52,7 +57,9 @@ jobs:
       - run:
           name: Build CPP only
           command: |
-            mkdir -p build && cd build && cmake .. -DMLX_BUILD_METAL=OFF && make -j
+            mkdir -p build && cd build 
+            cmake .. -DMLX_BUILD_METAL=OFF -DCMAKE_BUILD_TYPE=DEBUG
+            make -j `nproc`
       - run:
           name: Run CPP tests
           command: ./build/tests/tests
@@ -76,7 +83,7 @@ jobs:
             source env/bin/activate
             pip install --upgrade pip
             pip install --upgrade cmake
-            pip install git+https://github.com/wjakob/nanobind.git@2f04eac452a6d9142dedb957701bdb20125561e4
+            pip install nanobind==2.2.0
             pip install numpy
             pip install torch
             pip install tensorflow
@@ -85,11 +92,12 @@ jobs:
           name: Install Python package
           command: |
             source env/bin/activate
-            CMAKE_BUILD_PARALLEL_LEVEL="" pip install -e . -v
+            DEBUG=1 CMAKE_BUILD_PARALLEL_LEVEL=`sysctl -n hw.ncpu` pip install -e . -v
       - run:
           name: Generate package stubs
           command: |
             source env/bin/activate
+            pip install typing_extensions
             python setup.py generate_stubs 
       - run:
           name: Run Python tests
@@ -97,7 +105,7 @@ jobs:
             source env/bin/activate
             LOW_MEMORY=1 DEVICE=cpu python -m xmlrunner discover -v python/tests -o test-results/cpu
             LOW_MEMORY=1 DEVICE=gpu METAL_DEVICE_WRAPPER_TYPE=1 METAL_DEBUG_ERROR_MODE=0 python -m xmlrunner discover -v python/tests -o test-results/gpu
-            mpirun -host localhost:8 -np 8 -x DYLD_LIBRARY_PATH=/opt/homebrew/lib/ python python/tests/mpi_test_distributed.py
+            mpirun --bind-to none -host localhost:8 -np 8 -x DYLD_LIBRARY_PATH=/opt/homebrew/lib/ python python/tests/mpi_test_distributed.py
       - run:
           name: Build example extension
           command: |
@@ -111,7 +119,7 @@ jobs:
           name: Build CPP only
           command: |
             source env/bin/activate
-            mkdir -p build && cd build && cmake .. && make -j
+            mkdir -p build && cd build && cmake .. && make -j `sysctl -n hw.ncpu`
       - run:
           name: Run CPP tests
           command: |
@@ -121,8 +129,23 @@ jobs:
           command: |
             source env/bin/activate
             cd build/
-            cmake .. -DCMAKE_BUILD_TYPE=MinSizeRel -DBUILD_SHARED_LIBS=ON -DMLX_BUILD_CPU=OFF -DMLX_BUILD_SAFETENSORS=OFF -DMLX_BUILD_GGUF=OFF -DMLX_METAL_JIT=ON
-            make -j
+            cmake .. -DCMAKE_BUILD_TYPE=MinSizeRel \
+              -DBUILD_SHARED_LIBS=ON \
+              -DMLX_BUILD_CPU=OFF \
+              -DMLX_BUILD_SAFETENSORS=OFF \
+              -DMLX_BUILD_GGUF=OFF \
+              -DMLX_METAL_JIT=ON
+            make -j `sysctl -n hw.ncpu`
+      - run:
+          name: Run Python tests with JIT
+          command: |
+            source env/bin/activate
+            CMAKE_BUILD_PARALLEL_LEVEL=`sysctl -n hw.ncpu` \
+              CMAKE_ARGS="-DMLX_METAL_JIT=ON" \
+              pip install -e . -v
+            LOW_MEMORY=1 DEVICE=gpu METAL_DEVICE_WRAPPER_TYPE=1 \
+              METAL_DEBUG_ERROR_MODE=0 \
+              python -m xmlrunner discover -v python/tests -o test-results/gpu_jit
 
   build_release:
     parameters:
@@ -144,11 +167,12 @@ jobs:
           name: Install dependencies
           command: |
             brew install python@<< parameters.python_version >>
+            brew install openmpi
             python<< parameters.python_version >> -m venv env
             source env/bin/activate
             pip install --upgrade pip
             pip install --upgrade cmake
-            pip install git+https://github.com/wjakob/nanobind.git@2f04eac452a6d9142dedb957701bdb20125561e4
+            pip install nanobind==2.2.0
             pip install --upgrade setuptools
             pip install numpy
             pip install twine
@@ -158,19 +182,20 @@ jobs:
           command: |
             source env/bin/activate
             DEV_RELEASE=1 \
-              CMAKE_BUILD_PARALLEL_LEVEL="" \
+              CMAKE_BUILD_PARALLEL_LEVEL=`sysctl -n hw.ncpu` \
               pip install . -v
       - run:
           name: Generate package stubs
           command: |
             source env/bin/activate
+            pip install typing_extensions
             python setup.py generate_stubs 
       - run:
           name: Build Python package
           command: |
             source env/bin/activate
             << parameters.build_env >> \
-              CMAKE_BUILD_PARALLEL_LEVEL="" \
+              CMAKE_BUILD_PARALLEL_LEVEL=`sysctl -n hw.ncpu` \
               python -m build -w
       - when:
           condition: << parameters.build_env >>
@@ -212,18 +237,19 @@ jobs:
             source env/bin/activate
             pip install --upgrade pip
             pip install --upgrade cmake
-            pip install git+https://github.com/wjakob/nanobind.git@2f04eac452a6d9142dedb957701bdb20125561e4
+            pip install nanobind==2.2.0
             pip install --upgrade setuptools
             pip install numpy
             pip install auditwheel
             pip install patchelf
             pip install build
             << parameters.extra_env >> \
-              CMAKE_BUILD_PARALLEL_LEVEL="" \
+              CMAKE_BUILD_PARALLEL_LEVEL=`nproc` \
               pip install . -v
+            pip install typing_extensions
             python setup.py generate_stubs 
             << parameters.extra_env >> \
-              CMAKE_BUILD_PARALLEL_LEVEL="" \
+              CMAKE_BUILD_PARALLEL_LEVEL=`nproc` \
               python -m build --wheel
             auditwheel show dist/*
             auditwheel repair dist/* --plat manylinux_2_31_x86_64
@@ -244,7 +270,7 @@ workflows:
       - mac_build_and_test:
           matrix:
             parameters:
-              xcode_version: ["15.0.0", "15.2.0"]
+              xcode_version: ["15.0.0", "15.2.0", "16.0.0"]
       - linux_build_and_test
 
   build_pypi_release:
@@ -279,7 +305,7 @@ workflows:
           requires: [ hold ]
           matrix:
             parameters:
-              xcode_version: ["15.0.0", "15.2.0"]
+              xcode_version: ["15.0.0", "15.2.0", "16.0.0"]
       - linux_build_and_test:
           requires: [ hold ]
   nightly_build:
@@ -303,7 +329,7 @@ workflows:
           matrix:
             parameters:
               python_version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
-              xcode_version: ["15.0.0", "15.2.0"]
+              xcode_version: ["15.0.0", "15.2.0", "16.0.0"]
               build_env: ["DEV_RELEASE=1"]
   linux_test_release:
     when:

.github/workflows/pull_request.yml

@@ -17,4 +17,4 @@ jobs:
           pip install pre-commit black isort clang-format
       - name: Run lint
         run: |
-          pre-commit run --all-files
+          pre-commit run --all-files

.pre-commit-config.yaml

@@ -1,11 +1,11 @@
 repos:
 -   repo: https://github.com/pre-commit/mirrors-clang-format
-    rev: v18.1.4
+    rev: v18.1.8
     hooks:
     -   id: clang-format
 # Using this mirror lets us use mypyc-compiled black, which is about 2x faster
 -   repo: https://github.com/psf/black-pre-commit-mirror
-    rev: 24.4.2
+    rev: 24.8.0
     hooks:
     -   id: black
 -   repo: https://github.com/pycqa/isort
@@ -14,3 +14,7 @@ repos:
     -   id: isort
         args:
             - --profile=black
+- repo: https://github.com/cheshirekow/cmake-format-precommit
+  rev: v0.6.13
+  hooks:
+    - id: cmake-format

ACKNOWLEDGMENTS.md

@@ -7,16 +7,18 @@ with a short description of your contribution(s) below. For example:
 
 MLX was developed with contributions from the following individuals:
 
-- Nripesh Niketan: Added `softsign`, `softmax`, `hardswish`, `logsoftmax` activation functions. Added `dropout3d` ops. Added `LogicalAnd` and `LogicalOR` ops. Added `clip_grad_norm` along with `tree_reduce`.
+- Nripesh Niketan: Added `softsign`, `softmax`, `hardswish`, `logsoftmax` activation functions. Added `dropout3d` ops. Added `LogicalAnd` and `LogicalOR` ops. Added `clip_grad_norm` along with `tree_reduce`. Added `cross`.
 - Juarez Bochi: Fixed bug in cross attention.
 - Justin Deschenaux: Sine, Cosine, arange, randint, truncated normal, bernoulli, lion optimizer, Dropout2d, linear and logistic regression python example.
-- Diogo Da Cruz: Added `tri`, `tril`, `triu`, `tensordot`, `inner`, `outer`, `tile`, `StreamContext`, `stream` and safetensor support.
+- Diogo Da Cruz: Added `tri`, `tril`, `triu`, `tensordot`, `inner`, `outer`, `tile`, `StreamContext`, `stream`, safetensors support, `einsum`, and `einsum_path`.
 - Gabrijel Boduljak: Added `mlx.core.linalg`, implemented `norm` method and `InstanceNorm` layer. Implemented pooling layers and ``Upsample``.
 - Hinrik Snær Guðmundsson: Added `atleast_1d`, `atleast_2d`, `atleast_3d` ops.
 - Luca Arnaboldi: Added `Ceil` and `Floor` ops; implemented pickling, copy and deepcopy for mlx arrays.
 - Brian Keene & Atila Orhon, with Argmax Inc.: Added `fast.scaled_dot_product_attention`
 - AmirHossein Razlighi: Added chaining support for some of the ops in `nn.Module`. Comparison works for non array objects in `mlx.core.array`. Exception handling for invalid operations in `mlx.core.array`.
 - Gleb Pobudzey: Added the `where` primitive, and groups in 1D and 2D convolutions.
+- Paul Paczuski: Improved stability of BCE loss calculation
+- Max-Heinrich Laves: Added `conv_transpose1d`, `conv_transpose2d`, and `conv_transpose3d` ops.
 
 <a href="https://github.com/ml-explore/mlx/graphs/contributors">
   <img class="dark-light" src="https://contrib.rocks/image?repo=ml-explore/mlx&anon=0&columns=20&max=100&r=true" />

CITATION.cff

@@ -0,0 +1,24 @@
+cff-version: 1.2.0
+title: mlx
+message: >-
+  If you use this software, please cite it using the
+  metadata from this file.
+type: software
+authors:
+  - given-names: Awni
+    family-names: Hannun
+    affiliation: Apple
+  - given-names: Jagrit
+    family-names: Digani
+    affiliation: Apple
+  - given-names: Angelos
+    family-names: Katharopoulos
+    affiliation: Apple
+  - given-names: Ronan
+    family-names: Collobert
+    affiliation: Apple
+repository-code: 'https://github.com/ml-explore'
+abstract: >-
+  MLX: efficient and flexible machine learning on Apple
+  silicon
+license: MIT

CMakeLists.txt

@@ -24,35 +24,43 @@ option(MLX_METAL_JIT "Use JIT compilation for Metal kernels" OFF)
 option(BUILD_SHARED_LIBS "Build mlx as a shared library" OFF)
 
 if(NOT MLX_VERSION)
-  set(MLX_VERSION 0.15.0)
+  set(MLX_VERSION 0.18.1)
 endif()
 
 # --------------------- Processor tests -------------------------
 
-message(STATUS "Building MLX for ${CMAKE_SYSTEM_PROCESSOR} processor on ${CMAKE_SYSTEM_NAME}")
+message(
+  STATUS
+    "Building MLX for ${CMAKE_SYSTEM_PROCESSOR} processor on ${CMAKE_SYSTEM_NAME}"
+)
 
 set(MLX_BUILD_ARM OFF)
 
-if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
   if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "x86_64")
     if(NOT MLX_ENABLE_X64_MAC)
-      message(FATAL_ERROR
-        "Building for x86_64 on macOS is not supported."
-        " If you are on an Apple silicon system, check the build"
-        " documentation for possible fixes: "
-        "https://ml-explore.github.io/mlx/build/html/install.html#build-from-source")
+      message(
+        FATAL_ERROR
+          "Building for x86_64 on macOS is not supported."
+          " If you are on an Apple silicon system, check the build"
+          " documentation for possible fixes: "
+          "https://ml-explore.github.io/mlx/build/html/install.html#build-from-source"
+      )
     else()
+      set(MLX_BUILD_METAL OFF)
       message(WARNING "Building for x86_64 arch is not officially supported.")
     endif()
-    set(MLX_BUILD_METAL OFF)
-  elseif(${CMAKE_SYSTEM_PROCESSOR} MATCHES "arm64")
-    set(MLX_BUILD_ARM ON)
   endif()
 
 else()
+  set(MLX_BUILD_METAL OFF)
   message(WARNING "MLX is prioritised for Apple silicon systems using macOS.")
 endif()
 
+if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "arm64")
+  set(MLX_BUILD_ARM ON)
+endif()
+
 # ----------------------------- Lib -----------------------------
 
 include(FetchContent)
@@ -61,66 +69,59 @@ cmake_policy(SET CMP0135 NEW)
 
 add_library(mlx)
 
-if (MLX_BUILD_METAL)
-  find_library(METAL_LIB Metal)
-  find_library(FOUNDATION_LIB Foundation)
-  find_library(QUARTZ_LIB QuartzCore)
+if(MLX_BUILD_METAL)
+  set(METAL_LIB "-framework Metal")
+  set(FOUNDATION_LIB "-framework Foundation")
+  set(QUARTZ_LIB "-framework QuartzCore")
 endif()
 
-if (MLX_BUILD_METAL AND NOT METAL_LIB)
+if(MLX_BUILD_METAL AND NOT METAL_LIB)
   message(STATUS "Metal not found. Unable to build GPU")
   set(MLX_BUILD_METAL OFF)
   set(MLX_METAL_DEBUG OFF)
-elseif (MLX_BUILD_METAL)
+elseif(MLX_BUILD_METAL)
   message(STATUS "Building METAL sources")
 
-  if (MLX_METAL_DEBUG)
+  if(MLX_METAL_DEBUG)
     add_compile_definitions(MLX_METAL_DEBUG)
   endif()
 
   # Throw an error if xcrun not found
-  execute_process(COMMAND zsh "-c" "/usr/bin/xcrun -sdk macosx --show-sdk-version"
-                  OUTPUT_VARIABLE MACOS_VERSION
-                  COMMAND_ERROR_IS_FATAL ANY)
+  execute_process(
+    COMMAND zsh "-c" "/usr/bin/xcrun -sdk macosx --show-sdk-version"
+    OUTPUT_VARIABLE MACOS_VERSION COMMAND_ERROR_IS_FATAL ANY)
 
+  if(${MACOS_VERSION} LESS 14.0)
+    message(
+      FATAL_ERROR
+        "MLX requires macOS SDK >= 14.0 to be built with MLX_BUILD_METAL=ON")
+  endif()
   message(STATUS "Building with SDK for macOS version ${MACOS_VERSION}")
 
-  if (${MACOS_VERSION} GREATER_EQUAL 14.2)
-    set(METAL_CPP_PATCH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/metal.14.2.diff)
-    set(METAL_CPP_URL https://developer.apple.com/metal/cpp/files/metal-cpp_macOS14.2_iOS17.2.zip)
-    set(MLX_METAL_VERSION METAL_3_1)
-  elseif (${MACOS_VERSION} GREATER_EQUAL 14.0)
-    set(METAL_CPP_PATCH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/metal.14.0.diff)
-    set(METAL_CPP_URL https://developer.apple.com/metal/cpp/files/metal-cpp_macOS14_iOS17-beta.zip)
-    set(MLX_METAL_VERSION METAL_3_0)
-  else()
-    message(FATAL_ERROR "MLX requires macOS SDK >= 14.0 to be built with MLX_BUILD_METAL=ON" )
-  endif()
-
-  FetchContent_Declare(
-    metal_cpp
-    URL ${METAL_CPP_URL}
-    PATCH_COMMAND /usr/bin/patch -N -i ${METAL_CPP_PATCH} || true
+  set(METAL_CPP_URL
+      https://developer.apple.com/metal/cpp/files/metal-cpp_macOS15_iOS18-beta.zip
   )
+  # Get the metal version
+  execute_process(
+    COMMAND
+      zsh "-c"
+      "echo \"__METAL_VERSION__\" | xcrun -sdk macosx metal -E -x metal -P - | tail -1 | tr -d '\n'"
+    OUTPUT_VARIABLE MLX_METAL_VERSION COMMAND_ERROR_IS_FATAL ANY)
+
+  FetchContent_Declare(metal_cpp URL ${METAL_CPP_URL})
 
   FetchContent_MakeAvailable(metal_cpp)
   target_include_directories(
-    mlx PUBLIC
-    $<BUILD_INTERFACE:${metal_cpp_SOURCE_DIR}>
-    $<INSTALL_INTERFACE:include/metal_cpp>
-  )
-  target_link_libraries(
-    mlx PUBLIC
-    ${METAL_LIB}
-    ${FOUNDATION_LIB}
-    ${QUARTZ_LIB})
+    mlx PUBLIC $<BUILD_INTERFACE:${metal_cpp_SOURCE_DIR}>
+               $<INSTALL_INTERFACE:include/metal_cpp>)
+  target_link_libraries(mlx PUBLIC ${METAL_LIB} ${FOUNDATION_LIB} ${QUARTZ_LIB})
 
-  add_compile_definitions(${MLX_METAL_VERSION})
+  add_compile_definitions("MLX_METAL_VERSION=${MLX_METAL_VERSION}")
 endif()
 
-if (MLX_BUILD_CPU)
+if(MLX_BUILD_CPU)
   find_library(ACCELERATE_LIBRARY Accelerate)
-  if (MLX_BUILD_ARM AND ACCELERATE_LIBRARY)
+  if(MLX_BUILD_ARM AND ACCELERATE_LIBRARY)
     message(STATUS "Accelerate found ${ACCELERATE_LIBRARY}")
     set(MLX_BUILD_ACCELERATE ON)
     target_link_libraries(mlx PUBLIC ${ACCELERATE_LIBRARY})
@@ -132,32 +133,29 @@ if (MLX_BUILD_CPU)
       # The blas shipped in macOS SDK is not supported, search homebrew for
       # openblas instead.
       set(BLA_VENDOR OpenBLAS)
-      set(LAPACK_ROOT "${LAPACK_ROOT};$ENV{LAPACK_ROOT};/usr/local/opt/openblas")
+      set(LAPACK_ROOT
+          "${LAPACK_ROOT};$ENV{LAPACK_ROOT};/usr/local/opt/openblas")
     endif()
     # Search and link with lapack.
     find_package(LAPACK REQUIRED)
-    if (NOT LAPACK_FOUND)
+    if(NOT LAPACK_FOUND)
       message(FATAL_ERROR "Must have LAPACK installed")
     endif()
-    find_path(LAPACK_INCLUDE_DIRS lapacke.h
-      /usr/include
-      /usr/local/include
-      /usr/local/opt/openblas/include)
+    find_path(LAPACK_INCLUDE_DIRS lapacke.h /usr/include /usr/local/include
+              /usr/local/opt/openblas/include)
     message(STATUS "Lapack lib " ${LAPACK_LIBRARIES})
     message(STATUS "Lapack include " ${LAPACK_INCLUDE_DIRS})
     target_include_directories(mlx PRIVATE ${LAPACK_INCLUDE_DIRS})
     target_link_libraries(mlx PUBLIC ${LAPACK_LIBRARIES})
-    # List blas after lapack otherwise we may accidentally incldue an old version
-    # of lapack.h from the include dirs of blas.
+    # List blas after lapack otherwise we may accidentally incldue an old
+    # version of lapack.h from the include dirs of blas.
     find_package(BLAS REQUIRED)
-    if (NOT BLAS_FOUND)
+    if(NOT BLAS_FOUND)
       message(FATAL_ERROR "Must have BLAS installed")
     endif()
     # TODO find a cleaner way to do this
-    find_path(BLAS_INCLUDE_DIRS cblas.h
-      /usr/include
-      /usr/local/include
-      $ENV{BLAS_HOME}/include)
+    find_path(BLAS_INCLUDE_DIRS cblas.h /usr/include /usr/local/include
+              $ENV{BLAS_HOME}/include)
     message(STATUS "Blas lib " ${BLAS_LIBRARIES})
     message(STATUS "Blas include " ${BLAS_INCLUDE_DIRS})
     target_include_directories(mlx PRIVATE ${BLAS_INCLUDE_DIRS})
@@ -168,84 +166,95 @@ else()
 endif()
 
 find_package(MPI)
-if (MPI_FOUND)
+if(MPI_FOUND)
+  execute_process(
+    COMMAND zsh "-c" "mpirun --version"
+    OUTPUT_VARIABLE MPI_VERSION
+    ERROR_QUIET)
+  if(${MPI_VERSION} MATCHES ".*Open MPI.*")
     target_include_directories(mlx PRIVATE ${MPI_INCLUDE_PATH})
+  elseif(MPI_VERSION STREQUAL "")
+    set(MPI_FOUND FALSE)
+    message(
+      WARNING "MPI found but mpirun is not available. Building without MPI.")
+  else()
+    set(MPI_FOUND FALSE)
+    message(WARNING "MPI which is not OpenMPI found. Building without MPI.")
+  endif()
 endif()
 
 add_subdirectory(${CMAKE_CURRENT_LIST_DIR}/mlx)
 
 target_include_directories(
-  mlx
-  PUBLIC
-  $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}>
-  $<INSTALL_INTERFACE:include>
-)
+  mlx PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}>
+             $<INSTALL_INTERFACE:include>)
 
-FetchContent_Declare(fmt
+FetchContent_Declare(
+  fmt
   GIT_REPOSITORY https://github.com/fmtlib/fmt.git
-  GIT_TAG 10.2.1 
-  EXCLUDE_FROM_ALL
-)
+  GIT_TAG 10.2.1
+  EXCLUDE_FROM_ALL)
 FetchContent_MakeAvailable(fmt)
-target_link_libraries(mlx PRIVATE fmt::fmt-header-only)
+target_link_libraries(mlx PRIVATE $<BUILD_INTERFACE:fmt::fmt-header-only>)
 
-if (MLX_BUILD_PYTHON_BINDINGS)
+if(MLX_BUILD_PYTHON_BINDINGS)
   message(STATUS "Building Python bindings.")
-  find_package(Python 3.8 COMPONENTS Interpreter Development.Module REQUIRED)
+  find_package(
+    Python 3.8
+    COMPONENTS Interpreter Development.Module
+    REQUIRED)
   execute_process(
     COMMAND "${Python_EXECUTABLE}" -m nanobind --cmake_dir
-    OUTPUT_STRIP_TRAILING_WHITESPACE OUTPUT_VARIABLE NB_DIR)
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+    OUTPUT_VARIABLE NB_DIR)
   list(APPEND CMAKE_PREFIX_PATH "${NB_DIR}")
   find_package(nanobind CONFIG REQUIRED)
   add_subdirectory(${CMAKE_CURRENT_LIST_DIR}/python/src)
 endif()
 
-if (MLX_BUILD_TESTS)
+if(MLX_BUILD_TESTS)
   include(CTest)
   add_subdirectory(${CMAKE_CURRENT_LIST_DIR}/tests)
 endif()
 
-if (MLX_BUILD_EXAMPLES)
+if(MLX_BUILD_EXAMPLES)
   add_subdirectory(${CMAKE_CURRENT_LIST_DIR}/examples/cpp)
 endif()
 
-if (MLX_BUILD_BENCHMARKS)
+if(MLX_BUILD_BENCHMARKS)
   add_subdirectory(${CMAKE_CURRENT_LIST_DIR}/benchmarks/cpp)
 endif()
 
-
-
 # ----------------------------- Installation -----------------------------
 include(GNUInstallDirs)
 
 # Install library
 install(
-    TARGETS mlx
-    EXPORT MLXTargets
-    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
-    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
-    INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
-)
-
+  TARGETS mlx
+  EXPORT MLXTargets
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+  INCLUDES
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 
 # Install headers
 install(
-    DIRECTORY ${CMAKE_CURRENT_LIST_DIR}/mlx
-    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
-    COMPONENT headers
-    FILES_MATCHING PATTERN "*.h"
-)
+  DIRECTORY ${CMAKE_CURRENT_LIST_DIR}/mlx
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+  COMPONENT headers
+  FILES_MATCHING
+  PATTERN "*.h"
+  PATTERN "backend/metal/kernels.h" EXCLUDE)
 
 # Install metal dependencies
-if (MLX_BUILD_METAL)
+if(MLX_BUILD_METAL)
 
   # Install metal cpp
   install(
-      DIRECTORY ${metal_cpp_SOURCE_DIR}/
-      DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/metal_cpp
-      COMPONENT metal_cpp_source
-  )
+    DIRECTORY ${metal_cpp_SOURCE_DIR}/
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/metal_cpp
+    COMPONENT metal_cpp_source)
 
 endif()
 
@@ -257,31 +266,24 @@ set(MLX_CMAKE_INSTALL_MODULE_DIR share/cmake/MLX)
 install(
   EXPORT MLXTargets
   FILE MLXTargets.cmake
-  DESTINATION ${MLX_CMAKE_INSTALL_MODULE_DIR}
-)
+  DESTINATION ${MLX_CMAKE_INSTALL_MODULE_DIR})
 
 include(CMakePackageConfigHelpers)
 
 write_basic_package_version_file(
   ${MLX_CMAKE_BUILD_VERSION_CONFIG}
   COMPATIBILITY SameMajorVersion
-  VERSION ${MLX_VERSION}
-)
+  VERSION ${MLX_VERSION})
 
 configure_package_config_file(
-  ${CMAKE_CURRENT_LIST_DIR}/mlx.pc.in
-  ${MLX_CMAKE_BUILD_CONFIG}
+  ${CMAKE_CURRENT_LIST_DIR}/mlx.pc.in ${MLX_CMAKE_BUILD_CONFIG}
   INSTALL_DESTINATION ${MLX_CMAKE_INSTALL_MODULE_DIR}
   NO_CHECK_REQUIRED_COMPONENTS_MACRO
-  PATH_VARS CMAKE_INSTALL_LIBDIR CMAKE_INSTALL_INCLUDEDIR MLX_CMAKE_INSTALL_MODULE_DIR
-)
+  PATH_VARS CMAKE_INSTALL_LIBDIR CMAKE_INSTALL_INCLUDEDIR
+            MLX_CMAKE_INSTALL_MODULE_DIR)
 
-install(
-  FILES ${MLX_CMAKE_BUILD_CONFIG} ${MLX_CMAKE_BUILD_VERSION_CONFIG}
-  DESTINATION ${MLX_CMAKE_INSTALL_MODULE_DIR}
-)
+install(FILES ${MLX_CMAKE_BUILD_CONFIG} ${MLX_CMAKE_BUILD_VERSION_CONFIG}
+        DESTINATION ${MLX_CMAKE_INSTALL_MODULE_DIR})
 
-install(
-  DIRECTORY ${CMAKE_MODULE_PATH}/
-  DESTINATION ${MLX_CMAKE_INSTALL_MODULE_DIR}
-)
+install(DIRECTORY ${CMAKE_MODULE_PATH}/
+        DESTINATION ${MLX_CMAKE_INSTALL_MODULE_DIR})

benchmarks/python/conv2d_bench_cpu.py

@@ -0,0 +1,127 @@
+import argparse
+import math
+import time
+
+import mlx.core as mx
+import numpy as np
+import torch
+
+N_warmup = 1
+N_iter_bench = 10
+N_iter_func = 5
+mx.set_default_device(mx.cpu)
+
+
+def bench(f, a, b):
+    for i in range(N_warmup):
+        f(a, b)
+
+    s = time.perf_counter_ns()
+    for i in range(N_iter_bench):
+        f(a, b)
+    e = time.perf_counter_ns()
+    return (e - s) * 1e-9
+
+
+def make_mx_conv_2D(strides=(1, 1), padding=(0, 0), groups=1):
+    def mx_conv_2D(a, b):
+        ys = []
+        for i in range(N_iter_func):
+            y = mx.conv2d(a, b, stride=strides, padding=padding, groups=groups)
+            ys.append(y)
+        mx.eval(ys)
+        return ys
+
+    return mx_conv_2D
+
+
+def make_pt_conv_2D(strides=(1, 1), padding=(0, 0), groups=1):
+    @torch.no_grad()
+    def pt_conv_2D(a, b):
+        ys = []
+        for i in range(N_iter_func):
+            y = torch.conv2d(a, b, stride=strides, padding=padding, groups=groups)
+            ys.append(y)
+        return ys
+
+    return pt_conv_2D
+
+
+def bench_shape(N, H, W, C, kH, kW, O, strides, padding, groups, np_dtype):
+    scale = 1.0 / math.sqrt(kH * kH * C)
+    a_np = np.random.uniform(0, 0.5, (N, H, W, C)).astype(np_dtype)
+    b_np = np.random.uniform(-scale, scale, (O, kH, kW, int(C / groups))).astype(
+        np_dtype
+    )
+
+    a_mx = mx.array(a_np)
+    b_mx = mx.array(b_np)
+
+    a_pt = torch.from_numpy(a_np.transpose((0, 3, 1, 2))).to("cpu")
+    b_pt = torch.from_numpy(b_np.transpose((0, 3, 1, 2))).to("cpu")
+
+    f_mx = make_mx_conv_2D(strides, padding, groups)
+    f_pt = make_pt_conv_2D(strides, padding, groups)
+
+    time_torch = bench(f_pt, a_pt, b_pt)
+    time_mlx = bench(f_mx, a_mx, b_mx)
+
+    out_mx = mx.conv2d(a_mx, b_mx, stride=strides, padding=padding, groups=groups)
+    out_pt = torch.conv2d(
+        a_pt.to("cpu"), b_pt.to("cpu"), stride=strides, padding=padding, groups=groups
+    )
+    out_pt = torch.permute(out_pt, (0, 2, 3, 1))
+    out_pt = out_pt.numpy(force=True)
+
+    atol = 2e-5 if np_dtype == np.float32 else 1e-4
+
+    if not np.allclose(out_pt, out_mx, atol=atol):
+        print(
+            f"Failed at {(N, H, W, C)}, {(O, kH, kW, C)} [strides = {strides}, padding = {padding}, groups = {groups}] with max(|a - b|) = {np.max(np.abs(out_pt - out_mx))}"
+        )
+
+    return time_mlx, time_torch
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="Run conv benchmarks")
+
+    dtypes = ("float32",)
+    shapes = (
+        (4, 32, 32, 32, 5, 5, 32, (1, 1), (2, 2), 1),
+        (4, 32, 32, 64, 5, 5, 64, (1, 1), (2, 2), 1),
+        (4, 32, 32, 128, 5, 5, 128, (1, 1), (2, 2), 1),
+        (4, 32, 32, 256, 5, 5, 256, (1, 1), (2, 2), 1),
+        (4, 32, 32, 512, 5, 5, 512, (1, 1), (2, 2), 1),
+        (4, 64, 64, 32, 5, 5, 32, (1, 1), (2, 2), 1),
+        (4, 64, 64, 64, 5, 5, 64, (1, 1), (2, 2), 1),
+        (4, 64, 64, 128, 5, 5, 128, (1, 1), (2, 2), 1),
+        (4, 64, 64, 256, 5, 5, 256, (1, 1), (2, 2), 1),
+        # (4, 64, 64, 256, 5, 5, 256, (1, 1), (2, 2), 2),
+        # (4, 64, 64, 256, 5, 5, 256, (1, 1), (2, 2), 16),
+        # (4, 64, 64, 256, 5, 5, 256, (1, 1), (2, 2), 64),
+        (4, 128, 128, 32, 5, 5, 32, (1, 1), (2, 2), 1),
+        (4, 128, 128, 64, 5, 5, 64, (1, 1), (2, 2), 1),
+        (4, 128, 128, 128, 5, 5, 128, (1, 1), (2, 2), 1),
+        (4, 256, 256, 32, 5, 5, 3, (1, 1), (2, 2), 1),
+        (4, 256, 256, 3, 5, 5, 32, (1, 1), (2, 2), 1),
+        (4, 128, 128, 64, 5, 5, 3, (1, 1), (2, 2), 1),
+        (4, 128, 128, 3, 5, 5, 64, (1, 1), (2, 2), 1),
+    )
+
+    for dtype in dtypes:
+        print(
+            "(N,   H,   W,   C), (  O, kH, kW,   C),   dtype, stride,   pads,  groups, diff%"
+        )
+        for N, H, W, C, kH, kW, O, strides, padding, groups in shapes:
+            np_dtype = getattr(np, dtype)
+            time_mlx, time_torch = bench_shape(
+                N, H, W, C, kH, kW, O, strides, padding, groups, np_dtype
+            )
+            diff = time_torch / time_mlx - 1.0
+
+            print(
+                f"({N}, {H:3d}, {W:3d}, {C:3d}), ({O:3d}, {kH:2d}, {kW:2d}, {C:3d}), {dtype}, {strides}, {padding}, {groups:7d}, {100. * diff:+5.2f}%"
+            )
+            if time_mlx >= 2.0 * time_torch:
+                print("ATTENTION ^^^^^^^")

benchmarks/python/conv2d_train_bench_cpu.py

@@ -0,0 +1,143 @@
+import time
+
+import mlx.core as mx
+import mlx.nn
+import mlx.optimizers as opt
+import torch
+
+
+def bench_mlx(steps: int = 20) -> float:
+    mx.set_default_device(mx.cpu)
+
+    class BenchNetMLX(mlx.nn.Module):
+        # simple encoder-decoder net
+
+        def __init__(self, in_channels, hidden_channels=32):
+            super().__init__()
+
+            self.net = mlx.nn.Sequential(
+                mlx.nn.Conv2d(in_channels, hidden_channels, kernel_size=3, padding=1),
+                mlx.nn.ReLU(),
+                mlx.nn.Conv2d(
+                    hidden_channels, 2 * hidden_channels, kernel_size=3, padding=1
+                ),
+                mlx.nn.ReLU(),
+                mlx.nn.ConvTranspose2d(
+                    2 * hidden_channels, hidden_channels, kernel_size=3, padding=1
+                ),
+                mlx.nn.ReLU(),
+                mlx.nn.ConvTranspose2d(
+                    hidden_channels, in_channels, kernel_size=3, padding=1
+                ),
+            )
+
+        def __call__(self, input):
+            return self.net(input)
+
+    benchNet = BenchNetMLX(3)
+    mx.eval(benchNet.parameters())
+    optim = opt.Adam(learning_rate=1e-3)
+
+    inputs = mx.random.normal([10, 256, 256, 3])
+
+    params = benchNet.parameters()
+    optim.init(params)
+
+    state = [benchNet.state, optim.state]
+
+    def loss_fn(params, image):
+        benchNet.update(params)
+        pred_image = benchNet(image)
+        return (pred_image - image).abs().mean()
+
+    def step(params, image):
+        loss, grads = mx.value_and_grad(loss_fn)(params, image)
+        optim.update(benchNet, grads)
+        return loss
+
+    total_time = 0.0
+    print("MLX:")
+    for i in range(steps):
+        start_time = time.perf_counter()
+
+        step(benchNet.parameters(), inputs)
+        mx.eval(state)
+        end_time = time.perf_counter()
+
+        print(f"{i:3d}, time={(end_time-start_time) * 1000:7.2f} ms")
+        total_time += (end_time - start_time) * 1000
+
+    return total_time
+
+
+def bench_torch(steps: int = 20) -> float:
+    device = torch.device("cpu")
+
+    class BenchNetTorch(torch.nn.Module):
+        # simple encoder-decoder net
+
+        def __init__(self, in_channels, hidden_channels=32):
+            super().__init__()
+
+            self.net = torch.nn.Sequential(
+                torch.nn.Conv2d(in_channels, hidden_channels, kernel_size=3, padding=1),
+                torch.nn.ReLU(),
+                torch.nn.Conv2d(
+                    hidden_channels, 2 * hidden_channels, kernel_size=3, padding=1
+                ),
+                torch.nn.ReLU(),
+                torch.nn.ConvTranspose2d(
+                    2 * hidden_channels, hidden_channels, kernel_size=3, padding=1
+                ),
+                torch.nn.ReLU(),
+                torch.nn.ConvTranspose2d(
+                    hidden_channels, in_channels, kernel_size=3, padding=1
+                ),
+            )
+
+        def forward(self, input):
+            return self.net(input)
+
+    benchNet = BenchNetTorch(3).to(device)
+    optim = torch.optim.Adam(benchNet.parameters(), lr=1e-3)
+
+    inputs = torch.randn(10, 3, 256, 256, device=device)
+
+    def loss_fn(pred_image, image):
+        return (pred_image - image).abs().mean()
+
+    total_time = 0.0
+    print("PyTorch:")
+    for i in range(steps):
+        start_time = time.perf_counter()
+
+        optim.zero_grad()
+        pred_image = benchNet(inputs)
+        loss = loss_fn(pred_image, inputs)
+        loss.backward()
+        optim.step()
+
+        end_time = time.perf_counter()
+
+        print(f"{i:3d}, time={(end_time-start_time) * 1000:7.2f} ms")
+        total_time += (end_time - start_time) * 1000
+
+    return total_time
+
+
+def main():
+    steps = 20
+    time_mlx = bench_mlx(steps)
+    time_torch = bench_torch(steps)
+
+    print(f"average time of MLX:     {time_mlx/steps:9.2f} ms")
+    print(f"total time of MLX:       {time_mlx:9.2f} ms")
+    print(f"average time of PyTorch: {time_torch/steps:9.2f} ms")
+    print(f"total time of PyTorch:   {time_torch:9.2f} ms")
+
+    diff = time_torch / time_mlx - 1.0
+    print(f"torch/mlx diff: {100. * diff:+5.2f}%")
+
+
+if __name__ == "__main__":
+    main()

benchmarks/python/conv2d_transpose_bench_cpu.py

@@ -0,0 +1,129 @@
+import argparse
+import math
+import time
+
+import mlx.core as mx
+import numpy as np
+import torch
+
+N_warmup = 1
+N_iter_bench = 10
+N_iter_func = 5
+
+
+def bench(f, a, b):
+    for i in range(N_warmup):
+        f(a, b)
+
+    s = time.perf_counter_ns()
+    for i in range(N_iter_bench):
+        f(a, b)
+    e = time.perf_counter_ns()
+    return (e - s) * 1e-9
+
+
+def make_mx_conv_transpose_2D(strides=(1, 1), padding=(0, 0), groups=1):
+    def mx_conv_transpose_2D(a, b):
+        ys = []
+        for i in range(N_iter_func):
+            y = mx.conv_transpose2d(
+                a, b, stride=strides, padding=padding, groups=groups, stream=mx.cpu
+            )
+            ys.append(y)
+        mx.eval(ys)
+        return ys
+
+    return mx_conv_transpose_2D
+
+
+def make_pt_conv_transpose_2D(strides=(1, 1), padding=(0, 0), groups=1):
+    @torch.no_grad()
+    def pt_conv_transpose_2D(a, b):
+        ys = []
+        for i in range(N_iter_func):
+            y = torch.conv_transpose2d(
+                a, b, stride=strides, padding=padding, groups=groups
+            )
+            ys.append(y)
+        return ys
+
+    return pt_conv_transpose_2D
+
+
+def bench_shape(N, H, W, C, kH, kW, O, strides, padding, groups, np_dtype):
+    scale = 1.0 / math.sqrt(kH * kH * C)
+    a_np = np.random.uniform(0, 0.5, (N, H, W, C)).astype(np_dtype)
+    b_np = np.random.uniform(-scale, scale, (int(O / groups), kH, kW, C)).astype(
+        np_dtype
+    )
+
+    a_mx = mx.array(a_np)
+    b_mx = mx.array(b_np)
+
+    a_pt = torch.from_numpy(a_np.transpose((0, 3, 1, 2))).to("cpu")
+    b_pt = torch.from_numpy(b_np.transpose((3, 0, 1, 2))).to("cpu")
+
+    f_mx = make_mx_conv_transpose_2D(strides, padding, groups)
+    f_pt = make_pt_conv_transpose_2D(strides, padding, groups)
+
+    time_torch = bench(f_pt, a_pt, b_pt)
+    time_mlx = bench(f_mx, a_mx, b_mx)
+
+    out_mx = mx.conv_transpose2d(
+        a_mx, b_mx, stride=strides, padding=padding, groups=groups, stream=mx.cpu
+    )
+    out_pt = torch.conv_transpose2d(
+        a_pt.to("cpu"), b_pt.to("cpu"), stride=strides, padding=padding, groups=groups
+    )
+    out_pt = torch.permute(out_pt, (0, 2, 3, 1))
+    out_pt = out_pt.numpy(force=True)
+
+    atol = 2e-5 if np_dtype == np.float32 else 1e-4
+
+    if not np.allclose(out_pt, out_mx, atol=atol):
+        print(
+            f"Failed at {(N, H, W, C)}, {(O, kH, kW, C)} [strides = {strides}, padding = {padding}, groups = {groups}] with max(|a - b|) = {np.max(np.abs(out_pt - out_mx))}"
+        )
+
+    return time_mlx, time_torch
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="Run conv benchmarks")
+
+    dtypes = ("float32",)
+    shapes = (
+        (4, 32, 32, 32, 5, 5, 32, (1, 1), (2, 2), 1),
+        (4, 32, 32, 64, 5, 5, 64, (1, 1), (2, 2), 1),
+        (4, 32, 32, 128, 5, 5, 128, (1, 1), (2, 2), 1),
+        (4, 32, 32, 256, 5, 5, 256, (1, 1), (2, 2), 1),
+        (4, 32, 32, 512, 5, 5, 512, (1, 1), (2, 2), 1),
+        (4, 64, 64, 32, 5, 5, 32, (1, 1), (2, 2), 1),
+        (4, 64, 64, 64, 5, 5, 64, (1, 1), (2, 2), 1),
+        (4, 64, 64, 128, 5, 5, 128, (1, 1), (2, 2), 1),
+        (4, 64, 64, 256, 5, 5, 256, (1, 1), (2, 2), 1),
+        (4, 128, 128, 32, 5, 5, 32, (1, 1), (2, 2), 1),
+        (4, 128, 128, 64, 5, 5, 64, (1, 1), (2, 2), 1),
+        (4, 128, 128, 128, 5, 5, 128, (1, 1), (2, 2), 1),
+        (4, 256, 256, 32, 5, 5, 3, (1, 1), (2, 2), 1),
+        (4, 256, 256, 3, 5, 5, 32, (1, 1), (2, 2), 1),
+        (4, 128, 128, 64, 5, 5, 3, (1, 1), (2, 2), 1),
+        (4, 128, 128, 3, 5, 5, 64, (1, 1), (2, 2), 1),
+    )
+
+    for dtype in dtypes:
+        print(
+            "(N,   H,   W,   C), (  O, kH, kW,   C),   dtype, stride,   pads,  groups, diff%"
+        )
+        for N, H, W, C, kH, kW, O, strides, padding, groups in shapes:
+            np_dtype = getattr(np, dtype)
+            time_mlx, time_torch = bench_shape(
+                N, H, W, C, kH, kW, O, strides, padding, groups, np_dtype
+            )
+            diff = time_torch / time_mlx - 1.0
+
+            print(
+                f"({N}, {H:3d}, {W:3d}, {C:3d}), ({O:3d}, {kH:2d}, {kW:2d}, {C:3d}), {dtype}, {strides}, {padding}, {groups:7d}, {100. * diff:+5.2f}%"
+            )
+            if time_mlx >= 2.0 * time_torch:
+                print("ATTENTION ^^^^^^^")

benchmarks/python/conv3d_bench_cpu.py

@@ -0,0 +1,110 @@
+import argparse
+import math
+import time
+
+import mlx.core as mx
+import numpy as np
+import torch
+
+N_warmup = 1
+N_iter_bench = 10
+N_iter_func = 5
+mx.set_default_device(mx.cpu)
+
+
+def bench(f, a, b):
+    for i in range(N_warmup):
+        f(a, b)
+
+    s = time.perf_counter_ns()
+    for i in range(N_iter_bench):
+        f(a, b)
+    e = time.perf_counter_ns()
+    return (e - s) * 1e-9
+
+
+def make_mx_conv_3D(strides=(1, 1), padding=(0, 0), groups=1):
+    def mx_conv_3D(a, b):
+        ys = []
+        for i in range(N_iter_func):
+            y = mx.conv3d(a, b, stride=strides, padding=padding, groups=groups)
+            ys.append(y)
+        mx.eval(ys)
+        return ys
+
+    return mx_conv_3D
+
+
+def make_pt_conv_3D(strides=(1, 1), padding=(0, 0), groups=1):
+    @torch.no_grad()
+    def pt_conv_3D(a, b):
+        ys = []
+        for i in range(N_iter_func):
+            y = torch.conv3d(a, b, stride=strides, padding=padding, groups=groups)
+            ys.append(y)
+        return ys
+
+    return pt_conv_3D
+
+
+def bench_shape(N, D, H, W, C, kD, kH, kW, O, strides, padding, groups, np_dtype):
+    scale = 1.0 / math.sqrt(kD * kH * kW * C)
+    a_np = np.random.uniform(0, 0.5, (N, D, H, W, C)).astype(np_dtype)
+    b_np = np.random.uniform(-scale, scale, (O, kD, kH, kW, int(C / groups))).astype(
+        np_dtype
+    )
+
+    a_mx = mx.array(a_np)
+    b_mx = mx.array(b_np)
+
+    a_pt = torch.from_numpy(a_np.transpose((0, 4, 1, 2, 3))).to("cpu")
+    b_pt = torch.from_numpy(b_np.transpose((0, 4, 1, 2, 3))).to("cpu")
+
+    f_mx = make_mx_conv_3D(strides, padding, groups)
+    f_pt = make_pt_conv_3D(strides, padding, groups)
+
+    time_torch = bench(f_pt, a_pt, b_pt)
+    time_mlx = bench(f_mx, a_mx, b_mx)
+
+    out_mx = mx.conv3d(a_mx, b_mx, stride=strides, padding=padding, groups=groups)
+    out_pt = torch.conv3d(
+        a_pt.to("cpu"), b_pt.to("cpu"), stride=strides, padding=padding, groups=groups
+    )
+    out_pt = torch.permute(out_pt, (0, 2, 3, 4, 1))
+    out_pt = out_pt.numpy(force=True)
+
+    atol = 2e-5 if np_dtype == np.float32 else 1e-4
+
+    if not np.allclose(out_pt, out_mx, atol=atol):
+        print(
+            f"Failed at {(N, D, H, W, C)}, {(O, kD, kH, kW, C)} [strides = {strides}, padding = {padding}, groups = {groups}] with max(|a - b|) = {np.max(np.abs(out_pt - out_mx))}"
+        )
+
+    return time_mlx, time_torch
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="Run conv benchmarks")
+
+    dtypes = ("float32",)
+    shapes = (
+        (4, 16, 16, 16, 16, 5, 5, 5, 16, (1, 1, 1), (2, 2, 2), 1),
+        (4, 16, 16, 16, 32, 5, 5, 5, 32, (1, 1, 1), (2, 2, 2), 1),
+    )
+
+    for dtype in dtypes:
+        print(
+            "(N,   D,   H,   W,   C), (  O, kD, kH, kW,   C),   dtype,    stride,      pads,  groups, diff%"
+        )
+        for N, D, H, W, C, kD, kH, kW, O, strides, padding, groups in shapes:
+            np_dtype = getattr(np, dtype)
+            time_mlx, time_torch = bench_shape(
+                N, D, H, W, C, kD, kH, kW, O, strides, padding, groups, np_dtype
+            )
+            diff = time_torch / time_mlx - 1.0
+
+            print(
+                f"({N}, {D:3d}, {H:3d}, {W:3d}, {C:3d}), ({O:3d}, {kD:2d}, {kH:2d}, {kW:2d}, {C:3d}), {dtype}, {strides}, {padding}, {groups:7d}, {100. * diff:+5.2f}%"
+            )
+            if time_mlx >= 2.0 * time_torch:
+                print("ATTENTION ^^^^^^^")

benchmarks/python/conv3d_train_bench_cpu.py

@@ -0,0 +1,143 @@
+import time
+
+import mlx.core as mx
+import mlx.nn
+import mlx.optimizers as opt
+import torch
+
+
+def bench_mlx(steps: int = 20, shape=(10, 32, 32, 32, 3)) -> float:
+    mx.set_default_device(mx.cpu)
+
+    class BenchNetMLX(mlx.nn.Module):
+        # simple encoder-decoder net
+
+        def __init__(self, in_channels, hidden_channels=16):
+            super().__init__()
+
+            self.net = mlx.nn.Sequential(
+                mlx.nn.Conv3d(in_channels, hidden_channels, kernel_size=3, padding=1),
+                mlx.nn.ReLU(),
+                mlx.nn.Conv3d(
+                    hidden_channels, 2 * hidden_channels, kernel_size=3, padding=1
+                ),
+                mlx.nn.ReLU(),
+                mlx.nn.ConvTranspose3d(
+                    2 * hidden_channels, hidden_channels, kernel_size=3, padding=1
+                ),
+                mlx.nn.ReLU(),
+                mlx.nn.ConvTranspose3d(
+                    hidden_channels, in_channels, kernel_size=3, padding=1
+                ),
+            )
+
+        def __call__(self, input):
+            return self.net(input)
+
+    benchNet = BenchNetMLX(3)
+    mx.eval(benchNet.parameters())
+    optim = opt.Adam(learning_rate=1e-3)
+
+    inputs = mx.random.normal(shape)
+
+    params = benchNet.parameters()
+    optim.init(params)
+
+    state = [benchNet.state, optim.state]
+
+    def loss_fn(params, image):
+        benchNet.update(params)
+        pred_image = benchNet(image)
+        return (pred_image - image).abs().mean()
+
+    def step(params, image):
+        loss, grads = mx.value_and_grad(loss_fn)(params, image)
+        optim.update(benchNet, grads)
+        return loss
+
+    total_time = 0.0
+    print("MLX:")
+    for i in range(steps):
+        start_time = time.perf_counter()
+
+        step(benchNet.parameters(), inputs)
+        mx.eval(state)
+        end_time = time.perf_counter()
+
+        print(f"{i:3d}, time={(end_time-start_time) * 1000:7.2f} ms")
+        total_time += (end_time - start_time) * 1000
+
+    return total_time
+
+
+def bench_torch(steps: int = 20, shape=(10, 3, 32, 32, 32)) -> float:
+    device = torch.device("cpu")
+
+    class BenchNetTorch(torch.nn.Module):
+        # simple encoder-decoder net
+
+        def __init__(self, in_channels, hidden_channels=16):
+            super().__init__()
+
+            self.net = torch.nn.Sequential(
+                torch.nn.Conv3d(in_channels, hidden_channels, kernel_size=3, padding=1),
+                torch.nn.ReLU(),
+                torch.nn.Conv3d(
+                    hidden_channels, 2 * hidden_channels, kernel_size=3, padding=1
+                ),
+                torch.nn.ReLU(),
+                torch.nn.ConvTranspose3d(
+                    2 * hidden_channels, hidden_channels, kernel_size=3, padding=1
+                ),
+                torch.nn.ReLU(),
+                torch.nn.ConvTranspose3d(
+                    hidden_channels, in_channels, kernel_size=3, padding=1
+                ),
+            )
+
+        def forward(self, input):
+            return self.net(input)
+
+    benchNet = BenchNetTorch(3).to(device)
+    optim = torch.optim.Adam(benchNet.parameters(), lr=1e-3)
+
+    inputs = torch.randn(*shape, device=device)
+
+    def loss_fn(pred_image, image):
+        return (pred_image - image).abs().mean()
+
+    total_time = 0.0
+    print("PyTorch:")
+    for i in range(steps):
+        start_time = time.perf_counter()
+
+        optim.zero_grad()
+        pred_image = benchNet(inputs)
+        loss = loss_fn(pred_image, inputs)
+        loss.backward()
+        optim.step()
+
+        end_time = time.perf_counter()
+
+        print(f"{i:3d}, time={(end_time-start_time) * 1000:7.2f} ms")
+        total_time += (end_time - start_time) * 1000
+
+    return total_time
+
+
+def main():
+    steps = 10
+    time_mlx = bench_mlx(steps)
+    time_torch = bench_torch(steps)
+
+    print(f"average time of MLX:     {time_mlx/steps:9.2f} ms")
+    print(f"total time of MLX:       {time_mlx:9.2f} ms")
+    print(f"average time of PyTorch: {time_torch/steps:9.2f} ms")
+    print(f"total time of PyTorch:   {time_torch:9.2f} ms")
+
+    diff = time_torch / time_mlx - 1.0
+    print(f"torch/mlx diff: {100. * diff:+5.2f}%")
+
+
+if __name__ == "__main__":
+    main()

benchmarks/python/conv3d_transpose_bench_cpu.py

@@ -0,0 +1,116 @@
+import argparse
+import math
+import time
+
+import mlx.core as mx
+import numpy as np
+import torch
+
+N_warmup = 1
+N_iter_bench = 10
+N_iter_func = 5
+mx.set_default_device(mx.cpu)
+
+
+def bench(f, a, b):
+    for i in range(N_warmup):
+        f(a, b)
+
+    s = time.perf_counter_ns()
+    for i in range(N_iter_bench):
+        f(a, b)
+    e = time.perf_counter_ns()
+    return (e - s) * 1e-9
+
+
+def make_mx_conv_3D(strides=(1, 1, 1), padding=(0, 0, 0), groups=1):
+    def mx_conv_3D(a, b):
+        ys = []
+        for i in range(N_iter_func):
+            y = mx.conv_transpose3d(
+                a, b, stride=strides, padding=padding, groups=groups
+            )
+            ys.append(y)
+        mx.eval(ys)
+        return ys
+
+    return mx_conv_3D
+
+
+def make_pt_conv_3D(strides=(1, 1, 1), padding=(0, 0, 0), groups=1):
+    @torch.no_grad()
+    def pt_conv_3D(a, b):
+        ys = []
+        for i in range(N_iter_func):
+            y = torch.conv_transpose3d(
+                a, b, stride=strides, padding=padding, groups=groups
+            )
+            ys.append(y)
+        return ys
+
+    return pt_conv_3D
+
+
+def bench_shape(N, D, H, W, C, kD, kH, kW, O, strides, padding, groups, np_dtype):
+    scale = 1.0 / math.sqrt(kD * kH * kW * C)
+    a_np = np.random.uniform(0, 0.5, (N, D, H, W, C)).astype(np_dtype)
+    b_np = np.random.uniform(-scale, scale, (O, kD, kH, kW, int(C / groups))).astype(
+        np_dtype
+    )
+
+    a_mx = mx.array(a_np)
+    b_mx = mx.array(b_np)
+
+    a_pt = torch.from_numpy(a_np.transpose((0, 4, 1, 2, 3))).to("cpu")
+    b_pt = torch.from_numpy(b_np.transpose((4, 0, 1, 2, 3))).to("cpu")
+
+    f_mx = make_mx_conv_3D(strides, padding, groups)
+    f_pt = make_pt_conv_3D(strides, padding, groups)
+
+    time_torch = bench(f_pt, a_pt, b_pt)
+    time_mlx = bench(f_mx, a_mx, b_mx)
+
+    out_mx = mx.conv_transpose3d(
+        a_mx, b_mx, stride=strides, padding=padding, groups=groups
+    )
+    out_pt = torch.conv_transpose3d(
+        a_pt.to("cpu"), b_pt.to("cpu"), stride=strides, padding=padding, groups=groups
+    )
+    out_pt = torch.permute(out_pt, (0, 2, 3, 4, 1))
+    out_pt = out_pt.numpy(force=True)
+
+    atol = 2e-5 if np_dtype == np.float32 else 1e-4
+
+    if not np.allclose(out_pt, out_mx, atol=atol):
+        print(
+            f"Failed at {(N, D, H, W, C)}, {(O, kD, kH, kW, C)} [strides = {strides}, padding = {padding}, groups = {groups}] with max(|a - b|) = {np.max(np.abs(out_pt - out_mx))}"
+        )
+
+    return time_mlx, time_torch
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="Run conv benchmarks")
+
+    dtypes = ("float32",)
+    shapes = (
+        (4, 16, 16, 16, 16, 5, 5, 5, 16, (1, 1, 1), (2, 2, 2), 1),
+        (4, 16, 16, 16, 32, 5, 5, 5, 32, (1, 1, 1), (2, 2, 2), 1),
+    )
+
+    for dtype in dtypes:
+        print(
+            "(N,   D,   H,   W,   C), (  O, kD, kH, kW,   C),   dtype,    stride,      pads,  groups, diff%"
+        )
+        for N, D, H, W, C, kD, kH, kW, O, strides, padding, groups in shapes:
+            np_dtype = getattr(np, dtype)
+            time_mlx, time_torch = bench_shape(
+                N, D, H, W, C, kD, kH, kW, O, strides, padding, groups, np_dtype
+            )
+            diff = time_torch / time_mlx - 1.0
+
+            print(
+                f"({N}, {D:3d}, {H:3d}, {W:3d}, {C:3d}), ({O:3d}, {kD:2d}, {kH:2d}, {kW:2d}, {C:3d}), {dtype}, {strides}, {padding}, {groups:7d}, {100. * diff:+5.2f}%"
+            )
+            if time_mlx >= 2.0 * time_torch:
+                print("ATTENTION ^^^^^^^")

benchmarks/python/conv_transpose_bench.py

@@ -0,0 +1,135 @@
+import argparse
+import math
+import os
+import subprocess
+import time
+
+import mlx.core as mx
+import numpy as np
+import torch
+
+N_warmup = 10
+N_iter_bench = 100
+N_iter_func = 5
+
+
+def bench(f, a, b):
+    for i in range(N_warmup):
+        f(a, b)
+    torch.mps.synchronize()
+
+    s = time.perf_counter_ns()
+    for i in range(N_iter_bench):
+        f(a, b)
+    e = time.perf_counter_ns()
+    return (e - s) * 1e-9
+
+
+def make_mx_conv_transpose_2D(strides=(1, 1), padding=(0, 0), groups=1):
+    def mx_conv_transpose_2D(a, b):
+        ys = []
+        for i in range(N_iter_func):
+            y = mx.conv_transpose2d(
+                a, b, stride=strides, padding=padding, groups=groups
+            )
+            ys.append(y)
+        mx.eval(ys)
+        return ys
+
+    return mx_conv_transpose_2D
+
+
+def make_pt_conv_transpose_2D(strides=(1, 1), padding=(0, 0), groups=1):
+    @torch.no_grad()
+    def pt_conv_transpose_2D(a, b):
+        ys = []
+        for i in range(N_iter_func):
+            y = torch.conv_transpose2d(
+                a, b, stride=strides, padding=padding, groups=groups
+            )
+            ys.append(y)
+        torch.mps.synchronize()
+        return ys
+
+    return pt_conv_transpose_2D
+
+
+def bench_shape(N, H, W, C, kH, kW, O, strides, padding, groups, np_dtype):
+    scale = 1.0 / math.sqrt(kH * kH * C)
+    a_np = np.random.uniform(0, 0.5, (N, H, W, C)).astype(np_dtype)
+    b_np = np.random.uniform(-scale, scale, (O, kH, kW, int(C / groups))).astype(
+        np_dtype
+    )
+
+    a_mx = mx.array(a_np)
+    b_mx = mx.array(b_np)
+
+    a_pt = torch.from_numpy(a_np.transpose((0, 3, 1, 2))).to("mps")
+    b_pt = torch.from_numpy(b_np.transpose((3, 0, 1, 2))).to("mps")
+
+    torch.mps.synchronize()
+
+    f_mx = make_mx_conv_transpose_2D(strides, padding, groups)
+    f_pt = make_pt_conv_transpose_2D(strides, padding, groups)
+
+    time_torch = bench(f_pt, a_pt, b_pt)
+    time_mlx = bench(f_mx, a_mx, b_mx)
+
+    out_mx = mx.conv_transpose2d(
+        a_mx, b_mx, stride=strides, padding=padding, groups=groups
+    )
+    out_pt = torch.conv_transpose2d(
+        a_pt.to("cpu"), b_pt.to("cpu"), stride=strides, padding=padding, groups=groups
+    )
+    out_pt = torch.permute(out_pt, (0, 2, 3, 1))
+    out_pt = out_pt.numpy(force=True)
+
+    atol = 2e-5 if np_dtype == np.float32 else 1e-4
+
+    if not np.allclose(out_pt, out_mx, atol=atol):
+        print(
+            f"Failed at {(N, H, W, C)}, {(O, kH, kW, C)} [strides = {strides}, padding = {padding}, groups = {groups}] with max(|a - b|) = {np.max(np.abs(out_pt - out_mx))}"
+        )
+
+    return time_mlx, time_torch
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="Run conv benchmarks")
+
+    dtypes = ("float32",)
+    shapes = (
+        (4, 32, 32, 32, 5, 5, 32, (1, 1), (2, 2), 1),
+        (4, 32, 32, 64, 5, 5, 64, (1, 1), (2, 2), 1),
+        (4, 32, 32, 128, 5, 5, 128, (1, 1), (2, 2), 1),
+        (4, 32, 32, 256, 5, 5, 256, (1, 1), (2, 2), 1),
+        (4, 32, 32, 512, 5, 5, 512, (1, 1), (2, 2), 1),
+        (4, 64, 64, 32, 5, 5, 32, (1, 1), (2, 2), 1),
+        (4, 64, 64, 64, 5, 5, 64, (1, 1), (2, 2), 1),
+        (4, 64, 64, 128, 5, 5, 128, (1, 1), (2, 2), 1),
+        (4, 64, 64, 256, 5, 5, 256, (1, 1), (2, 2), 1),
+        (4, 128, 128, 32, 5, 5, 32, (1, 1), (2, 2), 1),
+        (4, 128, 128, 64, 5, 5, 64, (1, 1), (2, 2), 1),
+        (4, 128, 128, 128, 5, 5, 128, (1, 1), (2, 2), 1),
+        (4, 256, 256, 32, 5, 5, 3, (1, 1), (2, 2), 1),
+        (4, 256, 256, 3, 5, 5, 32, (1, 1), (2, 2), 1),
+        (4, 128, 128, 64, 5, 5, 3, (1, 1), (2, 2), 1),
+        (4, 128, 128, 3, 5, 5, 64, (1, 1), (2, 2), 1),
+    )
+
+    for dtype in dtypes:
+        print(
+            "(N,   H,   W,   C), (  O, kH, kW,   C),   dtype, stride,   pads,  groups, diff%"
+        )
+        for N, H, W, C, kH, kW, O, strides, padding, groups in shapes:
+            np_dtype = getattr(np, dtype)
+            time_mlx, time_torch = bench_shape(
+                N, H, W, C, kH, kW, O, strides, padding, groups, np_dtype
+            )
+            diff = time_torch / time_mlx - 1.0
+
+            print(
+                f"({N}, {H:3d}, {W:3d}, {C:3d}), ({O:3d}, {kH:2d}, {kW:2d}, {C:3d}), {dtype}, {strides}, {padding}, {groups:7d}, {100. * diff:+5.2f}%"
+            )
+            if time_mlx >= 2.0 * time_torch:
+                print("ATTENTION ^^^^^^^")

benchmarks/python/distributed_bench.py

@@ -0,0 +1,66 @@
+# Copyright © 2024 Apple Inc.
+
+"""
+Run with:
+    mpirun -n 2 python /path/to/distributed_bench.py
+"""
+
+import time
+
+import mlx.core as mx
+
+
+def time_fn(fn, *args, **kwargs):
+    msg = kwargs.pop("msg", None)
+    world = mx.distributed.init()
+    if world.rank() == 0:
+        if msg:
+            print(f"Timing {msg} ...", end=" ")
+        else:
+            print(f"Timing {fn.__name__} ...", end=" ")
+
+    # warmup
+    for _ in range(5):
+        mx.eval(fn(*args, **kwargs))
+
+    num_iters = 100
+    tic = time.perf_counter()
+    for _ in range(num_iters):
+        x = mx.eval(fn(*args, **kwargs))
+    toc = time.perf_counter()
+
+    msec = 1e3 * (toc - tic) / num_iters
+    if world.rank() == 0:
+        print(f"{msec:.5f} msec")
+
+
+def time_all_sum():
+    shape = (4096,)
+    x = mx.random.uniform(shape=shape)
+    mx.eval(x)
+
+    def sine(x):
+        for _ in range(20):
+            x = mx.sin(x)
+        return x
+
+    time_fn(sine, x)
+
+    def all_sum_plain(x):
+        for _ in range(20):
+            x = mx.distributed.all_sum(x)
+        return x
+
+    time_fn(all_sum_plain, x)
+
+    def all_sum_with_sine(x):
+        for _ in range(20):
+            x = mx.sin(x)
+            x = mx.distributed.all_sum(x)
+        return x
+
+    time_fn(all_sum_with_sine, x)
+
+
+if __name__ == "__main__":
+    time_all_sum()

benchmarks/python/einsum_bench.py

@@ -0,0 +1,84 @@
+# Copyright © 2024 Apple Inc.
+
+import time
+
+import mlx.core as mx
+import numpy as np
+
+
+def timeit(fn, its=100, args=[]):
+    for _ in range(5):
+        fn(*args)
+    tic = time.perf_counter()
+    for _ in range(its):
+        fn(*args)
+    toc = time.perf_counter()
+    return 1e3 * (toc - tic) / its
+
+
+def time_little_einsum_path():
+    subscripts = "ik,kj->ij"
+    x = mx.ones((32, 32))
+    y = mx.ones((32, 32))
+    mx_time = timeit(mx.einsum_path, args=(subscripts, x, y))
+
+    x = np.array(x)
+    y = np.array(y)
+    np_time = timeit(np.einsum_path, args=(subscripts, x, y))
+    print("Timing little einsum path...")
+    print(f"MLX ... {mx_time:.3f} ms")
+    print(f"NumPy... {np_time:.3f} ms")
+
+
+def time_big_einsum_path():
+    chars = list("abcdefgh")
+    char_to_dim = {c: v for v, c in enumerate(chars)}
+
+    num_inputs = 10
+    inputs = []
+    subscripts = []
+    for _ in range(num_inputs):
+        subscript = np.random.choice(chars, size=5, replace=False).tolist()
+        subscripts.append("".join(subscript))
+        inputs.append(np.ones(list(char_to_dim[c] for c in subscript)))
+    subscripts = ",".join(subscripts)
+
+    np_time = timeit(np.einsum_path, args=(subscripts, *inputs))
+
+    inputs = [mx.array(x) for x in inputs]
+    mx_time = timeit(mx.einsum_path, args=(subscripts, *inputs))
+    print("Timing big einsum path...")
+    print(f"MLX ... {mx_time:.3f} ms")
+    print(f"NumPy... {np_time:.3f} ms")
+
+
+def time_attention():
+    def regular_attention(x):
+        # shape [batch, sequence, num_heads, head_dim]
+        queries, keys, values = x, x, x
+        scores = queries.transpose(0, 2, 1, 3) @ keys.transpose(0, 2, 3, 1)
+        scores = mx.softmax(scores, axis=-1)
+        output = (scores @ values.transpose(0, 2, 1, 3)).swapaxes(1, 2)
+        mx.eval(output)
+
+    def einsum_attention(x):
+        # shape [batch, sequence, num_heads, head_dim]
+        queries, keys, values = x, x, x
+        scores = mx.einsum("itjk,iujk->ijtu", queries, keys)
+        scores = mx.softmax(scores, axis=-1)
+        output = mx.einsum("ijtu,iujk->itjk", scores, values)
+        mx.eval(output)
+
+    x = mx.random.uniform(shape=(8, 512, 32, 128))
+
+    regular_time = timeit(regular_attention, args=(x,))
+    ein_time = timeit(einsum_attention, args=(x,))
+    print("Timing einsum attention...")
+    print(f"Regular ... {regular_time:.3f} ms")
+    print(f"Einsum ... {ein_time:.3f} ms")
+
+
+if __name__ == "__main__":
+    time_little_einsum_path()
+    time_big_einsum_path()
+    time_attention()

benchmarks/python/hadamard_bench.py

@@ -0,0 +1,70 @@
+import argparse
+
+import matplotlib
+import mlx.core as mx
+import numpy as np
+from time_utils import measure_runtime
+
+matplotlib.use("Agg")
+import matplotlib.pyplot as plt
+
+
+def had(x):
+    y = mx.hadamard_transform(x)
+    mx.eval(y)
+
+
+def copy(x):
+    y = x + 1.0
+    mx.eval(y)
+
+
+def run(dtype):
+    system_size = 2**26
+    outputs = {}
+    for test_fn in (had, copy):
+        for m in [1, 12, 20, 28]:
+            if test_fn == copy:
+                key = "copy"
+            elif m == 1:
+                key = "had_2^k"
+            else:
+                key = "had_m*2^k"
+            outputs.setdefault(key, {})
+            for k in range(7, 14):
+                n = m * 2**k
+                if n > 2**15:
+                    continue
+                x_np = np.random.normal(size=(system_size // n, n)).astype(dtype)
+                x = mx.array(x_np)
+                runtime_ms = measure_runtime(test_fn, x=x)
+                bytes_per_gb = 1e9
+                ms_per_s = 1e3
+                bytes_per_had = np.dtype(x_np.dtype).itemsize * 2
+                bandwidth_gb = (
+                    system_size * bytes_per_had / runtime_ms * ms_per_s / bytes_per_gb
+                )
+                print(n, bandwidth_gb)
+                outputs[key][n] = bandwidth_gb
+
+    colors = {
+        "copy": "black",
+        "had_2^k": "steelblue",
+        "had_m*2^k": "skyblue",
+    }
+    for key, output in outputs.items():
+        plt.scatter(output.keys(), output.values(), color=colors[key], label=key)
+    plt.title(f"MLX Hadamard Benchmark -- {dtype.__name__}")
+    plt.xlabel("N")
+    plt.ylabel("Bandwidth (GB/s)")
+    plt.legend()
+    plt.savefig(f"bench_{dtype.__name__}.png")
+    plt.clf()
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--fp16", action="store_true")
+    args = parser.parse_args()
+    dtype = np.float16 if args.fp16 else np.float32
+    run(dtype)

cmake/extension.cmake

@@ -1,56 +1,41 @@
 include(CMakeParseArguments)
 
-###############################################################################
+# ##############################################################################
 # Build metal library
 #
 # Adds a custom target ${TARGET} to build ${OUTPUT_DIRECTORY}/{TITLE}.metallib
 # from list ${SOURCES}, including list ${INCLUDE_DIRS}, depends on list ${DEPS}
 #
-# Args:
-#     TARGET: Custom target to be added for the metal library 
-#     TITLE: Name of the .metallib
-#     OUTPUT_DIRECTORY: Where to place ${TITLE}.metallib
-#     SOURCES: List of source files
-#     INCLUDE_DIRS: List of include dirs
-#     DEPS: List of dependency files (like headers)
+# Args: TARGET: Custom target to be added for the metal library TITLE: Name of
+# the .metallib OUTPUT_DIRECTORY: Where to place ${TITLE}.metallib SOURCES: List
+# of source files INCLUDE_DIRS: List of include dirs DEPS: List of dependency
+# files (like headers)
 #
 macro(mlx_build_metallib)
   # Parse args
   set(oneValueArgs TARGET TITLE OUTPUT_DIRECTORY)
   set(multiValueArgs SOURCES INCLUDE_DIRS DEPS)
-  cmake_parse_arguments(
-      MTLLIB 
-      ""
-      "${oneValueArgs}"
-      "${multiValueArgs}" 
-      ${ARGN}
-  )
+  cmake_parse_arguments(MTLLIB "" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
 
   # Set output
   set(MTLLIB_BUILD_TARGET "${MTLLIB_OUTPUT_DIRECTORY}/${MTLLIB_TITLE}.metallib")
 
-  # Collect compile options 
+  # Collect compile options
   set(MTLLIB_COMPILE_OPTIONS -Wall -Wextra -fno-fast-math)
 
   # Prepare metallib build command
   add_custom_command(
     OUTPUT ${MTLLIB_BUILD_TARGET}
-    COMMAND xcrun -sdk macosx metal 
-                  "$<LIST:TRANSFORM,${MTLLIB_INCLUDE_DIRS},PREPEND,-I>"
-                  ${MTLLIB_COMPILE_OPTIONS}
-                  ${MTLLIB_SOURCES}
-                  -o ${MTLLIB_BUILD_TARGET}
+    COMMAND
+      xcrun -sdk macosx metal
+      "$<LIST:TRANSFORM,${MTLLIB_INCLUDE_DIRS},PREPEND,-I>"
+      ${MTLLIB_COMPILE_OPTIONS} ${MTLLIB_SOURCES} -o ${MTLLIB_BUILD_TARGET}
     DEPENDS ${MTLLIB_DEPS} ${MTLLIB_SOURCES}
     COMMAND_EXPAND_LISTS
     COMMENT "Building ${MTLLIB_TITLE}.metallib"
-    VERBATIM
-  )
+    VERBATIM)
 
   # Add metallib custom target
-  add_custom_target(
-    ${MTLLIB_TARGET}
-    DEPENDS
-    ${MTLLIB_BUILD_TARGET}
-  )
+  add_custom_target(${MTLLIB_TARGET} DEPENDS ${MTLLIB_BUILD_TARGET})
 
-endmacro(mlx_build_metallib)
+endmacro(mlx_build_metallib)

cmake/metal.14.0.diff

@@ -1,36 +0,0 @@
-diff -ur Metal/MTLEvent.hpp MetalNew/MTLEvent.hpp
---- Metal/MTLEvent.hpp	2023-06-01 12:18:26
-+++ MetalNew/MTLEvent.hpp	2024-04-15 07:36:59
-@@ -62,6 +62,7 @@
- 
-     uint64_t                 signaledValue() const;
-     void                     setSignaledValue(uint64_t signaledValue);
-+    bool                     waitUntilSignaledValue(uint64_t signaledValue, uint64_t timeoutMS);
- };
- 
- class SharedEventHandle : public NS::SecureCoding<SharedEventHandle>
-@@ -138,6 +139,11 @@
- _MTL_INLINE void MTL::SharedEvent::setSignaledValue(uint64_t signaledValue)
- {
-     Object::sendMessage<void>(this, _MTL_PRIVATE_SEL(setSignaledValue_), signaledValue);
-+}
-+
-+// method: waitUntilSignaledValue
-+_MTL_INLINE bool MTL::SharedEvent::waitUntilSignaledValue(uint64_t signaledValue, uint64_t timeoutMS) {
-+    return Object::sendMessage<bool>(this, _MTL_PRIVATE_SEL(waitUntilSignaledValue_timeoutMS_), signaledValue, timeoutMS);
- }
- 
- // static method: alloc
-diff -ur Metal/MTLHeaderBridge.hpp MetalNew/MTLHeaderBridge.hpp
---- Metal/MTLHeaderBridge.hpp	2023-06-01 12:18:26
-+++ MetalNew/MTLHeaderBridge.hpp	2024-04-15 07:37:29
-@@ -1906,6 +1906,9 @@
-     "setShouldMaximizeConcurrentCompilation:");
- _MTL_PRIVATE_DEF_SEL(setSignaledValue_,
-     "setSignaledValue:");
-+_MTL_PRIVATE_DEF_SEL(
-+    waitUntilSignaledValue_timeoutMS_,
-+    "waitUntilSignaledValue:timeoutMS:");
- _MTL_PRIVATE_DEF_SEL(setSize_,
-     "setSize:");
- _MTL_PRIVATE_DEF_SEL(setSlice_,

cmake/metal.14.2.diff

@@ -1,36 +0,0 @@
-diff -ur Metal/MTLEvent.hpp MetalNew/MTLEvent.hpp
---- Metal/MTLEvent.hpp	2024-04-15 07:12:10
-+++ MetalNew/MTLEvent.hpp	2024-04-15 07:15:50
-@@ -62,6 +62,7 @@
- 
-     uint64_t                 signaledValue() const;
-     void                     setSignaledValue(uint64_t signaledValue);
-+    bool                     waitUntilSignaledValue(uint64_t signaledValue, uint64_t timeoutMS);
- };
- 
- class SharedEventHandle : public NS::SecureCoding<SharedEventHandle>
-@@ -138,6 +139,11 @@
- _MTL_INLINE void MTL::SharedEvent::setSignaledValue(uint64_t signaledValue)
- {
-     Object::sendMessage<void>(this, _MTL_PRIVATE_SEL(setSignaledValue_), signaledValue);
-+}
-+
-+// method: waitUntilSignaledValue
-+_MTL_INLINE bool MTL::SharedEvent::waitUntilSignaledValue(uint64_t signaledValue, uint64_t timeoutMS) {
-+    return Object::sendMessage<bool>(this, _MTL_PRIVATE_SEL(waitUntilSignaledValue_timeoutMS_), signaledValue, timeoutMS);
- }
- 
- // static method: alloc
-diff -ur Metal/MTLHeaderBridge.hpp MetalNew/MTLHeaderBridge.hpp
---- Metal/MTLHeaderBridge.hpp	2024-04-15 07:12:10
-+++ MetalNew/MTLHeaderBridge.hpp	2024-04-15 07:16:15
-@@ -1918,6 +1918,9 @@
-     "setShouldMaximizeConcurrentCompilation:");
- _MTL_PRIVATE_DEF_SEL(setSignaledValue_,
-     "setSignaledValue:");
-+_MTL_PRIVATE_DEF_SEL(
-+    waitUntilSignaledValue_timeoutMS_,
-+    "waitUntilSignaledValue:timeoutMS:");
- _MTL_PRIVATE_DEF_SEL(setSize_,
-     "setSize:");
- _MTL_PRIVATE_DEF_SEL(setSlice_,

docs/requirements.txt

@@ -1,3 +1,4 @@
 sphinx
 breathe
 sphinx-book-theme
+mlx

docs/src/conf.py

@@ -83,3 +83,15 @@ def setup(app):
 # -- Options for LaTeX output ------------------------------------------------
 
 latex_documents = [(main_doc, "MLX.tex", "MLX Documentation", author, "manual")]
+latex_elements = {
+    "preamble": r"""
+    \usepackage{enumitem}
+    \setlistdepth{5}
+    \setlist[itemize,1]{label=$\bullet$}
+    \setlist[itemize,2]{label=$\bullet$}
+    \setlist[itemize,3]{label=$\bullet$}
+    \setlist[itemize,4]{label=$\bullet$}
+    \setlist[itemize,5]{label=$\bullet$}
+    \renewlist{itemize}{itemize}{5}
+""",
+}

docs/src/dev/custom_metal_kernels.rst

@@ -0,0 +1,421 @@
+Custom Metal Kernels
+====================
+
+MLX supports writing custom Metal kernels through the Python and C++ APIs.
+
+Simple Example
+--------------
+
+Let's write a custom kernel that computes ``exp`` elementwise:
+
+.. code-block:: python
+
+  def exp_elementwise(a: mx.array):
+      source = """
+          uint elem = thread_position_in_grid.x;
+          T tmp = inp[elem];
+          out[elem] = metal::exp(tmp);
+      """
+
+      kernel = mx.fast.metal_kernel(
+          name="myexp",
+          input_names=["inp"],
+          output_names=["out"],
+          source=source,
+      )
+      outputs = kernel(
+          inputs=[a],
+          template=[("T", mx.float32)],
+          grid=(a.size, 1, 1),
+          threadgroup=(256, 1, 1),
+          output_shapes=[a.shape],
+          output_dtypes=[a.dtype],
+      )
+      return outputs[0]
+
+  a = mx.random.normal(shape=(4, 16)).astype(mx.float16)
+  b = exp_elementwise(a)
+  assert mx.allclose(b, mx.exp(a))
+
+.. note::
+    We are only required to pass the body of the Metal kernel in ``source``.
+
+The full function signature will be generated using:
+
+* The shapes/dtypes of ``inputs``
+    In the above, ``a`` is an ``mx.array`` of type ``mx.float16`` and we pass it with the key ``inp``
+    so we will add ``const device float16_t* inp`` to the signature.
+    ``inp_shape``, ``inp_strides`` and ``inp_ndim`` are also added for convenience if they are present
+    in ``source``.
+* The list of ``output_dtypes``
+    In the above, ``out`` is an ``mx.array`` of type ``mx.float16``
+    so we add ``device float16_t* out``.
+* Template parameters passed using ``template``
+    In the above, ``template=[("T", mx.float32)]`` adds a template of ``template <typename T>`` to the function
+    and instantiates the template with ``custom_kernel_myexp_float<float>``.
+    Template parameters can be ``mx.core.Dtype``, ``int`` or ``bool``.
+* Metal attributes used in ``source`` such as ``[[thread_position_in_grid]]``
+    These will be added as function arguments.
+    All the attributes defined in Table 5.8 of the `Metal Shading Language Specification <https://developer.apple.com/metal/Metal-Shading-Language-Specification.pdf>`_ are supported.
+
+Putting this all together, the generated function signature for ``myexp`` is as follows:
+
+.. code-block:: cpp
+
+  template <typename T>
+  [[kernel]] void custom_kernel_myexp_float(
+    const device float16_t* inp [[buffer(0)]],
+    device float16_t* out [[buffer(1)]],
+    uint3 thread_position_in_grid [[thread_position_in_grid]]) {
+
+          uint elem = thread_position_in_grid.x;
+          T tmp = inp[elem];
+          out[elem] = metal::exp(tmp);
+
+  }
+
+  template [[host_name("custom_kernel_myexp_float")]] [[kernel]] decltype(custom_kernel_myexp_float<float>) custom_kernel_myexp_float<float>;
+
+Passing ``verbose=True`` to ``mx.fast.metal_kernel.__call__`` will print the generated code for debugging purposes.
+
+Using Shape/Strides
+-------------------
+
+``mx.fast.metal_kernel`` supports an argument ``ensure_row_contiguous`` which is ``True`` by default.
+This will copy the ``mx.array`` inputs if needed before the kernel is launched to ensure that the memory layout is row contiguous.
+Generally this makes writing the kernel easier, since we don't have to worry about gaps or the ordering of the dims
+when indexing.
+
+If we want to avoid this copy, ``metal_kernel`` automatically passes ``a_shape``, ``a_strides`` and ``a_ndim`` for each
+input array ``a`` if any are present in ``source``.
+We can then use MLX's built in indexing utils to fetch the right elements for each thread.
+
+Let's convert ``myexp`` above to support arbitrarily strided arrays without relying on a copy from ``ensure_row_contiguous``:
+
+.. code-block:: python
+
+  def exp_elementwise(a: mx.array):
+      source = """
+          uint elem = thread_position_in_grid.x;
+          // Utils from `mlx/backend/metal/kernels/utils.h` are automatically included
+          uint loc = elem_to_loc(elem, inp_shape, inp_strides, inp_ndim);
+          T tmp = inp[loc];
+          // Output arrays are always row contiguous
+          out[elem] = metal::exp(tmp);
+      """
+
+      kernel = mx.fast.metal_kernel(
+          name="myexp_strided",
+          input_names=["inp"],
+          output_names=["out"],
+          source=source
+      )
+      outputs = kernel(
+          inputs=[a],
+          template=[("T", mx.float32)],
+          grid=(a.size, 1, 1),
+          threadgroup=(256, 1, 1),
+          output_shapes=[a.shape],
+          output_dtypes=[a.dtype],
+          ensure_row_contiguous=False,
+      )
+      return outputs[0]
+
+  a = mx.random.normal(shape=(4, 16)).astype(mx.float16)
+  # make non-contiguous
+  a = a[::2]
+  b = exp_elementwise(a)
+  assert mx.allclose(b, mx.exp(a))
+
+Complex Example
+-----------------------------
+
+Let's implement a more complex example: ``grid_sample`` in ``"bilinear"`` mode.
+
+We'll start with the following MLX implementation using standard ops:
+
+.. code-block:: python
+
+    def grid_sample_ref(x, grid):
+        N, H_in, W_in, _ = x.shape
+        ix = ((grid[..., 0] + 1) * W_in - 1) / 2
+        iy = ((grid[..., 1] + 1) * H_in - 1) / 2
+
+        ix_nw = mx.floor(ix).astype(mx.int32)
+        iy_nw = mx.floor(iy).astype(mx.int32)
+
+        ix_ne = ix_nw + 1
+        iy_ne = iy_nw
+
+        ix_sw = ix_nw
+        iy_sw = iy_nw + 1
+
+        ix_se = ix_nw + 1
+        iy_se = iy_nw + 1
+
+        nw = (ix_se - ix)    * (iy_se - iy)
+        ne = (ix    - ix_sw) * (iy_sw - iy)
+        sw = (ix_ne - ix)    * (iy    - iy_ne)
+        se = (ix    - ix_nw) * (iy    - iy_nw)
+
+        I_nw = x[mx.arange(N)[:, None, None], iy_nw, ix_nw, :]
+        I_ne = x[mx.arange(N)[:, None, None], iy_ne, ix_ne, :]
+        I_sw = x[mx.arange(N)[:, None, None], iy_sw, ix_sw, :]
+        I_se = x[mx.arange(N)[:, None, None], iy_se, ix_se, :]
+
+        mask_nw = (iy_nw >= 0) & (iy_nw <= H_in - 1) & (ix_nw >= 0) & (ix_nw <= W_in - 1)
+        mask_ne = (iy_ne >= 0) & (iy_ne <= H_in - 1) & (ix_ne >= 0) & (ix_ne <= W_in - 1)
+        mask_sw = (iy_sw >= 0) & (iy_sw <= H_in - 1) & (ix_sw >= 0) & (ix_sw <= W_in - 1)
+        mask_se = (iy_se >= 0) & (iy_se <= H_in - 1) & (ix_se >= 0) & (ix_se <= W_in - 1)
+
+        I_nw *= mask_nw[..., None]
+        I_ne *= mask_ne[..., None]
+        I_sw *= mask_sw[..., None]
+        I_se *= mask_se[..., None]
+
+        output = nw[..., None] * I_nw + ne[..., None] * I_ne + sw[..., None] * I_sw + se[..., None] * I_se
+
+        return output
+
+Now let's use ``mx.custom_function`` together with ``mx.fast.metal_kernel``
+to write a fast GPU kernel for both the forward and backward passes.
+
+First we'll implement the forward pass as a fused kernel:
+
+.. code-block:: python
+
+    @mx.custom_function
+    def grid_sample(x, grid):
+
+        assert x.ndim == 4, "`x` must be 4D."
+        assert grid.ndim == 4, "`grid` must be 4D."
+
+        B, _, _, C = x.shape
+        _, gN, gM, D = grid.shape
+        out_shape = (B, gN, gM, C)
+
+        assert D == 2, "Last dim of `grid` must be size 2."
+
+        source = """
+            uint elem = thread_position_in_grid.x;
+            int H = x_shape[1];
+            int W = x_shape[2];
+            int C = x_shape[3];
+            int gH = grid_shape[1];
+            int gW = grid_shape[2];
+
+            int w_stride = C;
+            int h_stride = W * w_stride;
+            int b_stride = H * h_stride;
+
+            uint grid_idx = elem / C * 2;
+            float ix = ((grid[grid_idx] + 1) * W - 1) / 2;
+            float iy = ((grid[grid_idx + 1] + 1) * H - 1) / 2;
+
+            int ix_nw = floor(ix);
+            int iy_nw = floor(iy);
+
+            int ix_ne = ix_nw + 1;
+            int iy_ne = iy_nw;
+
+            int ix_sw = ix_nw;
+            int iy_sw = iy_nw + 1;
+
+            int ix_se = ix_nw + 1;
+            int iy_se = iy_nw + 1;
+
+            T nw = (ix_se - ix)    * (iy_se - iy);
+            T ne = (ix    - ix_sw) * (iy_sw - iy);
+            T sw = (ix_ne - ix)    * (iy    - iy_ne);
+            T se = (ix    - ix_nw) * (iy    - iy_nw);
+
+            int batch_idx = elem / C / gH / gW * b_stride;
+            int channel_idx = elem % C;
+            int base_idx = batch_idx + channel_idx;
+
+            T I_nw = x[base_idx + iy_nw * h_stride + ix_nw * w_stride];
+            T I_ne = x[base_idx + iy_ne * h_stride + ix_ne * w_stride];
+            T I_sw = x[base_idx + iy_sw * h_stride + ix_sw * w_stride];
+            T I_se = x[base_idx + iy_se * h_stride + ix_se * w_stride];
+
+            I_nw = iy_nw >= 0 && iy_nw <= H - 1 && ix_nw >= 0 && ix_nw <= W - 1 ? I_nw : 0;
+            I_ne = iy_ne >= 0 && iy_ne <= H - 1 && ix_ne >= 0 && ix_ne <= W - 1 ? I_ne : 0;
+            I_sw = iy_sw >= 0 && iy_sw <= H - 1 && ix_sw >= 0 && ix_sw <= W - 1 ? I_sw : 0;
+            I_se = iy_se >= 0 && iy_se <= H - 1 && ix_se >= 0 && ix_se <= W - 1 ? I_se : 0;
+
+            out[elem] = nw * I_nw + ne * I_ne + sw * I_sw + se * I_se;
+        """
+        kernel = mx.fast.metal_kernel(
+            name="grid_sample",
+            input_names=["x", "grid"],
+            output_names=["out"],
+            source=source,
+        )
+        outputs = kernel(
+            inputs=[x, grid],
+            template=[("T", x.dtype)],
+            output_shapes=[out_shape],
+            output_dtypes=[x.dtype],
+            grid=(np.prod(out_shape), 1, 1),
+            threadgroup=(256, 1, 1),
+        )
+        return outputs[0]
+
+For a reasonably sized input such as:
+
+.. code-block:: python
+
+    x.shape = (8, 1024, 1024, 64)
+    grid.shape = (8, 256, 256, 2)
+
+On an M1 Max, we see a big performance improvement:
+
+``55.7ms -> 6.7ms => 8x speed up``
+
+Grid Sample VJP
+---------------
+
+Since we decorated ``grid_sample`` with ``mx.custom_function``, we can now define
+its custom vjp transform so MLX can differentiate it.
+
+The backwards pass requires atomically updating ``x_grad``/``grid_grad`` and so
+requires a few extra ``mx.fast.metal_kernel`` features:
+
+* ``init_value=0``
+    Initialize all of the kernel's outputs to this value before it runs. This allows us to update only part of the output arrays with the kernel.
+
+* ``atomic_outputs=True``
+    Designate all of the kernel outputs as ``atomic`` in the function signature. 
+    This means we can use Metal's ``atomic`` features to simultaneously update the ``x_grad`` and ``grid_grad`` arrays from multiple threadgroups. 
+    See section 6.15 of the `Metal Shading Language Specification <https://developer.apple.com/metal/Metal-Shading-Language-Specification.pdf>`_ for more details.
+
+We can then implement the backwards pass as follows:
+
+.. code-block:: python
+
+    @grid_sample.vjp
+    def grid_sample_vjp(primals, cotangent, _):
+        x, grid = primals
+        B, _, _, C = x.shape
+        _, gN, gM, D = grid.shape
+
+        assert D == 2, "Last dim of `grid` must be size 2."
+
+        source = """
+            uint elem = thread_position_in_grid.x;
+            int H = x_shape[1];
+            int W = x_shape[2];
+            int C = x_shape[3];
+            // Pad C to the nearest larger simdgroup size multiple
+            int C_padded = ceildiv(C, threads_per_simdgroup) * threads_per_simdgroup;
+
+            int gH = grid_shape[1];
+            int gW = grid_shape[2];
+
+            int w_stride = C;
+            int h_stride = W * w_stride;
+            int b_stride = H * h_stride;
+
+            uint grid_idx = elem / C_padded * 2;
+            float ix = ((grid[grid_idx] + 1) * W - 1) / 2;
+            float iy = ((grid[grid_idx + 1] + 1) * H - 1) / 2;
+
+            int ix_nw = floor(ix);
+            int iy_nw = floor(iy);
+
+            int ix_ne = ix_nw + 1;
+            int iy_ne = iy_nw;
+
+            int ix_sw = ix_nw;
+            int iy_sw = iy_nw + 1;
+
+            int ix_se = ix_nw + 1;
+            int iy_se = iy_nw + 1;
+
+            T nw = (ix_se - ix)    * (iy_se - iy);
+            T ne = (ix    - ix_sw) * (iy_sw - iy);
+            T sw = (ix_ne - ix)    * (iy    - iy_ne);
+            T se = (ix    - ix_nw) * (iy    - iy_nw);
+
+            int batch_idx = elem / C_padded / gH / gW * b_stride;
+            int channel_idx = elem % C_padded;
+            int base_idx = batch_idx + channel_idx;
+
+            T gix = T(0);
+            T giy = T(0);
+            if (channel_idx < C) {
+                int cot_index = elem / C_padded * C + channel_idx;
+                T cot = cotangent[cot_index];
+                if (iy_nw >= 0 && iy_nw <= H - 1 && ix_nw >= 0 && ix_nw <= W - 1) {
+                    int offset = base_idx + iy_nw * h_stride + ix_nw * w_stride;
+                    atomic_fetch_add_explicit(&x_grad[offset], nw * cot, memory_order_relaxed);
+
+                    T I_nw = x[offset];
+                    gix -= I_nw * (iy_se - iy) * cot;
+                    giy -= I_nw * (ix_se - ix) * cot;
+                }
+                if (iy_ne >= 0 && iy_ne <= H - 1 && ix_ne >= 0 && ix_ne <= W - 1) {
+                    int offset = base_idx + iy_ne * h_stride + ix_ne * w_stride;
+                    atomic_fetch_add_explicit(&x_grad[offset], ne * cot, memory_order_relaxed);
+
+                    T I_ne = x[offset];
+                    gix += I_ne * (iy_sw - iy) * cot;
+                    giy -= I_ne * (ix - ix_sw) * cot;
+                }
+                if (iy_sw >= 0 && iy_sw <= H - 1 && ix_sw >= 0 && ix_sw <= W - 1) {
+                    int offset = base_idx + iy_sw * h_stride + ix_sw * w_stride;
+                    atomic_fetch_add_explicit(&x_grad[offset], sw * cot, memory_order_relaxed);
+
+                    T I_sw = x[offset];
+                    gix -= I_sw * (iy - iy_ne) * cot;
+                    giy += I_sw * (ix_ne - ix) * cot;
+                }
+                if (iy_se >= 0 && iy_se <= H - 1 && ix_se >= 0 && ix_se <= W - 1) {
+                    int offset = base_idx + iy_se * h_stride + ix_se * w_stride;
+                    atomic_fetch_add_explicit(&x_grad[offset], se * cot, memory_order_relaxed);
+
+                    T I_se = x[offset];
+                    gix += I_se * (iy - iy_nw) * cot;
+                    giy += I_se * (ix - ix_nw) * cot;
+                }
+            }
+
+            T gix_mult = W / 2;
+            T giy_mult = H / 2;
+
+            // Reduce across each simdgroup first.
+            // This is much faster than relying purely on atomics.
+            gix = simd_sum(gix);
+            giy = simd_sum(giy);
+
+            if (thread_index_in_simdgroup == 0) {
+                atomic_fetch_add_explicit(&grid_grad[grid_idx], gix * gix_mult, memory_order_relaxed);
+                atomic_fetch_add_explicit(&grid_grad[grid_idx + 1], giy * giy_mult, memory_order_relaxed);
+            }
+        """
+        kernel = mx.fast.metal_kernel(
+            name="grid_sample_grad",
+            input_names=["x", "grid", "cotangent"],
+            output_names=["x_grad", "grid_grad"],
+            source=source,
+            atomic_outputs=True,
+        )
+        # pad the output channels to simd group size
+        # so that our `simd_sum`s don't overlap.
+        simdgroup_size = 32
+        C_padded = (C + simdgroup_size - 1) // simdgroup_size * simdgroup_size
+        grid_size = B * gN * gM * C_padded
+        outputs = kernel(
+            inputs=[x, grid, cotangent],
+            template=[("T", x.dtype)],
+            output_shapes=[x.shape, grid.shape],
+            output_dtypes=[x.dtype, x.dtype],
+            grid=(grid_size, 1, 1),
+            threadgroup=(256, 1, 1),
+            init_value=0,
+        )
+        return outputs[0], outputs[1]
+
+There's an even larger speed up for the vjp:
+
+``676.4ms -> 16.7ms => 40x speed up``

docs/src/dev/extensions.rst

@@ -486,9 +486,8 @@ below.
         std::ostringstream kname;
         kname << "axpby_" << "general_" << type_to_name(out);
 
-        // Make sure the metal library is available and look for it
-        // in the same folder as this executable if needed
-        d.register_library("mlx_ext", metal::get_colocated_mtllib_path);
+        // Make sure the metal library is available
+        d.register_library("mlx_ext");
 
         // Make a kernel from this metal library
         auto kernel = d.get_kernel(kname.str(), "mlx_ext");

docs/src/examples/llama-inference.rst

@@ -15,7 +15,7 @@ module to concisely define the model architecture.
 Attention layer
 ^^^^^^^^^^^^^^^^
 
-We will start with the llama attention layer which notably uses the RoPE
+We will start with the Llama attention layer which notably uses the RoPE
 positional encoding. [1]_ In addition, our attention layer will optionally use a
 key/value cache that will be concatenated with the provided keys and values to
 support efficient inference.

docs/src/examples/mlp.rst

@@ -64,7 +64,7 @@ set:
 Next, setup the problem parameters and load the data. To load the data, you need our
 `mnist data loader
 <https://github.com/ml-explore/mlx-examples/blob/main/mnist/mnist.py>`_, which
-we will import as `mnist`.
+we will import as ``mnist``.
 
 .. code-block:: python
 

docs/src/index.rst

@@ -85,3 +85,4 @@ are the CPU and GPU.
 
    dev/extensions
    dev/metal_debugger
+   dev/custom_metal_kernels

docs/src/install.rst

@@ -70,36 +70,36 @@ To build and install the MLX python library from source, first, clone MLX from
 
    git clone git@github.com:ml-explore/mlx.git mlx && cd mlx
 
-Install `nanobind <https://nanobind.readthedocs.io/en/latest/>`_ with:
-
-.. code-block:: shell
-
-    pip install git+https://github.com/wjakob/nanobind.git@2f04eac452a6d9142dedb957701bdb20125561e4
-
 Then simply build and install MLX using pip:
 
 .. code-block:: shell
 
-   env CMAKE_BUILD_PARALLEL_LEVEL="" pip install .
+  CMAKE_BUILD_PARALLEL_LEVEL=8 pip install .
 
-For developing use an editable install:
+For developing, install the package with development dependencies, and use an
+editable install:
 
 .. code-block:: shell
 
-  env CMAKE_BUILD_PARALLEL_LEVEL="" pip install -e .
+  CMAKE_BUILD_PARALLEL_LEVEL=8 pip install -e ".[dev]"
 
-To make sure the install is working run the tests with:
+Once the development dependencies are installed, you can build faster with:
+
+.. code-block:: shell
+
+ CMAKE_BUILD_PARALLEL_LEVEL=8 python setup.py build_ext --inplace
+
+Run the tests with:
 
 .. code-block:: shell
 
-  pip install ".[testing]"
   python -m unittest discover python/tests
 
-Optional: Install stubs to enable auto completions and type checking from your IDE:
+Optional: Install stubs to enable auto completions and type checking from your
+IDE:
 
 .. code-block:: shell
 
-  pip install ".[dev]"
   python setup.py generate_stubs
 
 C++ API
@@ -195,7 +195,7 @@ GGUF, you can do:
 
 .. code-block:: shell
 
-  cmake ..
+  cmake .. \
     -DCMAKE_BUILD_TYPE=MinSizeRel \
     -DBUILD_SHARED_LIBS=ON \
     -DMLX_BUILD_CPU=OFF \

docs/src/python/array.rst

@@ -24,6 +24,7 @@ Array
     array.any
     array.argmax
     array.argmin
+    array.conj
     array.cos
     array.cummax
     array.cummin
@@ -52,8 +53,10 @@ Array
     array.sqrt
     array.square
     array.squeeze
-    array.swapaxes
+    array.std
     array.sum
+    array.swapaxes
     array.transpose
     array.T
     array.var
+    array.view

docs/src/python/distributed.rst

@@ -17,3 +17,6 @@ made available.
     init
     all_sum
     all_gather
+    send
+    recv
+    recv_like

docs/src/python/fast.rst

@@ -12,3 +12,5 @@ Fast
   layer_norm
   rope
   scaled_dot_product_attention
+  affine_quantize
+  metal_kernel

docs/src/python/linalg.rst

@@ -9,7 +9,10 @@ Linear Algebra
    :toctree: _autosummary 
 
     inv
+    tri_inv
     norm
     cholesky
+    cholesky_inv
+    cross
     qr
     svd

docs/src/python/nn/functions.rst

@@ -13,6 +13,7 @@ simple functions.
    :template: nn-module-template.rst
 
    elu
+   celu
    gelu
    gelu_approx
    gelu_fast_approx

docs/src/python/nn/layers.rst

@@ -13,13 +13,18 @@ Layers
    AvgPool1d
    AvgPool2d
    BatchNorm
+   CELU
    Conv1d
    Conv2d
    Conv3d
+   ConvTranspose1d
+   ConvTranspose2d
+   ConvTranspose3d
    Dropout
    Dropout2d
    Dropout3d
    Embedding
+   ELU
    GELU
    GLU
    GroupNorm
@@ -31,6 +36,8 @@ Layers
    LayerNorm
    LeakyReLU
    Linear
+   LogSigmoid
+   LogSoftmax
    LSTM
    MaxPool1d
    MaxPool2d
@@ -46,6 +53,7 @@ Layers
    RoPE
    SELU
    Sequential
+   Sigmoid
    SiLU
    SinusoidalPositionalEncoding
    Softmin

docs/src/python/ops.rst

@@ -44,6 +44,10 @@ Operations
    convolve
    conv1d
    conv2d
+   conv3d
+   conv_transpose1d
+   conv_transpose2d
+   conv_transpose3d
    conv_general
    cos
    cosh
@@ -57,6 +61,8 @@ Operations
    diagonal
    divide
    divmod
+   einsum
+   einsum_path
    equal
    erf
    erfinv
@@ -72,8 +78,10 @@ Operations
    gather_qmm
    greater
    greater_equal
+   hadamard_transform
    identity
    inner
+   isfinite
    isclose
    isinf
    isnan
@@ -103,6 +111,7 @@ Operations
    minimum
    moveaxis
    multiply
+   nan_to_num
    negative
    not_equal
    ones
@@ -112,6 +121,7 @@ Operations
    pad
    power
    prod
+   put_along_axis
    quantize
    quantized_matmul
    radians
@@ -120,6 +130,7 @@ Operations
    repeat
    reshape
    right_shift
+   roll
    round
    rsqrt
    save

docs/src/python/optimizers.rst

@@ -31,6 +31,41 @@ model's parameters and the **optimizer state**.
             # Compute the new parameters but also the optimizer state.
             mx.eval(model.parameters(), optimizer.state)
 
+Saving and Loading
+------------------
+
+To serialize an optimizer, save its state. To load an optimizer, load and set
+the saved state. Here's a simple example:
+
+.. code-block:: python
+
+   import mlx.core as mx
+   from mlx.utils import tree_flatten, tree_unflatten
+   import mlx.optimizers as optim
+
+   optimizer = optim.Adam(learning_rate=1e-2)
+
+   # Perform some updates with the optimizer
+   model = {"w" : mx.zeros((5, 5))}
+   grads = {"w" : mx.ones((5, 5))}
+   optimizer.update(model, grads)
+
+   # Save the state
+   state = tree_flatten(optimizer.state)
+   mx.save_safetensors("optimizer.safetensors", dict(state))
+
+   # Later on, for example when loading from a checkpoint,
+   # recreate the optimizer and load the state
+   optimizer = optim.Adam(learning_rate=1e-2)
+
+   state = tree_unflatten(list(mx.load("optimizer.safetensors").items()))
+   optimizer.state = state
+
+Note, not every optimizer configuation parameter is saved in the state. For
+example, for Adam the learning rate is saved but the ``betas`` and ``eps``
+parameters are not. A good rule of thumb is if the parameter can be scheduled
+then it will be included in the optimizer state.
+
 .. toctree::
 
    optimizers/optimizer

docs/src/python/random.rst

@@ -44,3 +44,5 @@ we use a splittable version of Threefry, which is a counter-based PRNG.
    split
    truncated_normal
    uniform
+   laplace
+   permutation

docs/src/python/transforms.rst

@@ -10,6 +10,7 @@ Transforms
 
    eval
    compile
+   custom_function
    disable_compile
    enable_compile
    grad

examples/extensions/CMakeLists.txt

@@ -11,10 +11,14 @@ option(BUILD_SHARED_LIBS "Build extensions as a shared library" ON)
 
 # ----------------------------- Dependencies -----------------------------
 find_package(MLX CONFIG REQUIRED)
-find_package(Python 3.8 COMPONENTS Interpreter Development.Module REQUIRED)
+find_package(
+  Python 3.8
+  COMPONENTS Interpreter Development.Module
+  REQUIRED)
 execute_process(
   COMMAND "${Python_EXECUTABLE}" -m nanobind --cmake_dir
-  OUTPUT_STRIP_TRAILING_WHITESPACE OUTPUT_VARIABLE NB_DIR)
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  OUTPUT_VARIABLE NB_DIR)
 list(APPEND CMAKE_PREFIX_PATH "${NB_DIR}")
 find_package(nanobind CONFIG REQUIRED)
 
@@ -24,16 +28,10 @@ find_package(nanobind CONFIG REQUIRED)
 add_library(mlx_ext)
 
 # Add sources
-target_sources(
-  mlx_ext
-  PUBLIC
-  ${CMAKE_CURRENT_LIST_DIR}/axpby/axpby.cpp
-)
+target_sources(mlx_ext PUBLIC ${CMAKE_CURRENT_LIST_DIR}/axpby/axpby.cpp)
 
 # Add include headers
-target_include_directories(
-  mlx_ext PUBLIC ${CMAKE_CURRENT_LIST_DIR}
-)
+target_include_directories(mlx_ext PUBLIC ${CMAKE_CURRENT_LIST_DIR})
 
 # Link to mlx
 target_link_libraries(mlx_ext PUBLIC mlx)
@@ -43,27 +41,32 @@ target_link_libraries(mlx_ext PUBLIC mlx)
 # Build metallib
 if(MLX_BUILD_METAL)
   mlx_build_metallib(
-    TARGET mlx_ext_metallib
-    TITLE mlx_ext
-    SOURCES ${CMAKE_CURRENT_LIST_DIR}/axpby/axpby.metal
-    INCLUDE_DIRS ${PROJECT_SOURCE_DIR} ${MLX_INCLUDE_DIRS}
-    OUTPUT_DIRECTORY ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}
-  )
-
-  add_dependencies(
-    mlx_ext
+    TARGET
     mlx_ext_metallib
-  )
+    TITLE
+    mlx_ext
+    SOURCES
+    ${CMAKE_CURRENT_LIST_DIR}/axpby/axpby.metal
+    INCLUDE_DIRS
+    ${PROJECT_SOURCE_DIR}
+    ${MLX_INCLUDE_DIRS}
+    OUTPUT_DIRECTORY
+    ${CMAKE_LIBRARY_OUTPUT_DIRECTORY})
+
+  add_dependencies(mlx_ext mlx_ext_metallib)
 
 endif()
 
 # ----------------------------- Python Bindings -----------------------------
 nanobind_add_module(
   _ext
-  NB_STATIC STABLE_ABI LTO NOMINSIZE
-  NB_DOMAIN mlx 
-  ${CMAKE_CURRENT_LIST_DIR}/bindings.cpp
-)
+  NB_STATIC
+  STABLE_ABI
+  LTO
+  NOMINSIZE
+  NB_DOMAIN
+  mlx
+  ${CMAKE_CURRENT_LIST_DIR}/bindings.cpp)
 target_link_libraries(_ext PRIVATE mlx_ext)
 
 if(BUILD_SHARED_LIBS)

examples/extensions/axpby/axpby.cpp

@@ -249,9 +249,8 @@ void Axpby::eval_gpu(
   kname << (contiguous_kernel ? "contiguous_" : "general_");
   kname << type_to_name(out);
 
-  // Make sure the metal library is available and look for it
-  // in the same folder as this executable if needed
-  d.register_library("mlx_ext", metal::get_colocated_mtllib_path);
+  // Make sure the metal library is available
+  d.register_library("mlx_ext");
 
   // Make a kernel from this metal library
   auto kernel = d.get_kernel(kname.str(), "mlx_ext");

examples/extensions/pyproject.toml

@@ -2,7 +2,7 @@
 requires = [
   "setuptools>=42",
   "cmake>=3.24",
-  "mlx>=0.9.0",
-  "nanobind@git+https://github.com/wjakob/nanobind.git@2f04eac452a6d9142dedb957701bdb20125561e4",
+  "mlx>=0.18.0",
+  "nanobind==2.2.0",
 ]
 build-backend = "setuptools.build_meta"

examples/extensions/requirements.txt

@@ -1,4 +1,4 @@
 setuptools>=42
 cmake>=3.24
-mlx>=0.9.0
-nanobind@git+https://github.com/wjakob/nanobind.git@2f04eac452a6d9142dedb957701bdb20125561e4
+mlx>=0.18.1
+nanobind==2.2.0

examples/extensions/setup.py

@@ -13,7 +13,6 @@ if __name__ == "__main__":
         cmdclass={"build_ext": extension.CMakeBuild},
         packages=["mlx_sample_extensions"],
         package_data={"mlx_sample_extensions": ["*.so", "*.dylib", "*.metallib"]},
-        extras_require={"dev": []},
         zip_safe=False,
         python_requires=">=3.8",
     )

mlx/CMakeLists.txt

@@ -1,25 +1,24 @@
 target_sources(
   mlx
-  PRIVATE
-  ${CMAKE_CURRENT_SOURCE_DIR}/allocator.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/array.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/compile.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/device.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/dtype.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/fast.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/fft.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/ops.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/graph_utils.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/primitives.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/random.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/scheduler.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/transforms.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/utils.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/linalg.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/backend/metal/metal.h
-)
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/allocator.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/array.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/compile.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/device.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/dtype.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/einsum.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/fast.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/fft.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/ops.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/graph_utils.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/primitives.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/random.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/scheduler.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/transforms.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/utils.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/linalg.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/backend/metal/metal.h)
 
-if (MLX_BUILD_CPU)
+if(MLX_BUILD_CPU)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backend/common)
 else()
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backend/no_cpu)
@@ -27,17 +26,15 @@ endif()
 
 add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/distributed)
 add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/io)
-if (MLX_BUILD_ACCELERATE)
+if(MLX_BUILD_ACCELERATE)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backend/accelerate)
 elseif(MLX_BUILD_CPU)
   target_sources(
     mlx
-    PRIVATE
-    ${CMAKE_CURRENT_SOURCE_DIR}/backend/common/default_primitives.cpp
-  )
+    PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/backend/common/default_primitives.cpp)
 endif()
 
-if (MLX_BUILD_METAL)
+if(MLX_BUILD_METAL)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backend/metal)
 else()
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backend/no_metal)

mlx/allocator.cpp

@@ -23,11 +23,22 @@ void free(Buffer buffer) {
 }
 
 Buffer CommonAllocator::malloc(size_t size, bool) {
-  return Buffer{std::malloc(size)};
+  void* ptr = std::malloc(size + sizeof(size_t));
+  if (ptr != nullptr) {
+    *static_cast<size_t*>(ptr) = size;
+  }
+  return Buffer{ptr};
 }
 
 void CommonAllocator::free(Buffer buffer) {
-  std::free(buffer.raw_ptr());
+  std::free(buffer.ptr());
+}
+
+size_t CommonAllocator::size(Buffer buffer) const {
+  if (buffer.ptr() == nullptr) {
+    return 0;
+  }
+  return *static_cast<size_t*>(buffer.ptr());
 }
 
 Buffer malloc_or_wait(size_t size) {

mlx/allocator.h

@@ -41,6 +41,7 @@ class Allocator {
  public:
   virtual Buffer malloc(size_t size, bool allow_swap = false) = 0;
   virtual void free(Buffer buffer) = 0;
+  virtual size_t size(Buffer buffer) const = 0;
 
   Allocator() = default;
   Allocator(const Allocator& other) = delete;
@@ -57,6 +58,7 @@ class CommonAllocator : public Allocator {
  public:
   virtual Buffer malloc(size_t size, bool allow_swap = false) override;
   virtual void free(Buffer buffer) override;
+  virtual size_t size(Buffer buffer) const override;
 
  private:
   CommonAllocator() = default;

mlx/array.cpp

@@ -17,6 +17,10 @@ bool in_tracing() {
   return detail::InTracing::in_tracing();
 }
 
+bool retain_graph() {
+  return detail::RetainGraph::retain_graph();
+}
+
 } // namespace
 
 array::array(const std::complex<float>& val, Dtype dtype /* = complex64 */)
@@ -91,18 +95,34 @@ void array::detach() {
   array_desc_->primitive = nullptr;
 }
 
-void array::eval() {
-  // Ensure the array is ready to be read
-  if (status() == Status::scheduled) {
+bool array::is_available() const {
+  if (status() == Status::available) {
+    return true;
+  } else if (status() == Status::evaluated && event().is_signaled()) {
+    set_status(Status::available);
+    return true;
+  }
+  return false;
+}
+
+void array::wait() {
+  if (!is_available()) {
     event().wait();
     set_status(Status::available);
-  } else if (status() == Status::unscheduled) {
+  }
+}
+
+void array::eval() {
+  // Ensure the array is ready to be read
+  if (status() == Status::unscheduled) {
     mlx::core::eval({*this});
+  } else {
+    wait();
   }
 }
 
 bool array::is_tracer() const {
-  return array_desc_->is_tracer && in_tracing();
+  return array_desc_->is_tracer && in_tracing() || retain_graph();
 }
 
 void array::set_data(allocator::Buffer buffer, deleter_t d) {
@@ -171,10 +191,11 @@ array::~array() {
     return;
   }
 
-  // Ignore arrays that will be detached
-  if (status() != array::Status::unscheduled) {
+  // Ignore arrays that might be detached during eval
+  if (status() == array::Status::scheduled) {
     return;
   }
+
   // Break circular reference for non-detached arrays with siblings
   if (auto n = siblings().size(); n > 0) {
     bool do_detach = true;
@@ -206,7 +227,7 @@ void array::ArrayDesc::init() {
     strides[i] = size;
     size *= shape[i];
   }
-  for (auto& in : inputs) {
+  for (const auto& in : inputs) {
     is_tracer |= in.is_tracer();
   }
 }
@@ -231,31 +252,41 @@ array::ArrayDesc::ArrayDesc(
 
 array::ArrayDesc::~ArrayDesc() {
   // When an array description is destroyed it will delete a bunch of arrays
-  // that may also destory their corresponding descriptions and so on and so
+  // that may also destroy their corresponding descriptions and so on and so
   // forth.
   //
   // This calls recursively the destructor and can result in stack overflow, we
   // instead put them in a vector and destroy them one at a time resulting in a
   // max stack depth of 2.
+  if (inputs.empty()) {
+    return;
+  }
+
   std::vector<std::shared_ptr<ArrayDesc>> for_deletion;
 
-  for (array& a : inputs) {
-    if (a.array_desc_.use_count() == 1) {
-      for_deletion.push_back(std::move(a.array_desc_));
+  auto append_deletable_inputs = [&for_deletion](ArrayDesc& ad) {
+    std::unordered_map<std::uintptr_t, array> input_map;
+    for (array& a : ad.inputs) {
+      if (a.array_desc_) {
+        input_map.insert({a.id(), a});
+      }
     }
-  }
+    ad.inputs.clear();
+    for (auto& [_, a] : input_map) {
+      if (a.array_desc_.use_count() <= a.siblings().size() + 1) {
+        for_deletion.push_back(std::move(a.array_desc_));
+      }
+    }
+  };
+
+  append_deletable_inputs(*this);
 
   while (!for_deletion.empty()) {
     // top is going to be deleted at the end of the block *after* the arrays
     // with inputs have been moved into the vector
     auto top = std::move(for_deletion.back());
     for_deletion.pop_back();
-
-    for (array& a : top->inputs) {
-      if (a.array_desc_.use_count() == 1) {
-        for_deletion.push_back(std::move(a.array_desc_));
-      }
-    }
+    append_deletable_inputs(*top);
   }
 }
 

mlx/array.h

@@ -73,32 +73,32 @@ class array {
       this->array_desc_ = other.array_desc_;
     }
     return *this;
-  };
+  }
 
   /** The size of the array's datatype in bytes. */
   size_t itemsize() const {
     return size_of(dtype());
-  };
+  }
 
   /** The number of elements in the array. */
   size_t size() const {
     return array_desc_->size;
-  };
+  }
 
   /** The number of bytes in the array. */
   size_t nbytes() const {
     return size() * itemsize();
-  };
+  }
 
   /** The number of dimensions of the array. */
   size_t ndim() const {
     return array_desc_->shape.size();
-  };
+  }
 
   /** The shape of the array as a vector of integers. */
   const std::vector<int>& shape() const {
     return array_desc_->shape;
-  };
+  }
 
   /**
    *  Get the size of the corresponding dimension.
@@ -107,12 +107,12 @@ class array {
    *  bounds checking. */
   int shape(int dim) const {
     return shape().at(dim < 0 ? dim + ndim() : dim);
-  };
+  }
 
   /** The strides of the array. */
   const std::vector<size_t>& strides() const {
     return array_desc_->strides;
-  };
+  }
 
   /**
    *  Get the stride of the corresponding dimension.
@@ -121,12 +121,12 @@ class array {
    *  bounds checking. */
   size_t strides(int dim) const {
     return strides().at(dim < 0 ? dim + ndim() : dim);
-  };
+  }
 
   /** Get the arrays data type. */
   Dtype dtype() const {
     return array_desc_->dtype;
-  };
+  }
 
   /** Evaluate the array. */
   void eval();
@@ -160,10 +160,10 @@ class array {
 
     friend bool operator==(const ArrayIterator& a, const ArrayIterator& b) {
       return a.arr.id() == b.arr.id() && a.idx == b.idx;
-    };
+    }
     friend bool operator!=(const ArrayIterator& a, const ArrayIterator& b) {
       return !(a == b);
-    };
+    }
 
    private:
     const array& arr;
@@ -209,7 +209,7 @@ class array {
     allocator::Buffer buffer;
     deleter_t d;
     Data(allocator::Buffer buffer, deleter_t d = allocator::free)
-        : buffer(buffer), d(d) {};
+        : buffer(buffer), d(d) {}
     // Not copyable
     Data(const Data& d) = delete;
     Data& operator=(const Data& d) = delete;
@@ -219,33 +219,45 @@ class array {
   };
 
   struct Flags {
-    // True if there are no gaps in the underlying data. Each item
+    // True iff there are no gaps in the underlying data. Each item
     // in the underlying data buffer belongs to at least one index.
+    //
+    // True iff:
+    // prod(shape[i] for i in range(ndim) if strides[i] > 0) == data_size()
     bool contiguous : 1;
 
+    // True iff:
+    // strides[-1] == 1 and
+    // all(strides[i] == (shape[i+1]*strides[i+1]) or shape[i] == 1 for i in
+    // range(ndim - 1))
     bool row_contiguous : 1;
+
+    // True iff:
+    // strides[0] == 1 and
+    // all(strides[i] == (shape[i-1]*strides[i-1]) or shape[i] == 1 for i in
+    // range(1, ndim))
     bool col_contiguous : 1;
   };
 
   /** The array's primitive. */
   Primitive& primitive() const {
     return *(array_desc_->primitive);
-  };
+  }
 
   /** A shared pointer to the array's primitive. */
   std::shared_ptr<Primitive>& primitive_ptr() const {
     return array_desc_->primitive;
-  };
+  }
 
   /** Check if the array has an attached primitive or is a leaf node. */
   bool has_primitive() const {
     return array_desc_->primitive != nullptr;
-  };
+  }
 
   /** The array's inputs. */
   const std::vector<array>& inputs() const {
     return array_desc_->inputs;
-  };
+  }
 
   std::vector<array>& inputs() {
     return array_desc_->inputs;
@@ -259,12 +271,12 @@ class array {
   /** The array's siblings. */
   const std::vector<array>& siblings() const {
     return array_desc_->siblings;
-  };
+  }
 
   /** The array's siblings. */
   std::vector<array>& siblings() {
     return array_desc_->siblings;
-  };
+  }
 
   void set_siblings(std::vector<array> siblings, uint16_t position) {
     array_desc_->siblings = std::move(siblings);
@@ -281,7 +293,7 @@ class array {
     outputs.push_back(*this);
     outputs.insert(outputs.end(), siblings().begin() + idx, siblings().end());
     return outputs;
-  };
+  }
 
   /** Detach the array from the graph. */
   void detach();
@@ -289,19 +301,32 @@ class array {
   /** Get the Flags bit-field. */
   const Flags& flags() const {
     return array_desc_->flags;
-  };
+  }
 
-  /** The size (in elements) of the underlying buffer the array points to. */
+  /** The size (in elements) of the underlying buffer the array points to.
+   *
+   * This can be different than the actual size of the array if the array has
+   * been broadcast or irregularly strided.  If ``first`` is the offset into
+   * the data buffer of the first element of the array (i.e. the offset
+   * corresponding to ``arr[0, 0, ...]``) and last is the offset into the
+   * data buffer of the last element of the array (i.e. the offset
+   * corresponding to ``arr[-1, -1, ...]``) then ``data_size = last - first``.
+   * Note, ``data_size`` is in units of ``item_size`` (not bytes).
+   **/
   size_t data_size() const {
     return array_desc_->data_size;
-  };
+  }
 
   allocator::Buffer& buffer() {
     return array_desc_->data->buffer;
-  };
+  }
   const allocator::Buffer& buffer() const {
     return array_desc_->data->buffer;
-  };
+  }
+
+  size_t buffer_size() const {
+    return allocator::allocator().size(buffer());
+  }
 
   // Return a copy of the shared pointer
   // to the array::Data struct
@@ -312,19 +337,42 @@ class array {
   template <typename T>
   T* data() {
     return static_cast<T*>(array_desc_->data_ptr);
-  };
+  }
 
   template <typename T>
   const T* data() const {
     return static_cast<T*>(array_desc_->data_ptr);
+  }
+
+  enum Status {
+    // The ouptut of a computation which has not been scheduled.
+    // For example, the status of `x` in `auto x = a + b`.
+    unscheduled,
+
+    // The ouptut of a computation which has been scheduled but `eval_*` has
+    // not yet been called on the array's primitive. A possible
+    // status of `x` in `auto x = a + b; eval(x);`
+    scheduled,
+
+    // The array's `eval_*` function has been run, but the computation is not
+    // necessarily complete. The array will have memory allocated and if it is
+    // not a tracer then it will be detached from the graph.
+    evaluated,
+
+    // If the array is the output of a computation then the computation
+    // is complete. Constant arrays are always available (e.g. `array({1, 2,
+    // 3})`)
+    available
   };
 
-  enum Status { unscheduled, scheduled, available };
+  // Check if the array is safe to read.
+  bool is_available() const;
 
-  bool is_available() const {
-    return status() == Status::available;
-  }
-  const Status status() const {
+  // Wait on the array to be available. After this `is_available` returns
+  // `true`.
+  void wait();
+
+  Status status() const {
     return array_desc_->status;
   }
 
@@ -411,8 +459,6 @@ class array {
     void* data_ptr{nullptr};
 
     // The size in elements of the data buffer the array accesses
-    // This can be different than the actual size of the array if it
-    // has been broadcast or irregularly strided.
     size_t data_size;
 
     // Contains useful meta data about the array

mlx/backend/accelerate/CMakeLists.txt

@@ -1,10 +1,8 @@
 target_sources(
   mlx
-  PRIVATE
-  ${CMAKE_CURRENT_SOURCE_DIR}/conv.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/matmul.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/primitives.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/quantized.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/reduce.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/softmax.cpp
-)
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/conv.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/matmul.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/primitives.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/quantized.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/reduce.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/softmax.cpp)

mlx/backend/accelerate/conv.cpp

@@ -1,9 +1,9 @@
-// Copyright © 2023 Apple Inc.
+// Copyright © 2023-2024 Apple Inc.
 
 #include <cassert>
 
+#include <Accelerate/Accelerate.h>
 #include <simd/vector.h>
-#include <vecLib/vDSP.h>
 
 #include "mlx/backend/common/copy.h"
 #include "mlx/primitives.h"

mlx/backend/accelerate/matmul.cpp

@@ -2,8 +2,7 @@
 
 #include <cassert>
 
-#include <vecLib/BNNS/bnns.h>
-#include <vecLib/cblas_new.h>
+#include <Accelerate/Accelerate.h>
 
 #include "mlx/backend/accelerate/utils.h"
 #include "mlx/backend/common/copy.h"

mlx/backend/accelerate/primitives.cpp

@@ -3,8 +3,7 @@
 #include <cassert>
 #include <cmath>
 
-#include <vecLib/vDSP.h>
-#include <vecLib/vForce.h>
+#include <Accelerate/Accelerate.h>
 
 #include "mlx/allocator.h"
 #include "mlx/backend/common/binary.h"
@@ -37,7 +36,7 @@ DEFAULT(Ceil)
 DEFAULT(Concatenate)
 DEFAULT(Conjugate)
 DEFAULT(Copy)
-DEFAULT_MULTI(CustomVJP)
+DEFAULT_MULTI(CustomTransforms)
 DEFAULT_MULTI(Depends)
 DEFAULT_MULTI(DivMod)
 DEFAULT(NumberOfElements)
@@ -51,6 +50,7 @@ DEFAULT(GatherMM)
 DEFAULT(GatherQMM)
 DEFAULT(Greater)
 DEFAULT(GreaterEqual)
+DEFAULT(Hadamard)
 DEFAULT(Less)
 DEFAULT(LessEqual)
 DEFAULT(Load)
@@ -102,7 +102,7 @@ void Add::eval_cpu(const std::vector<array>& inputs, array& out) {
   auto& b = inputs[1];
 
   if (a.dtype() == float32) {
-    binary(
+    binary_op<float>(
         a,
         b,
         out,
@@ -117,7 +117,7 @@ void Add::eval_cpu(const std::vector<array>& inputs, array& out) {
           vDSP_vadd((const float*)a, 1, (const float*)b, 1, (float*)o, 1, n);
         });
   } else if (a.dtype() == int32) {
-    binary(
+    binary_op<int>(
         a,
         b,
         out,
@@ -132,7 +132,7 @@ void Add::eval_cpu(const std::vector<array>& inputs, array& out) {
           vDSP_vaddi((const int*)a, 1, (const int*)b, 1, (int*)o, 1, n);
         });
   } else {
-    binary(a, b, out, [](auto x, auto y) { return x + y; });
+    eval(inputs, out);
   }
 }
 
@@ -287,7 +287,7 @@ void Divide::eval_cpu(const std::vector<array>& inputs, array& out) {
   auto& b = inputs[1];
 
   if (a.dtype() == int32) {
-    binary(
+    binary_op<int>(
         a,
         b,
         out,
@@ -300,7 +300,7 @@ void Divide::eval_cpu(const std::vector<array>& inputs, array& out) {
           vDSP_vdivi((const int*)b, 1, (const int*)a, 1, (int*)o, 1, n);
         });
   } else if (a.dtype() == float32) {
-    binary(
+    binary_op<float>(
         a,
         b,
         out,
@@ -315,7 +315,7 @@ void Divide::eval_cpu(const std::vector<array>& inputs, array& out) {
           vDSP_vdiv((const float*)b, 1, (const float*)a, 1, (float*)o, 1, n);
         });
   } else {
-    binary(a, b, out, [](auto x, auto y) { return x / y; });
+    eval(inputs, out);
   }
 }
 
@@ -326,12 +326,8 @@ void Exp::eval_cpu(const std::vector<array>& inputs, array& out) {
     set_unary_output_data(in, out);
     auto size = in.data_size();
     vvexpf(out.data<float>(), in.data<float>(), reinterpret_cast<int*>(&size));
-  } else if (issubdtype(out.dtype(), inexact)) {
-    unary_fp(in, out, [](auto x) { return std::exp(x); });
   } else {
-    throw std::invalid_argument(
-        "[exp] Cannot exponentiate elements in array"
-        " with non floating point type.");
+    eval(inputs, out);
   }
 }
 
@@ -393,12 +389,8 @@ void Log1p::eval_cpu(const std::vector<array>& inputs, array& out) {
     auto size = in.data_size();
     vvlog1pf(
         out.data<float>(), in.data<float>(), reinterpret_cast<int*>(&size));
-  } else if (issubdtype(out.dtype(), inexact)) {
-    unary_fp(in, out, [](auto x) { return std::log1p(x); });
   } else {
-    throw std::invalid_argument(
-        "[log1p] Cannot compute log of elements in array with"
-        " non floating point type.");
+    eval(inputs, out);
   }
 }
 
@@ -408,7 +400,7 @@ void Multiply::eval_cpu(const std::vector<array>& inputs, array& out) {
   auto& b = inputs[1];
 
   if (a.dtype() == float32) {
-    binary(
+    binary_op<float>(
         a,
         b,
         out,
@@ -423,7 +415,7 @@ void Multiply::eval_cpu(const std::vector<array>& inputs, array& out) {
           vDSP_vmul((const float*)a, 1, (const float*)b, 1, (float*)o, 1, n);
         });
   } else {
-    binary(a, b, out, [](auto x, auto y) { return x * y; });
+    eval(inputs, out);
   }
 }
 
@@ -434,7 +426,7 @@ void Negative::eval_cpu(const std::vector<array>& inputs, array& out) {
     set_unary_output_data(in, out);
     vDSP_vneg(in.data<float>(), 1, out.data<float>(), 1, in.data_size());
   } else {
-    unary(in, out, [](auto x) { return -x; });
+    eval(inputs, out);
   }
 }
 
@@ -521,7 +513,7 @@ void Square::eval_cpu(const std::vector<array>& inputs, array& out) {
     auto size = in.data_size();
     vDSP_vsq(in.data<float>(), 1, out.data<float>(), 1, size);
   } else {
-    unary(in, out, [](auto x) { return x * x; });
+    eval(inputs, out);
   }
 }
 
@@ -547,7 +539,7 @@ void Subtract::eval_cpu(const std::vector<array>& inputs, array& out) {
   auto& b = inputs[1];
 
   if (a.dtype() == float32) {
-    binary(
+    binary_op<float>(
         a,
         b,
         out,
@@ -565,7 +557,7 @@ void Subtract::eval_cpu(const std::vector<array>& inputs, array& out) {
           vDSP_vsub((const float*)b, 1, (const float*)a, 1, (float*)o, 1, n);
         });
   } else if (a.dtype() == int32) {
-    binary(
+    binary_op<int>(
         a,
         b,
         out,
@@ -577,7 +569,7 @@ void Subtract::eval_cpu(const std::vector<array>& inputs, array& out) {
         },
         UseDefaultBinaryOp());
   } else {
-    binary(a, b, out, [](auto x, auto y) { return x - y; });
+    eval(inputs, out);
   }
 }
 

mlx/backend/accelerate/reduce.cpp

@@ -2,8 +2,8 @@
 
 #include <cassert>
 
+#include <Accelerate/Accelerate.h>
 #include <simd/vector.h>
-#include <vecLib/vDSP.h>
 
 #include "mlx/backend/common/reduce.h"
 #include "mlx/primitives.h"

mlx/backend/accelerate/softmax.cpp

@@ -3,7 +3,10 @@
 #include <cassert>
 #include <limits>
 
+#if __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
 #include <arm_neon.h>
+#endif
+
 #include <simd/math.h>
 #include <simd/vector.h>
 
@@ -30,8 +33,8 @@ namespace {
  * Note: The implementation below is a general fast exp. There could be faster
  *       implementations for numbers strictly < 0.
  */
-inline simd_float16 simd_fast_exp(simd_float16 x) {
-  x *= 1.442695; // multiply with log_2(e)
+inline simd_float16 simd_fast_exp(simd_float16 x_init) {
+  auto x = x_init * 1.442695; // multiply with log_2(e)
   simd_float16 ipart, fpart;
   simd_int16 epart;
   x = simd_clamp(x, -80, 80);
@@ -50,28 +53,30 @@ inline simd_float16 simd_fast_exp(simd_float16 x) {
   // bitshifting
   epart = (simd_int(ipart) + 127) << 23;
 
-  return (*(simd_float16*)&epart) * x;
+  // Avoid supressing NaNs
+  simd_int16 eq = (x_init == x_init);
+  return simd_bitselect(x_init, (*(simd_float16*)&epart) * x, eq);
 }
 
+#if __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
 /**
  * The ARM neon equivalent of the fast exp above.
  */
 inline float16x8_t neon_fast_exp(float16x8_t x) {
-  x = vmulq_f16(x, vdupq_n_f16(1.442695)); // multiply with log_2(e)
-  x = vmaxq_f16(x, vdupq_n_f16(-14)); // clamp under with -14
-  x = vminq_f16(x, vdupq_n_f16(14)); // clamp over with 14
+  x = vmulq_f16(x, vdupq_n_f16(float16_t(1.442695f))); // multiply with log_2(e)
+  x = vmaxq_f16(x, vdupq_n_f16(float16_t(-14.f))); // clamp under with -14
+  x = vminq_f16(x, vdupq_n_f16(float16_t(14.f))); // clamp over with 14
 
-  float16x8_t ipart = vrndmq_f16(vaddq_f16(x, vdupq_n_f16(0.5)));
+  float16x8_t ipart = vrndmq_f16(vaddq_f16(x, vdupq_n_f16(float16_t(0.5f))));
   float16x8_t fpart = vsubq_f16(x, ipart);
 
-  x = vdupq_n_f16(1.535336188319500e-4f);
-  x = vfmaq_f16(vdupq_n_f16(1.339887440266574e-3f), x, fpart);
-  x = vfmaq_f16(vdupq_n_f16(1.339887440266574e-3f), x, fpart);
-  x = vfmaq_f16(vdupq_n_f16(9.618437357674640e-3f), x, fpart);
-  x = vfmaq_f16(vdupq_n_f16(5.550332471162809e-2f), x, fpart);
-  x = vfmaq_f16(vdupq_n_f16(2.402264791363012e-1f), x, fpart);
-  x = vfmaq_f16(vdupq_n_f16(6.931472028550421e-1f), x, fpart);
-  x = vfmaq_f16(vdupq_n_f16(1.000000000000000f), x, fpart);
+  x = vdupq_n_f16(float16_t(1.535336188319500e-4f));
+  x = vfmaq_f16(vdupq_n_f16(float16_t(1.339887440266574e-3f)), x, fpart);
+  x = vfmaq_f16(vdupq_n_f16(float16_t(9.618437357674640e-3f)), x, fpart);
+  x = vfmaq_f16(vdupq_n_f16(float16_t(5.550332471162809e-2f)), x, fpart);
+  x = vfmaq_f16(vdupq_n_f16(float16_t(2.402264791363012e-1f)), x, fpart);
+  x = vfmaq_f16(vdupq_n_f16(float16_t(6.931472028550421e-1f)), x, fpart);
+  x = vfmaq_f16(vdupq_n_f16(float16_t(1.000000000000000f)), x, fpart);
 
   // generate 2**ipart in the floating point representation using integer
   // bitshifting
@@ -107,53 +112,6 @@ inline float16_t neon_reduce_add(float16x8_t x) {
   return vget_lane_f16(y, 0);
 }
 
-template <typename T, typename VT>
-struct AccelerateSimdOps {
-  VT init(T a) {
-    return a;
-  }
-
-  VT load(const T* a) {
-    return *(VT*)a;
-  }
-
-  void store(T* dst, VT x) {
-    *(VT*)dst = x;
-  }
-
-  VT max(VT a, VT b) {
-    return simd_max(a, b);
-  };
-
-  VT exp(VT x) {
-    return simd_fast_exp(x);
-  }
-
-  VT add(VT a, VT b) {
-    return a + b;
-  }
-
-  VT sub(VT a, T b) {
-    return a - b;
-  }
-
-  VT mul(VT a, VT b) {
-    return a * b;
-  }
-
-  VT mul(VT a, T b) {
-    return a * b;
-  }
-
-  T reduce_max(VT x) {
-    return simd_reduce_max(x);
-  }
-
-  T reduce_add(VT x) {
-    return simd_reduce_add(x);
-  }
-};
-
 template <typename T, typename VT>
 struct NeonFp16SimdOps {
   VT init(T a) {
@@ -170,7 +128,7 @@ struct NeonFp16SimdOps {
 
   VT max(VT a, VT b) {
     return vmaxq_f16(a, b);
-  };
+  }
 
   VT exp(VT x) {
     return neon_fast_exp(x);
@@ -201,6 +159,55 @@ struct NeonFp16SimdOps {
   }
 };
 
+#endif // __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
+
+template <typename T, typename VT>
+struct AccelerateSimdOps {
+  VT init(T a) {
+    return a;
+  }
+
+  VT load(const T* a) {
+    return *(VT*)a;
+  }
+
+  void store(T* dst, VT x) {
+    *(VT*)dst = x;
+  }
+
+  VT max(VT a, VT b) {
+    return simd_max(a, b);
+  }
+
+  VT exp(VT x) {
+    return simd_fast_exp(x);
+  }
+
+  VT add(VT a, VT b) {
+    return a + b;
+  }
+
+  VT sub(VT a, T b) {
+    return a - b;
+  }
+
+  VT mul(VT a, VT b) {
+    return a * b;
+  }
+
+  VT mul(VT a, T b) {
+    return a * b;
+  }
+
+  T reduce_max(VT x) {
+    return simd_reduce_max(x);
+  }
+
+  T reduce_add(VT x) {
+    return simd_reduce_add(x);
+  }
+};
+
 template <typename T, typename AccT, typename VT, typename Ops, int N>
 void softmax(const array& in, array& out) {
   Ops ops;
@@ -362,12 +369,16 @@ void Softmax::eval_cpu(const std::vector<array>& inputs, array& out) {
             AccelerateSimdOps<float, simd_float16>,
             16>(in, out);
       } else {
+#if __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
         softmax<
             float16_t,
             float16_t,
             float16x8_t,
             NeonFp16SimdOps<float16_t, float16x8_t>,
             8>(in, out);
+#else // __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
+        eval(inputs, out); // Redirect to common backend for consistency
+#endif // __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
       }
       break;
     case bfloat16:

mlx/backend/accelerate/utils.h

@@ -1,8 +1,8 @@
-// Copyright © 2023 Apple Inc.
+// Copyright © 2023-2024 Apple Inc.
 
 #pragma once
 
-#include <vecLib/BNNS/bnns.h>
+#include <Accelerate/Accelerate.h>
 #include "mlx/dtype.h"
 
 namespace mlx::core {

mlx/backend/common/CMakeLists.txt

@@ -1,5 +1,4 @@
-
-if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
   set(COMPILER ${CMAKE_C_COMPILER})
   set(CLANG TRUE)
 else()
@@ -7,70 +6,56 @@ else()
 endif()
 
 add_custom_command(
-    OUTPUT  compiled_preamble.cpp
-    COMMAND /bin/bash
-              ${CMAKE_CURRENT_SOURCE_DIR}/make_compiled_preamble.sh
-              ${CMAKE_CURRENT_BINARY_DIR}/compiled_preamble.cpp
-              ${COMPILER}
-              ${PROJECT_SOURCE_DIR}
-              ${CLANG}
+  OUTPUT compiled_preamble.cpp
+  COMMAND
+    /bin/bash ${CMAKE_CURRENT_SOURCE_DIR}/make_compiled_preamble.sh
+    ${CMAKE_CURRENT_BINARY_DIR}/compiled_preamble.cpp ${COMPILER}
+    ${PROJECT_SOURCE_DIR} ${CLANG}
+  DEPENDS make_compiled_preamble.sh
+          compiled_preamble.h
+          ${PROJECT_SOURCE_DIR}/mlx/types/half_types.h
+          ${PROJECT_SOURCE_DIR}/mlx/types/fp16.h
+          ${PROJECT_SOURCE_DIR}/mlx/types/bf16.h
+          ${PROJECT_SOURCE_DIR}/mlx/types/complex.h
+          ops.h)
 
-    DEPENDS make_compiled_preamble.sh
-            compiled_preamble.h
-            ${PROJECT_SOURCE_DIR}/mlx/types/half_types.h
-            ${PROJECT_SOURCE_DIR}/mlx/types/fp16.h
-            ${PROJECT_SOURCE_DIR}/mlx/types/bf16.h
-            ${PROJECT_SOURCE_DIR}/mlx/types/complex.h
-            ops.h
-)
-
-add_custom_target(
-  cpu_compiled_preamble
-  DEPENDS compiled_preamble.cpp
-)
+add_custom_target(cpu_compiled_preamble DEPENDS compiled_preamble.cpp)
 
 add_dependencies(mlx cpu_compiled_preamble)
 
 target_sources(
   mlx
-  PRIVATE
-  ${CMAKE_CURRENT_SOURCE_DIR}/arg_reduce.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/binary.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/compiled.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/common.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/conv.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/copy.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/erf.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/fft.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/masked_mm.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/primitives.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/quantized.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/reduce.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/scan.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/select.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/slicing.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/softmax.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/sort.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/threefry.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/indexing.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/load.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/qrf.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/svd.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/inverse.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/cholesky.cpp
-  ${CMAKE_CURRENT_BINARY_DIR}/compiled_preamble.cpp
-)
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/arg_reduce.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/binary.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/compiled.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/common.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/conv.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/copy.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/erf.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/fft.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/hadamard.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/masked_mm.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/primitives.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/quantized.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/reduce.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/reduce_utils.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/scan.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/select.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/slicing.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/softmax.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/sort.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/threefry.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/indexing.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/load.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/qrf.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/svd.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/inverse.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/cholesky.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/utils.cpp
+          ${CMAKE_CURRENT_BINARY_DIR}/compiled_preamble.cpp)
 
-if (IOS)
-  target_sources(
-    mlx
-    PRIVATE
-    ${CMAKE_CURRENT_SOURCE_DIR}/compiled_nocpu.cpp
-  )
+if(IOS)
+  target_sources(mlx PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/compiled_nocpu.cpp)
 else()
-  target_sources(
-    mlx
-    PRIVATE
-    ${CMAKE_CURRENT_SOURCE_DIR}/compiled_cpu.cpp
-  )
+  target_sources(mlx PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/compiled_cpu.cpp)
 endif()

mlx/backend/common/binary.cpp

@@ -196,6 +196,20 @@ void LogAddExp::eval(const std::vector<array>& inputs, array& out) {
   }
 }
 
+void LogicalAnd::eval(const std::vector<array>& inputs, array& out) {
+  assert(inputs.size() == 2); // LogicalAnd requires two input arrays
+  auto& in1 = inputs[0];
+  auto& in2 = inputs[1];
+  binary(in1, in2, out, detail::LogicalAnd());
+}
+
+void LogicalOr::eval(const std::vector<array>& inputs, array& out) {
+  assert(inputs.size() == 2); // LogicalOr requires two input arrays
+  auto& in1 = inputs[0];
+  auto& in2 = inputs[1];
+  binary(in1, in2, out, detail::LogicalOr());
+}
+
 void Maximum::eval(const std::vector<array>& inputs, array& out) {
   assert(inputs.size() == 2);
   auto& a = inputs[0];

mlx/backend/common/binary.h

@@ -43,13 +43,15 @@ void set_binary_op_output_data(
     array& out,
     BinaryOpType bopt,
     bool donate_with_move = false) {
+  bool b_donatable = is_donatable(b, out);
+  bool a_donatable = is_donatable(a, out);
   switch (bopt) {
     case BinaryOpType::ScalarScalar:
       out.set_data(
           allocator::malloc_or_wait(out.itemsize()), 1, a.strides(), a.flags());
       break;
     case BinaryOpType::ScalarVector:
-      if (b.is_donatable() && b.itemsize() == out.itemsize()) {
+      if (b_donatable) {
         if (donate_with_move) {
           out.move_shared_buffer(b);
         } else {
@@ -64,7 +66,7 @@ void set_binary_op_output_data(
       }
       break;
     case BinaryOpType::VectorScalar:
-      if (a.is_donatable() && a.itemsize() == out.itemsize()) {
+      if (a_donatable) {
         if (donate_with_move) {
           out.move_shared_buffer(a);
         } else {
@@ -79,13 +81,13 @@ void set_binary_op_output_data(
       }
       break;
     case BinaryOpType::VectorVector:
-      if (a.is_donatable() && a.itemsize() == out.itemsize()) {
+      if (a_donatable) {
         if (donate_with_move) {
           out.move_shared_buffer(a);
         } else {
           out.copy_shared_buffer(a);
         }
-      } else if (b.is_donatable() && b.itemsize() == out.itemsize()) {
+      } else if (b_donatable) {
         if (donate_with_move) {
           out.move_shared_buffer(b);
         } else {
@@ -100,16 +102,14 @@ void set_binary_op_output_data(
       }
       break;
     case BinaryOpType::General:
-      if (a.is_donatable() && a.flags().row_contiguous &&
-          a.itemsize() == out.itemsize() && a.size() == out.size()) {
+      if (a_donatable && a.flags().row_contiguous && a.size() == out.size()) {
         if (donate_with_move) {
           out.move_shared_buffer(a);
         } else {
           out.copy_shared_buffer(a);
         }
       } else if (
-          b.is_donatable() && b.flags().row_contiguous &&
-          b.itemsize() == out.itemsize() && b.size() == out.size()) {
+          b_donatable && b.flags().row_contiguous && b.size() == out.size()) {
         if (donate_with_move) {
           out.move_shared_buffer(b);
         } else {
@@ -122,19 +122,7 @@ void set_binary_op_output_data(
   }
 }
 
-struct UseDefaultBinaryOp {
-  template <typename T, typename U>
-  void operator()(const T* a, const T* b, U* dst, int size) {
-    // Should we throw? This should normally never be called.
-    assert(false);
-  }
-
-  template <typename T, typename U>
-  void operator()(const T* a, const T* b, U* dst_a, U* dst_b, int size) {
-    // Should we throw? This should normally never be called.
-    assert(false);
-  }
-};
+struct UseDefaultBinaryOp {};
 
 template <typename T, typename U, typename Op>
 struct DefaultVectorScalar {
@@ -150,18 +138,6 @@ struct DefaultVectorScalar {
       a++;
     }
   }
-
-  void operator()(const T* a, const T* b, U* dst_a, U* dst_b, int size) {
-    T scalar = *b;
-    while (size-- > 0) {
-      auto dst = op(*a, scalar);
-      *dst_a = dst.first;
-      *dst_b = dst.second;
-      dst_a++;
-      dst_b++;
-      a++;
-    }
-  }
 };
 
 template <typename T, typename U, typename Op>
@@ -178,18 +154,6 @@ struct DefaultScalarVector {
       b++;
     }
   }
-
-  void operator()(const T* a, const T* b, U* dst_a, U* dst_b, int size) {
-    T scalar = *a;
-    while (size-- > 0) {
-      auto dst = op(scalar, *b);
-      *dst_a = dst.first;
-      *dst_b = dst.second;
-      dst_a++;
-      dst_b++;
-      b++;
-    }
-  }
 };
 
 template <typename T, typename U, typename Op>
@@ -206,204 +170,110 @@ struct DefaultVectorVector {
       b++;
     }
   }
-
-  void operator()(const T* a, const T* b, U* dst_a, U* dst_b, int size) {
-    while (size-- > 0) {
-      auto dst = op(*a, *b);
-      *dst_a = dst.first;
-      *dst_b = dst.second;
-      dst_a++;
-      dst_b++;
-      a++;
-      b++;
-    }
-  }
 };
 
-template <typename T, typename U, typename Op>
-void binary_op_dims1(const array& a, const array& b, array& out, Op op) {
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst = out.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  for (size_t i = 0; i < out.size(); ++i) {
-    dst[i] = op(a_ptr[a_idx], b_ptr[b_idx]);
-    a_idx += a.strides()[0];
-    b_idx += b.strides()[0];
-  }
-}
-
-template <typename T, typename U, typename Op>
-void binary_op_dims1(
-    const array& a,
-    const array& b,
-    array& out,
+template <typename T, typename U, typename Op, int D, bool Strided>
+void binary_op_dims(
+    const T* a,
+    const T* b,
+    U* out,
     Op op,
-    int stride) {
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst = out.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; i++) {
-    op(a_ptr + a_idx, b_ptr + b_idx, dst, stride);
-    a_idx += a.strides()[0];
-    b_idx += b.strides()[0];
-    dst += stride;
-  }
-}
+    const std::vector<int>& shape,
+    const std::vector<size_t>& a_strides,
+    const std::vector<size_t>& b_strides,
+    const std::vector<size_t>& out_strides,
+    int axis) {
+  auto stride_a = a_strides[axis];
+  auto stride_b = b_strides[axis];
+  auto stride_out = out_strides[axis];
+  auto N = shape[axis];
 
-template <typename T, typename U, typename Op>
-void binary_op_dims2(const array& a, const array& b, array& out, Op op) {
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst = out.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  size_t out_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; ++i) {
-    for (size_t j = 0; j < a.shape()[1]; ++j) {
-      dst[out_idx++] = op(a_ptr[a_idx], b_ptr[b_idx]);
-      a_idx += a.strides()[1];
-      b_idx += b.strides()[1];
-    }
-    a_idx += a.strides()[0] - a.strides()[1] * a.shape()[1];
-    b_idx += b.strides()[0] - b.strides()[1] * b.shape()[1];
-  }
-}
-
-template <typename T, typename U, typename Op>
-void binary_op_dims2(
-    const array& a,
-    const array& b,
-    array& out,
-    Op op,
-    int stride) {
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst = out.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; ++i) {
-    for (size_t j = 0; j < a.shape()[1]; ++j) {
-      op(a_ptr + a_idx, b_ptr + b_idx, dst, stride);
-      a_idx += a.strides()[1];
-      b_idx += b.strides()[1];
-      dst += stride;
-    }
-    a_idx += a.strides()[0] - a.strides()[1] * a.shape()[1];
-    b_idx += b.strides()[0] - b.strides()[1] * b.shape()[1];
-  }
-}
-
-template <typename T, typename U, typename Op>
-void binary_op_dims3(const array& a, const array& b, array& out, Op op) {
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst = out.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  size_t out_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; ++i) {
-    for (size_t j = 0; j < a.shape()[1]; ++j) {
-      for (size_t k = 0; k < a.shape()[2]; ++k) {
-        dst[out_idx++] = op(a_ptr[a_idx], b_ptr[b_idx]);
-        a_idx += a.strides()[2];
-        b_idx += b.strides()[2];
+  for (int i = 0; i < N; i++) {
+    if constexpr (D > 1) {
+      binary_op_dims<T, U, Op, D - 1, Strided>(
+          a, b, out, op, shape, a_strides, b_strides, out_strides, axis + 1);
+    } else {
+      if constexpr (Strided) {
+        op(a, b, out, stride_out);
+      } else {
+        *out = op(*a, *b);
       }
-      a_idx += a.strides()[1] - a.strides()[2] * a.shape()[2];
-      b_idx += b.strides()[1] - b.strides()[2] * b.shape()[2];
     }
-    a_idx += a.strides()[0] - a.strides()[1] * a.shape()[1];
-    b_idx += b.strides()[0] - b.strides()[1] * b.shape()[1];
+    out += stride_out;
+    a += stride_a;
+    b += stride_b;
   }
 }
 
-template <typename T, typename U, typename Op>
-void binary_op_dims4(const array& a, const array& b, array& out, Op op) {
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst = out.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  size_t out_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; ++i) {
-    for (size_t j = 0; j < a.shape()[1]; ++j) {
-      for (size_t k = 0; k < a.shape()[2]; ++k) {
-        for (size_t ii = 0; ii < a.shape()[3]; ++ii) {
-          dst[out_idx++] = op(a_ptr[a_idx], b_ptr[b_idx]);
-          a_idx += a.strides()[3];
-          b_idx += b.strides()[3];
-        }
-        a_idx += a.strides()[2] - a.strides()[3] * a.shape()[3];
-        b_idx += b.strides()[2] - b.strides()[3] * b.shape()[3];
-      }
-      a_idx += a.strides()[1] - a.strides()[2] * a.shape()[2];
-      b_idx += b.strides()[1] - b.strides()[2] * b.shape()[2];
-    }
-    a_idx += a.strides()[0] - a.strides()[1] * a.shape()[1];
-    b_idx += b.strides()[0] - b.strides()[1] * b.shape()[1];
-  }
-}
-
-template <typename T, typename U, typename Op>
-void binary_op_dispatch_dims(
-    const array& a,
-    const array& b,
-    array& out,
-    Op op) {
-  switch (out.ndim()) {
-    case 1:
-      binary_op_dims1<T, U, Op>(a, b, out, op);
-      return;
-    case 2:
-      binary_op_dims2<T, U, Op>(a, b, out, op);
-      return;
-    case 3:
-      binary_op_dims3<T, U, Op>(a, b, out, op);
-      return;
-    case 4:
-      binary_op_dims4<T, U, Op>(a, b, out, op);
-      return;
-  }
-
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst = out.data<U>();
-  for (size_t i = 0; i < out.size(); i++) {
-    int a_idx = elem_to_loc(i, a.shape(), a.strides());
-    int b_idx = elem_to_loc(i, b.shape(), b.strides());
-    dst[i] = op(a_ptr[a_idx], b_ptr[b_idx]);
-  }
-}
-
-template <typename T, typename U, typename Op>
+template <typename T, typename U, bool Strided, typename Op>
 void binary_op_dispatch_dims(
     const array& a,
     const array& b,
     array& out,
     Op op,
     int dim,
-    int stride) {
-  // Number of dimensions to loop over for vectorized ops
+    const std::vector<int>& shape,
+    const std::vector<size_t>& a_strides,
+    const std::vector<size_t>& b_strides,
+    const std::vector<size_t>& out_strides) {
+  const T* a_ptr = a.data<T>();
+  const T* b_ptr = b.data<T>();
+  U* out_ptr = out.data<U>();
   switch (dim) {
     case 1:
-      binary_op_dims1<T, U, Op>(a, b, out, op, stride);
+      binary_op_dims<T, U, Op, 1, Strided>(
+          a_ptr,
+          b_ptr,
+          out_ptr,
+          op,
+          shape,
+          a_strides,
+          b_strides,
+          out_strides,
+          0);
       return;
     case 2:
-      binary_op_dims2<T, U, Op>(a, b, out, op, stride);
+      binary_op_dims<T, U, Op, 2, Strided>(
+          a_ptr,
+          b_ptr,
+          out_ptr,
+          op,
+          shape,
+          a_strides,
+          b_strides,
+          out_strides,
+          0);
+      return;
+    case 3:
+      binary_op_dims<T, U, Op, 3, Strided>(
+          a_ptr,
+          b_ptr,
+          out_ptr,
+          op,
+          shape,
+          a_strides,
+          b_strides,
+          out_strides,
+          0);
       return;
   }
 
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst = out.data<U>();
-  for (size_t i = 0; i < out.size(); i += stride) {
-    int a_idx = elem_to_loc(i, a.shape(), a.strides());
-    int b_idx = elem_to_loc(i, b.shape(), b.strides());
-    op(a_ptr + a_idx, b_ptr + b_idx, dst, stride);
-    dst += stride;
+  ContiguousIterator<size_t> a_it(shape, a_strides, dim - 3);
+  ContiguousIterator<size_t> b_it(shape, b_strides, dim - 3);
+  size_t stride = out_strides[dim - 4];
+  for (size_t elem = 0; elem < a.size(); elem += stride) {
+    binary_op_dims<T, U, Op, 3, Strided>(
+        a_ptr + a_it.loc,
+        b_ptr + b_it.loc,
+        out_ptr + elem,
+        op,
+        shape,
+        a_strides,
+        b_strides,
+        out_strides,
+        dim - 3);
+    a_it.step();
+    b_it.step();
   }
 }
 
@@ -450,29 +320,33 @@ void binary_op(
   }
 
   // General computation so let's try to optimize
+  auto [new_shape, new_strides] = collapse_contiguous_dims(
+      a.shape(), {a.strides(), b.strides(), out.strides()});
+  const auto& a_strides = new_strides[0];
+  const auto& b_strides = new_strides[1];
+  const auto& strides = new_strides[2];
 
   // Get the left-most dim such that the array is row contiguous after
-  auto& strides = out.strides();
-  auto leftmost_rc_dim = [&strides](const array& arr) {
-    int d = arr.ndim() - 1;
-    for (; d >= 0 && arr.strides()[d] == strides[d]; d--) {
+  auto leftmost_rc_dim = [&strides](const std::vector<size_t>& arr_strides) {
+    int d = arr_strides.size() - 1;
+    for (; d >= 0 && arr_strides[d] == strides[d]; d--) {
     }
     return d + 1;
   };
-  auto a_rc_dim = leftmost_rc_dim(a);
-  auto b_rc_dim = leftmost_rc_dim(b);
+  auto a_rc_dim = leftmost_rc_dim(a_strides);
+  auto b_rc_dim = leftmost_rc_dim(b_strides);
 
   // Get the left-most dim such that the array is a broadcasted "scalar" after
-  auto leftmost_s_dim = [](const array& arr) {
-    int d = arr.ndim() - 1;
-    for (; d >= 0 && arr.strides()[d] == 0; d--) {
+  auto leftmost_s_dim = [](const std::vector<size_t>& arr_strides) {
+    int d = arr_strides.size() - 1;
+    for (; d >= 0 && arr_strides[d] == 0; d--) {
     }
     return d + 1;
   };
-  auto a_s_dim = leftmost_s_dim(a);
-  auto b_s_dim = leftmost_s_dim(b);
+  auto a_s_dim = leftmost_s_dim(a_strides);
+  auto b_s_dim = leftmost_s_dim(b_strides);
 
-  auto ndim = out.ndim();
+  auto ndim = new_shape.size();
 
   // Case 1: LxM and FxM where L and F are broadcastable and M is row contiguous
   int dim = ndim;
@@ -494,27 +368,27 @@ void binary_op(
   // Can be sure dim > 0 since otherwise we would have used one of the fully
   // contiguous methods above. Except for the case that the flags do not
   // correspond to the underlying contiguity.
-  size_t stride;
   if (dim == 0 || strides[dim - 1] < 16) {
-    stride = 1;
     bopt = BinaryOpType::General;
     dim = ndim;
-  } else {
-    stride = strides[dim - 1];
   }
 
   switch (bopt) {
     case BinaryOpType::VectorVector:
-      binary_op_dispatch_dims<T, U>(a, b, out, opvv, dim, stride);
+      binary_op_dispatch_dims<T, U, true>(
+          a, b, out, opvv, dim, new_shape, a_strides, b_strides, strides);
       break;
     case BinaryOpType::VectorScalar:
-      binary_op_dispatch_dims<T, U>(a, b, out, opvs, dim, stride);
+      binary_op_dispatch_dims<T, U, true>(
+          a, b, out, opvs, dim, new_shape, a_strides, b_strides, strides);
       break;
     case BinaryOpType::ScalarVector:
-      binary_op_dispatch_dims<T, U>(a, b, out, opsv, dim, stride);
+      binary_op_dispatch_dims<T, U, true>(
+          a, b, out, opsv, dim, new_shape, a_strides, b_strides, strides);
       break;
     default:
-      binary_op_dispatch_dims<T, U>(a, b, out, op);
+      binary_op_dispatch_dims<T, U, false>(
+          a, b, out, op, dim, new_shape, a_strides, b_strides, strides);
       break;
   }
 }
@@ -531,9 +405,9 @@ void binary_op(
   // TODO: The following mess of constexpr evaluations can probably be achieved
   //       with template specializations and overloading. Would it be simpler?
 
-  if (std::is_same<decltype(opsv), UseDefaultBinaryOp>::value) {
-    if (std::is_same<decltype(opvs), UseDefaultBinaryOp>::value) {
-      if (std::is_same<decltype(opvv), UseDefaultBinaryOp>::value) {
+  if constexpr (std::is_same<decltype(opsv), UseDefaultBinaryOp>::value) {
+    if constexpr (std::is_same<decltype(opvs), UseDefaultBinaryOp>::value) {
+      if constexpr (std::is_same<decltype(opvv), UseDefaultBinaryOp>::value) {
         // All ops are UseDefaultBinaryOp (why oh why would someone call that?)
         binary_op<T, T>(
             a,
@@ -554,7 +428,8 @@ void binary_op(
             DefaultVectorScalar<T, T, Op>(op),
             opvv);
       }
-    } else if (std::is_same<decltype(opvv), UseDefaultBinaryOp>::value) {
+    } else if constexpr (std::is_same<decltype(opvv), UseDefaultBinaryOp>::
+                             value) {
       // opsv and opvv were UseDefaultBinaryOp
       binary_op<T, T>(
           a,
@@ -569,7 +444,8 @@ void binary_op(
       binary_op<T, T>(
           a, b, out, op, DefaultScalarVector<T, T, Op>(op), opvs, opvv);
     }
-  } else if (std::is_same<decltype(opvs), UseDefaultBinaryOp>::value) {
+  } else if constexpr (std::is_same<decltype(opvs), UseDefaultBinaryOp>::
+                           value) {
     if (std::is_same<decltype(opvv), UseDefaultBinaryOp>::value) {
       // opvs and opvv were UseDefaultBinaryOp
       binary_op<T, T>(
@@ -585,7 +461,8 @@ void binary_op(
       binary_op<T, T>(
           a, b, out, op, opsv, DefaultVectorScalar<T, T, Op>(op), opvv);
     }
-  } else if (std::is_same<decltype(opvv), UseDefaultBinaryOp>::value) {
+  } else if constexpr (std::is_same<decltype(opvv), UseDefaultBinaryOp>::
+                           value) {
     // opvv was UseDefaultBinaryOp
     binary_op<T, T>(
         a, b, out, op, opsv, opvs, DefaultVectorVector<T, T, Op>(op));

mlx/backend/common/binary_two.h

@@ -9,168 +9,43 @@ namespace mlx::core {
 
 namespace {
 
-template <typename T, typename U, typename Op>
-void binary_op_dims1(
-    const array& a,
-    const array& b,
-    array& out_a,
-    array& out_b,
-    Op op) {
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst_a = out_a.data<U>();
-  U* dst_b = out_b.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  for (size_t i = 0; i < out_a.size(); ++i) {
-    auto dst = op(a_ptr[a_idx], b_ptr[b_idx]);
-    dst_a[i] = dst.first;
-    dst_b[i] = dst.second;
-    a_idx += a.strides()[0];
-    b_idx += b.strides()[0];
-  }
-}
-
-template <typename T, typename U, typename Op>
-void binary_op_dims1(
-    const array& a,
-    const array& b,
-    array& out_a,
-    array& out_b,
+template <typename T, typename U, typename Op, int D>
+void binary_op_dims(
+    const T* a,
+    const T* b,
+    U* out_a,
+    U* out_b,
     Op op,
-    int stride) {
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst_a = out_a.data<U>();
-  U* dst_b = out_b.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; i++) {
-    op(a_ptr + a_idx, b_ptr + b_idx, dst_a, dst_b, stride);
-    a_idx += a.strides()[0];
-    b_idx += b.strides()[0];
-    dst_a += stride;
-    dst_b += stride;
-  }
-}
+    const std::vector<int>& shape,
+    const std::vector<size_t>& a_strides,
+    const std::vector<size_t>& b_strides,
+    const std::vector<size_t>& out_strides,
+    int axis) {
+  auto stride_a = a_strides[axis];
+  auto stride_b = b_strides[axis];
+  auto stride_out = out_strides[axis];
+  auto N = shape[axis];
 
-template <typename T, typename U, typename Op>
-void binary_op_dims2(
-    const array& a,
-    const array& b,
-    array& out_a,
-    array& out_b,
-    Op op) {
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst_a = out_a.data<U>();
-  U* dst_b = out_b.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  size_t out_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; ++i) {
-    for (size_t j = 0; j < a.shape()[1]; ++j) {
-      auto dst = op(a_ptr[a_idx], b_ptr[b_idx]);
-      dst_a[out_idx] = dst.first;
-      dst_b[out_idx++] = dst.second;
-      a_idx += a.strides()[1];
-      b_idx += b.strides()[1];
+  for (int i = 0; i < N; i++) {
+    if constexpr (D > 1) {
+      binary_op_dims<T, U, Op, D - 1>(
+          a,
+          b,
+          out_a,
+          out_b,
+          op,
+          shape,
+          a_strides,
+          b_strides,
+          out_strides,
+          axis + 1);
+    } else {
+      std::tie(*out_a, *out_b) = op(*a, *b);
     }
-    a_idx += a.strides()[0] - a.strides()[1] * a.shape()[1];
-    b_idx += b.strides()[0] - b.strides()[1] * b.shape()[1];
-  }
-}
-
-template <typename T, typename U, typename Op>
-void binary_op_dims2(
-    const array& a,
-    const array& b,
-    array& out_a,
-    array& out_b,
-    Op op,
-    int stride) {
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst_a = out_a.data<U>();
-  U* dst_b = out_b.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; ++i) {
-    for (size_t j = 0; j < a.shape()[1]; ++j) {
-      op(a_ptr + a_idx, b_ptr + b_idx, dst_a, dst_b, stride);
-      a_idx += a.strides()[1];
-      b_idx += b.strides()[1];
-      dst_a += stride;
-      dst_b += stride;
-    }
-    a_idx += a.strides()[0] - a.strides()[1] * a.shape()[1];
-    b_idx += b.strides()[0] - b.strides()[1] * b.shape()[1];
-  }
-}
-
-template <typename T, typename U, typename Op>
-void binary_op_dims3(
-    const array& a,
-    const array& b,
-    array& out_a,
-    array& out_b,
-    Op op) {
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst_a = out_a.data<U>();
-  U* dst_b = out_b.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  size_t out_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; ++i) {
-    for (size_t j = 0; j < a.shape()[1]; ++j) {
-      for (size_t k = 0; k < a.shape()[2]; ++k) {
-        auto dst = op(a_ptr[a_idx], b_ptr[b_idx]);
-        dst_a[out_idx] = dst.first;
-        dst_b[out_idx++] = dst.second;
-        a_idx += a.strides()[2];
-        b_idx += b.strides()[2];
-      }
-      a_idx += a.strides()[1] - a.strides()[2] * a.shape()[2];
-      b_idx += b.strides()[1] - b.strides()[2] * b.shape()[2];
-    }
-    a_idx += a.strides()[0] - a.strides()[1] * a.shape()[1];
-    b_idx += b.strides()[0] - b.strides()[1] * b.shape()[1];
-  }
-}
-
-template <typename T, typename U, typename Op>
-void binary_op_dims4(
-    const array& a,
-    const array& b,
-    array& out_a,
-    array& out_b,
-    Op op) {
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst_a = out_a.data<U>();
-  U* dst_b = out_b.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  size_t out_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; ++i) {
-    for (size_t j = 0; j < a.shape()[1]; ++j) {
-      for (size_t k = 0; k < a.shape()[2]; ++k) {
-        for (size_t ii = 0; ii < a.shape()[3]; ++ii) {
-          auto dst = op(a_ptr[a_idx], b_ptr[b_idx]);
-          dst_a[out_idx] = dst.first;
-          dst_b[out_idx++] = dst.second;
-          a_idx += a.strides()[3];
-          b_idx += b.strides()[3];
-        }
-        a_idx += a.strides()[2] - a.strides()[3] * a.shape()[3];
-        b_idx += b.strides()[2] - b.strides()[3] * b.shape()[3];
-      }
-      a_idx += a.strides()[1] - a.strides()[2] * a.shape()[2];
-      b_idx += b.strides()[1] - b.strides()[2] * b.shape()[2];
-    }
-    a_idx += a.strides()[0] - a.strides()[1] * a.shape()[1];
-    b_idx += b.strides()[0] - b.strides()[1] * b.shape()[1];
+    a += stride_a;
+    b += stride_b;
+    out_a += stride_out;
+    out_b += stride_out;
   }
 }
 
@@ -181,352 +56,160 @@ void binary_op_dispatch_dims(
     array& out_a,
     array& out_b,
     Op op) {
-  switch (out_a.ndim()) {
+  auto [shape, strides] = collapse_contiguous_dims(
+      a.shape(), {a.strides(), b.strides(), out_a.strides()});
+  const auto& a_strides = strides[0];
+  const auto& b_strides = strides[1];
+  const auto& out_strides = strides[2];
+  const T* a_ptr = a.data<T>();
+  const T* b_ptr = b.data<T>();
+  U* out_a_ptr = out_a.data<U>();
+  U* out_b_ptr = out_b.data<U>();
+
+  int ndim = shape.size();
+  switch (ndim) {
     case 1:
-      binary_op_dims1<T, U, Op>(a, b, out_a, out_b, op);
+      binary_op_dims<T, U, Op, 1>(
+          a_ptr,
+          b_ptr,
+          out_a_ptr,
+          out_b_ptr,
+          op,
+          shape,
+          a_strides,
+          b_strides,
+          out_strides,
+          0);
       return;
     case 2:
-      binary_op_dims2<T, U, Op>(a, b, out_a, out_b, op);
-      return;
-    case 3:
-      binary_op_dims3<T, U, Op>(a, b, out_a, out_b, op);
-      return;
-    case 4:
-      binary_op_dims4<T, U, Op>(a, b, out_a, out_b, op);
+      binary_op_dims<T, U, Op, 2>(
+          a_ptr,
+          b_ptr,
+          out_a_ptr,
+          out_b_ptr,
+          op,
+          shape,
+          a_strides,
+          b_strides,
+          out_strides,
+          0);
       return;
   }
 
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst_a = out_a.data<U>();
-  U* dst_b = out_b.data<U>();
-  for (size_t i = 0; i < out_a.size(); i++) {
-    int a_idx = elem_to_loc(i, a.shape(), a.strides());
-    int b_idx = elem_to_loc(i, b.shape(), b.strides());
-    std::tie(dst_a[i], dst_b[i]) = op(a_ptr[a_idx], b_ptr[b_idx]);
+  ContiguousIterator<size_t> a_it(shape, a_strides, ndim - 2);
+  ContiguousIterator<size_t> b_it(shape, b_strides, ndim - 2);
+  size_t stride = out_strides[ndim - 3];
+  for (size_t elem = 0; elem < a.size(); elem += stride) {
+    binary_op_dims<T, U, Op, 2>(
+        a_ptr + a_it.loc,
+        b_ptr + b_it.loc,
+        out_a_ptr + elem,
+        out_b_ptr + elem,
+        op,
+        shape,
+        a_strides,
+        b_strides,
+        out_strides,
+        ndim - 2);
+    a_it.step();
+    b_it.step();
   }
 }
 
-template <typename T, typename U, typename Op>
-void binary_op_dispatch_dims(
-    const array& a,
-    const array& b,
-    array& out_a,
-    array& out_b,
-    Op op,
-    int dim,
-    int stride) {
-  // Number of dimensions to loop over for vectorized ops
-  switch (dim) {
-    case 1:
-      binary_op_dims1<T, U, Op>(a, b, out_a, out_b, op, stride);
-      return;
-    case 2:
-      binary_op_dims2<T, U, Op>(a, b, out_a, out_b, op, stride);
-      return;
-  }
-
-  const T* a_ptr = a.data<T>();
-  const T* b_ptr = b.data<T>();
-  U* dst_a = out_a.data<U>();
-  U* dst_b = out_b.data<U>();
-  for (size_t i = 0; i < out_a.size(); i += stride) {
-    int a_idx = elem_to_loc(i, a.shape(), a.strides());
-    int b_idx = elem_to_loc(i, b.shape(), b.strides());
-    op(a_ptr + a_idx, b_ptr + b_idx, dst_a, dst_b, stride);
-    dst_a += stride;
-    dst_b += stride;
-  }
-}
-
-template <
-    typename T,
-    typename U,
-    typename Op,
-    typename OpSV,
-    typename OpVS,
-    typename OpVV>
+template <typename T, typename U = T, typename Op>
 void binary_op(
     const array& a,
     const array& b,
-    array& out_a,
-    array& out_b,
-    Op op,
-    OpSV opsv,
-    OpVS opvs,
-    OpVV opvv) {
+    std::vector<array>& outputs,
+    Op op) {
   auto bopt = get_binary_op_type(a, b);
+  auto& out_a = outputs[0];
+  auto& out_b = outputs[1];
   set_binary_op_output_data(a, b, out_a, bopt);
   set_binary_op_output_data(a, b, out_b, bopt);
 
   // The full computation is scalar scalar so call the base op once
+  if (bopt == BinaryOpType::General) {
+    binary_op_dispatch_dims<T, U, Op>(a, b, out_a, out_b, op);
+    return;
+  }
+
+  auto a_ptr = a.data<T>();
+  auto b_ptr = b.data<T>();
+  auto out_a_ptr = out_a.data<U>();
+  auto out_b_ptr = out_b.data<U>();
   if (bopt == BinaryOpType::ScalarScalar) {
-    std::tie(*(out_a.data<U>()), *(out_b.data<U>())) =
-        op(*a.data<T>(), *b.data<T>());
-    return;
-  }
-
-  // The full computation is scalar vector so delegate to the op
-  if (bopt == BinaryOpType::ScalarVector) {
-    opsv(
-        a.data<T>(),
-        b.data<T>(),
-        out_a.data<U>(),
-        out_b.data<U>(),
-        b.data_size());
-    return;
-  }
-
-  // The full computation is vector scalar so delegate to the op
-  if (bopt == BinaryOpType::VectorScalar) {
-    opvs(
-        a.data<T>(),
-        b.data<T>(),
-        out_a.data<U>(),
-        out_b.data<U>(),
-        a.data_size());
-    return;
-  }
-
-  // The full computation is vector vector so delegate to the op
-  if (bopt == BinaryOpType::VectorVector) {
-    opvv(
-        a.data<T>(),
-        b.data<T>(),
-        out_a.data<U>(),
-        out_b.data<U>(),
-        out_a.size());
-    return;
-  }
-
-  // General computation so let's try to optimize
-
-  // Get the left-most dim such that the array is row contiguous after
-  auto& strides = out_a.strides();
-  auto leftmost_rc_dim = [&strides](const array& arr) {
-    int d = arr.ndim() - 1;
-    for (; d >= 0 && arr.strides()[d] == strides[d]; d--) {
+    std::tie(*out_a_ptr, *out_b_ptr) = op(*a_ptr, *b_ptr);
+  } else if (bopt == BinaryOpType::ScalarVector) {
+    for (size_t i = 0; i < b.size(); ++i) {
+      std::tie(*out_a_ptr, *out_b_ptr) = op(*a_ptr, *b_ptr);
+      out_a_ptr++;
+      out_b_ptr++;
+      b_ptr++;
     }
-    return d + 1;
-  };
-  auto a_rc_dim = leftmost_rc_dim(a);
-  auto b_rc_dim = leftmost_rc_dim(b);
-
-  // Get the left-most dim such that the array is a broadcasted "scalar" after
-  auto leftmost_s_dim = [](const array& arr) {
-    int d = arr.ndim() - 1;
-    for (; d >= 0 && arr.strides()[d] == 0; d--) {
+  } else if (bopt == BinaryOpType::VectorScalar) {
+    for (size_t i = 0; i < a.size(); ++i) {
+      std::tie(*out_a_ptr, *out_b_ptr) = op(*a_ptr, *b_ptr);
+      out_a_ptr++;
+      out_b_ptr++;
+      a_ptr++;
+    }
+  } else { // VectorVector
+    for (size_t i = 0; i < a.size(); ++i) {
+      std::tie(*out_a_ptr, *out_b_ptr) = op(*a_ptr, *b_ptr);
+      out_a_ptr++;
+      out_b_ptr++;
+      a_ptr++;
+      b_ptr++;
     }
-    return d + 1;
-  };
-  auto a_s_dim = leftmost_s_dim(a);
-  auto b_s_dim = leftmost_s_dim(b);
-
-  auto ndim = out_a.ndim();
-
-  // Case 1: LxM and FxM where L and F are broadcastable and M is row contiguous
-  int dim = ndim;
-  if (int d = std::max(a_rc_dim, b_rc_dim); d < ndim) {
-    bopt = BinaryOpType::VectorVector;
-    dim = d;
-    // Case 2: LxM and Fx1 where L and F are broadcastable and M is row
-    // contiguous
-  } else if (int d = std::max(a_rc_dim, b_s_dim); d < ndim) {
-    bopt = BinaryOpType::VectorScalar;
-    dim = d;
-    // Case 3: Lx1 and FxM where L and F are broadcastable and M is row
-    // contiguous
-  } else if (int d = std::max(a_s_dim, b_rc_dim); d < ndim) {
-    bopt = BinaryOpType::ScalarVector;
-    dim = d;
-  }
-
-  // Can be sure dim > 0 since otherwise we would have used one of the fully
-  // contiguous methods above. Except for the case that the flags do not
-  // correspond to the underlying contiguity.
-  size_t stride;
-  if (dim == 0 || strides[dim - 1] < 16) {
-    stride = 1;
-    bopt = BinaryOpType::General;
-    dim = ndim;
-  } else {
-    stride = strides[dim - 1];
-  }
-
-  switch (bopt) {
-    case BinaryOpType::VectorVector:
-      binary_op_dispatch_dims<T, U>(a, b, out_a, out_b, opvv, dim, stride);
-      break;
-    case BinaryOpType::VectorScalar:
-      binary_op_dispatch_dims<T, U>(a, b, out_a, out_b, opvs, dim, stride);
-      break;
-    case BinaryOpType::ScalarVector:
-      binary_op_dispatch_dims<T, U>(a, b, out_a, out_b, opsv, dim, stride);
-      break;
-    default:
-      binary_op_dispatch_dims<T, U>(a, b, out_a, out_b, op);
-      break;
   }
 }
 
-template <typename T, typename Op, typename OpSV, typename OpVS, typename OpVV>
-void binary_op(
-    const array& a,
-    const array& b,
-    std::vector<array>& outputs,
-    Op op,
-    OpSV opsv,
-    OpVS opvs,
-    OpVV opvv) {
-  // TODO: The following mess of constexpr evaluations can probably be achieved
-  //       with template specializations and overloading. Would it be simpler?
-
-  if (std::is_same<decltype(opsv), UseDefaultBinaryOp>::value) {
-    if (std::is_same<decltype(opvs), UseDefaultBinaryOp>::value) {
-      if (std::is_same<decltype(opvv), UseDefaultBinaryOp>::value) {
-        // All ops are UseDefaultBinaryOp (why oh why would someone call that?)
-        binary_op<T, T>(
-            a,
-            b,
-            outputs[0],
-            outputs[1],
-            op,
-            DefaultScalarVector<T, T, Op>(op),
-            DefaultVectorScalar<T, T, Op>(op),
-            DefaultVectorVector<T, T, Op>(op));
-      } else {
-        // opsv and opvs were UseDefaultBinaryOp
-        binary_op<T, T>(
-            a,
-            b,
-            outputs[0],
-            outputs[1],
-            op,
-            DefaultScalarVector<T, T, Op>(op),
-            DefaultVectorScalar<T, T, Op>(op),
-            opvv);
-      }
-    } else if (std::is_same<decltype(opvv), UseDefaultBinaryOp>::value) {
-      // opsv and opvv were UseDefaultBinaryOp
-      binary_op<T, T>(
-          a,
-          b,
-          outputs[0],
-          outputs[1],
-          op,
-          DefaultScalarVector<T, T, Op>(op),
-          opvs,
-          DefaultVectorVector<T, T, Op>(op));
-    } else {
-      // opsv was UseDefaultBinaryOp
-      binary_op<T, T>(
-          a,
-          b,
-          outputs[0],
-          outputs[1],
-          op,
-          DefaultScalarVector<T, T, Op>(op),
-          opvs,
-          opvv);
-    }
-  } else if (std::is_same<decltype(opvs), UseDefaultBinaryOp>::value) {
-    if (std::is_same<decltype(opvv), UseDefaultBinaryOp>::value) {
-      // opvs and opvv were UseDefaultBinaryOp
-      binary_op<T, T>(
-          a,
-          b,
-          outputs[0],
-          outputs[1],
-          op,
-          opsv,
-          DefaultVectorScalar<T, T, Op>(op),
-          DefaultVectorVector<T, T, Op>(op));
-    } else {
-      // opvs was UseDefaultBinaryOp
-      binary_op<T, T>(
-          a,
-          b,
-          outputs[0],
-          outputs[1],
-          op,
-          opsv,
-          DefaultVectorScalar<T, T, Op>(op),
-          opvv);
-    }
-  } else if (std::is_same<decltype(opvv), UseDefaultBinaryOp>::value) {
-    // opvv was UseDefaultBinaryOp
-    binary_op<T, T>(
-        a,
-        b,
-        outputs[0],
-        outputs[1],
-        op,
-        opsv,
-        opvs,
-        DefaultVectorVector<T, T, Op>(op));
-  } else {
-    // All ops provided
-    binary_op<T, T>(a, b, outputs[0], outputs[1], op, opsv, opvs, opvv);
-  }
-}
-
-template <typename T, typename Op>
-void binary_op(
-    const array& a,
-    const array& b,
-    std::vector<array>& outputs,
-    Op op) {
-  DefaultScalarVector<T, T, Op> opsv(op);
-  DefaultVectorScalar<T, T, Op> opvs(op);
-  DefaultVectorVector<T, T, Op> opvv(op);
-  binary_op<T, T>(a, b, outputs[0], outputs[1], op, opsv, opvs, opvv);
-}
-
-template <typename... Ops>
+template <typename Op>
 void binary(
     const array& a,
     const array& b,
     std::vector<array>& outputs,
-    Ops... ops) {
+    Op op) {
   switch (outputs[0].dtype()) {
     case bool_:
-      binary_op<bool>(a, b, outputs, ops...);
+      binary_op<bool>(a, b, outputs, op);
       break;
     case uint8:
-      binary_op<uint8_t>(a, b, outputs, ops...);
+      binary_op<uint8_t>(a, b, outputs, op);
       break;
     case uint16:
-      binary_op<uint16_t>(a, b, outputs, ops...);
+      binary_op<uint16_t>(a, b, outputs, op);
       break;
     case uint32:
-      binary_op<uint32_t>(a, b, outputs, ops...);
+      binary_op<uint32_t>(a, b, outputs, op);
       break;
     case uint64:
-      binary_op<uint64_t>(a, b, outputs, ops...);
+      binary_op<uint64_t>(a, b, outputs, op);
       break;
     case int8:
-      binary_op<int8_t>(a, b, outputs, ops...);
+      binary_op<int8_t>(a, b, outputs, op);
       break;
     case int16:
-      binary_op<int16_t>(a, b, outputs, ops...);
+      binary_op<int16_t>(a, b, outputs, op);
       break;
     case int32:
-      binary_op<int32_t>(a, b, outputs, ops...);
+      binary_op<int32_t>(a, b, outputs, op);
       break;
     case int64:
-      binary_op<int64_t>(a, b, outputs, ops...);
+      binary_op<int64_t>(a, b, outputs, op);
       break;
     case float16:
-      binary_op<float16_t>(a, b, outputs, ops...);
+      binary_op<float16_t>(a, b, outputs, op);
       break;
     case float32:
-      binary_op<float>(a, b, outputs, ops...);
+      binary_op<float>(a, b, outputs, op);
       break;
     case bfloat16:
-      binary_op<bfloat16_t>(a, b, outputs, ops...);
+      binary_op<bfloat16_t>(a, b, outputs, op);
       break;
     case complex64:
-      binary_op<complex64_t>(a, b, outputs, ops...);
+      binary_op<complex64_t>(a, b, outputs, op);
       break;
   }
 }

mlx/backend/common/common.cpp

@@ -66,7 +66,7 @@ void Copy::eval(const std::vector<array>& inputs, array& out) {
   out.copy_shared_buffer(inputs[0]);
 }
 
-void CustomVJP::eval(
+void CustomTransforms::eval(
     const std::vector<array>& inputs,
     std::vector<array>& outputs) {
   assert(inputs.size() > outputs.size());
@@ -156,8 +156,7 @@ std::pair<bool, std::vector<size_t>> Reshape::prepare_reshape(
   }
 
   // Firstly let's collapse all the contiguous dimensions of the input
-  auto [shape, _strides] = collapse_contiguous_dims(in);
-  auto& strides = _strides[0];
+  auto [shape, strides] = collapse_contiguous_dims(in);
 
   // If shapes fit exactly in the contiguous dims then no copy is necessary so
   // let's check.

mlx/backend/common/compiled.cpp

@@ -18,7 +18,8 @@ void print_constant(std::ostream& os, const array& x) {
     case complex64:
       return print_complex_constant<complex64_t>(os, x);
     case int8:
-      return print_int_constant<int8_t>(os, x);
+      os << static_cast<int32_t>(x.item<int8_t>());
+      return;
     case int16:
       return print_int_constant<int16_t>(os, x);
     case int32:
@@ -26,7 +27,8 @@ void print_constant(std::ostream& os, const array& x) {
     case int64:
       return print_int_constant<int64_t>(os, x);
     case uint8:
-      return print_int_constant<uint8_t>(os, x);
+      os << static_cast<uint32_t>(x.item<uint8_t>());
+      return;
     case uint16:
       return print_int_constant<uint16_t>(os, x);
     case uint32:
@@ -205,8 +207,8 @@ void compiled_allocate_outputs(
       // - Donatable
       // - Correct size
       // - Not a constant
-      if (in.flags().row_contiguous && in.nbytes() == outputs[o].nbytes() &&
-          in.is_donatable() &&
+      if (in.flags().row_contiguous && in.size() == outputs[o].size() &&
+          in.itemsize() == outputs[o].itemsize() && in.is_donatable() &&
           constant_ids_.find(inputs_[i].id()) == constant_ids_.end()) {
         if (move_buffers) {
           outputs[o].move_shared_buffer(

mlx/backend/common/compiled_cpu.cpp

@@ -2,6 +2,7 @@
 
 #include <dlfcn.h>
 #include <filesystem>
+#include <fstream>
 #include <list>
 
 #include "mlx/backend/common/compiled.h"

mlx/backend/common/conv.cpp

@@ -684,6 +684,32 @@ void dispatch_slow_conv_3D(
 // Explicit gemm conv
 ///////////////////////////////////////////////////////////////////////////////
 
+template <typename T>
+void flip_spatial_dims_inplace(array& wt) {
+  T* x = wt.data<T>();
+  size_t out_channels = wt.shape(0);
+  size_t in_channels = wt.shape(-1);
+
+  // Calculate the total size of the spatial dimensions
+  int spatial_size = 1;
+  for (int d = 1; d < wt.ndim() - 1; ++d) {
+    spatial_size *= wt.shape(d);
+  }
+
+  for (size_t i = 0; i < out_channels; i++) {
+    T* top = x + i * spatial_size * in_channels;
+    T* bottom =
+        x + i * spatial_size * in_channels + (spatial_size - 1) * in_channels;
+    for (size_t j = 0; j < spatial_size / 2; j++) {
+      for (size_t k = 0; k < in_channels; k++) {
+        std::swap(top[k], bottom[k]);
+      }
+      top += in_channels;
+      bottom -= in_channels;
+    }
+  }
+}
+
 void explicit_gemm_conv_1D_cpu(
     const array& in,
     const array& wt,
@@ -910,7 +936,8 @@ void explicit_gemm_conv_ND_cpu(
     array out,
     const std::vector<int>& padding,
     const std::vector<int>& wt_strides,
-    const std::vector<int>& wt_dilation) {
+    const std::vector<int>& wt_dilation,
+    const bool flip) {
   const int N = in.shape(0); // Batch size, should be the same as out.shape(0)
   const auto iDim = std::vector<int>(
       in.shape().begin() + 1, in.shape().end() - 1); // Input spatial dim
@@ -1000,6 +1027,14 @@ void explicit_gemm_conv_ND_cpu(
     copy(wt, gemm_wt, ctype);
   }
 
+  if (flip) {
+    auto gemm_wt_ = array(gemm_wt.shape(), float32, nullptr, {});
+    copy(gemm_wt, gemm_wt_, CopyType::Vector);
+
+    flip_spatial_dims_inplace<float>(gemm_wt_);
+    gemm_wt = gemm_wt_;
+  }
+
   if (out.dtype() != float32) {
     gemm_out = array(out.shape(), float32, nullptr, {});
     gemm_out.set_data(allocator::malloc_or_wait(gemm_out.nbytes()));
@@ -1042,10 +1077,15 @@ void conv_1D_cpu(
     const std::vector<int>& wt_dilation,
     const std::vector<int>& in_dilation,
     bool flip) {
+  const int groups = in.shape().back() / wt.shape().back();
   if (wt_dilation[0] == 1 && in_dilation[0] == 1 && !flip) {
     return explicit_gemm_conv_1D_cpu(
         in, wt, out, padding, wt_strides, wt_dilation);
   }
+  if (wt_dilation[0] == 1 && in_dilation[0] == 1 && groups == 1) {
+    return explicit_gemm_conv_ND_cpu(
+        in, wt, out, padding, wt_strides, wt_dilation, flip);
+  }
 
   return dispatch_slow_conv_1D(
       in, wt, out, padding, wt_strides, wt_dilation, in_dilation, flip);
@@ -1060,6 +1100,13 @@ void conv_2D_cpu(
     const std::vector<int>& wt_dilation,
     const std::vector<int>& in_dilation,
     bool flip) {
+  const int groups = in.shape().back() / wt.shape().back();
+  if (wt_dilation[0] == 1 && wt_dilation[1] == 1 && in_dilation[0] == 1 &&
+      in_dilation[1] == 1 && groups == 1) {
+    return explicit_gemm_conv_ND_cpu(
+        in, wt, out, padding, wt_strides, wt_dilation, flip);
+  }
+
   return dispatch_slow_conv_2D(
       in, wt, out, padding, wt_strides, wt_dilation, in_dilation, flip);
 }
@@ -1073,6 +1120,14 @@ void conv_3D_cpu(
     const std::vector<int>& wt_dilation,
     const std::vector<int>& in_dilation,
     bool flip) {
+  const int groups = in.shape().back() / wt.shape().back();
+  if (wt_dilation[0] == 1 && wt_dilation[1] == 1 && wt_dilation[2] == 1 &&
+      in_dilation[0] == 1 && in_dilation[1] == 1 && in_dilation[2] == 1 &&
+      groups == 1) {
+    return explicit_gemm_conv_ND_cpu(
+        in, wt, out, padding, wt_strides, wt_dilation, flip);
+  }
+
   return dispatch_slow_conv_3D(
       in, wt, out, padding, wt_strides, wt_dilation, in_dilation, flip);
 }
@@ -1125,7 +1180,7 @@ void Convolution::eval(const std::vector<array>& inputs, array& out) {
   else {
     std::ostringstream msg;
     msg << "[Convolution::eval] Convolution currently only supports"
-        << " 1D and 2D convolutions. Got inputs with " << in.ndim() - 2
+        << " 1D, 2D and 3D convolutions. Got inputs with " << in.ndim() - 2
         << " spatial dimensions";
     throw std::invalid_argument(msg.str());
   }

mlx/backend/common/copy.cpp

@@ -4,6 +4,7 @@
 
 #include "mlx/allocator.h"
 #include "mlx/backend/common/copy.h"
+#include "mlx/backend/common/utils.h"
 
 namespace mlx::core {
 
@@ -25,252 +26,117 @@ void copy_vector(const array& src, array& dst) {
   std::copy(src_ptr, src_ptr + src.data_size(), dst_ptr);
 }
 
-template <typename SrcT, typename DstT, typename stride_t>
-void copy_general_dim1(
-    const array& src,
-    array& dst,
-    const std::vector<int>& data_shape,
-    const std::vector<stride_t>& i_strides,
-    int64_t i_offset) {
-  const SrcT* src_ptr = src.data<SrcT>();
-  DstT* dst_ptr = dst.data<DstT>();
-  stride_t src_idx = i_offset;
-  stride_t dst_idx = 0;
-  for (int i = 0; i < data_shape[0]; ++i) {
-    dst_ptr[dst_idx++] = static_cast<DstT>(src_ptr[src_idx]);
-    src_idx += i_strides[0];
-  }
-}
+template <typename SrcT, typename DstT, typename StrideT, int D>
+inline void copy_dims(
+    const SrcT* src,
+    DstT* dst,
+    const std::vector<int>& shape,
+    const std::vector<StrideT>& i_strides,
+    const std::vector<StrideT>& o_strides,
+    int axis) {
+  auto stride_src = i_strides[axis];
+  auto stride_dst = o_strides[axis];
+  auto N = shape[axis];
 
-template <typename SrcT, typename DstT>
-inline void copy_general_dim1(const array& src, array& dst) {
-  return copy_general_dim1<SrcT, DstT, size_t>(
-      src, dst, src.shape(), src.strides(), 0);
-}
-
-template <typename SrcT, typename DstT, typename stride_t>
-void copy_general_dim2(
-    const array& src,
-    array& dst,
-    const std::vector<int>& data_shape,
-    const std::vector<stride_t>& i_strides,
-    int64_t i_offset) {
-  const SrcT* src_ptr = src.data<SrcT>();
-  DstT* dst_ptr = dst.data<DstT>();
-  stride_t src_idx = i_offset;
-  stride_t dst_idx = 0;
-  for (int i = 0; i < data_shape[0]; ++i) {
-    for (int j = 0; j < data_shape[1]; ++j) {
-      dst_ptr[dst_idx++] = static_cast<DstT>(src_ptr[src_idx]);
-      src_idx += i_strides[1];
+  for (int i = 0; i < N; i++) {
+    if constexpr (D > 1) {
+      copy_dims<SrcT, DstT, StrideT, D - 1>(
+          src, dst, shape, i_strides, o_strides, axis + 1);
+    } else {
+      *dst = static_cast<DstT>(*src);
     }
-    src_idx += i_strides[0] - i_strides[1] * data_shape[1];
+    src += stride_src;
+    dst += stride_dst;
   }
 }
 
-template <typename SrcT, typename DstT>
-inline void copy_general_dim2(const array& src, array& dst) {
-  return copy_general_dim2<SrcT, DstT, size_t>(
-      src, dst, src.shape(), src.strides(), 0);
-}
-
-template <typename SrcT, typename DstT, typename stride_t>
-void copy_general_dim3(
-    const array& src,
-    array& dst,
-    const std::vector<int>& data_shape,
-    const std::vector<stride_t>& i_strides,
-    int64_t i_offset) {
-  const SrcT* src_ptr = src.data<SrcT>();
-  DstT* dst_ptr = dst.data<DstT>();
-  stride_t src_idx = i_offset;
-  stride_t dst_idx = 0;
-  for (int i = 0; i < data_shape[0]; ++i) {
-    for (int j = 0; j < data_shape[1]; ++j) {
-      for (int k = 0; k < data_shape[2]; ++k) {
-        dst_ptr[dst_idx++] = static_cast<DstT>(src_ptr[src_idx]);
-        src_idx += i_strides[2];
-      }
-      src_idx += i_strides[1] - i_strides[2] * data_shape[2];
-    }
-    src_idx += i_strides[0] - i_strides[1] * data_shape[1];
-  }
-}
-
-template <typename SrcT, typename DstT>
-inline void copy_general_dim3(const array& src, array& dst) {
-  return copy_general_dim3<SrcT, DstT, size_t>(
-      src, dst, src.shape(), src.strides(), 0);
-}
-
-template <typename SrcT, typename DstT, typename stride_t>
-void copy_general_dim4(
-    const array& src,
-    array& dst,
-    const std::vector<int>& data_shape,
-    const std::vector<stride_t>& i_strides,
-    int64_t i_offset) {
-  const SrcT* src_ptr = src.data<SrcT>();
-  DstT* dst_ptr = dst.data<DstT>();
-  stride_t src_idx = i_offset;
-  stride_t dst_idx = 0;
-  for (int i = 0; i < data_shape[0]; ++i) {
-    for (int j = 0; j < data_shape[1]; ++j) {
-      for (int k = 0; k < data_shape[2]; ++k) {
-        for (int ii = 0; ii < data_shape[3]; ++ii) {
-          dst_ptr[dst_idx++] = static_cast<DstT>(src_ptr[src_idx]);
-          src_idx += i_strides[3];
-        }
-        src_idx += i_strides[2] - i_strides[3] * data_shape[3];
-      }
-      src_idx += i_strides[1] - i_strides[2] * data_shape[2];
-    }
-    src_idx += i_strides[0] - i_strides[1] * data_shape[1];
-  }
-}
-
-template <typename SrcT, typename DstT>
-inline void copy_general_dim4(const array& src, array& dst) {
-  return copy_general_dim4<SrcT, DstT, size_t>(
-      src, dst, src.shape(), src.strides(), 0);
-}
-
-template <typename SrcT, typename DstT, typename stride_t>
-void copy_general(
-    const array& src,
-    array& dst,
-    const std::vector<int>& data_shape,
-    const std::vector<stride_t>& i_strides,
-    int64_t i_offset) {
-  switch (src.ndim()) {
-    case 1:
-      copy_general_dim1<SrcT, DstT, stride_t>(
-          src, dst, data_shape, i_strides, i_offset);
-      return;
-    case 2:
-      copy_general_dim2<SrcT, DstT, stride_t>(
-          src, dst, data_shape, i_strides, i_offset);
-      return;
-    case 3:
-      copy_general_dim3<SrcT, DstT, stride_t>(
-          src, dst, data_shape, i_strides, i_offset);
-      return;
-    case 4:
-      copy_general_dim4<SrcT, DstT, stride_t>(
-          src, dst, data_shape, i_strides, i_offset);
-      return;
-  }
-
-  auto src_ptr = src.data<SrcT>() + i_offset;
-  auto dst_ptr = dst.data<DstT>();
-  for (size_t i = 0; i < dst.size(); ++i) {
-    stride_t src_elem = elem_to_loc(i, data_shape, i_strides);
-    dst_ptr[i] = static_cast<DstT>(src_ptr[src_elem]);
-  }
-}
-
-template <typename SrcT, typename DstT>
-inline void copy_general(const array& src, array& dst) {
-  return copy_general<SrcT, DstT, size_t>(
-      src, dst, src.shape(), src.strides(), 0);
-}
-
-template <typename SrcT, typename DstT, typename stride_t>
-inline void copy_general(
-    const array& src,
-    array& dst,
-    const std::vector<int>& data_shape,
-    const std::vector<stride_t>& i_strides,
-    const std::vector<stride_t>& o_strides,
-    int64_t i_offset,
-    int64_t o_offset) {
-  return copy_general<SrcT, DstT, stride_t>(
-      src, dst, data_shape, i_strides, i_offset);
-}
-
-template <typename SrcT, typename DstT, typename stride_t, int D>
-inline void copy_general_general_dims(
-    const array& src,
-    array& dst,
-    const std::vector<int>& data_shape,
-    const std::vector<stride_t>& i_strides,
-    const std::vector<stride_t>& o_strides,
-    stride_t i_offset,
-    stride_t o_offset) {
-  if constexpr (D > 1) {
-    int axis = src.ndim() - D;
-    auto stride_src = i_strides[axis];
-    auto stride_dst = o_strides[axis];
-    auto N = data_shape[axis];
-    for (int i = 0; i < N; i++) {
-      copy_general_general_dims<SrcT, DstT, stride_t, D - 1>(
-          src, dst, data_shape, i_strides, o_strides, i_offset, o_offset);
-      i_offset += stride_src;
-      o_offset += stride_dst;
-    }
-  } else {
-    int axis = src.ndim() - 1;
-    auto stride_src = i_strides[axis];
-    auto stride_dst = o_strides[axis];
-    auto N = data_shape[axis];
-    const SrcT* src_ptr = src.data<SrcT>() + i_offset;
-    DstT* dst_ptr = dst.data<DstT>() + o_offset;
-    for (int i = 0; i < N; i++) {
-      *dst_ptr = static_cast<DstT>(*src_ptr);
-      src_ptr += stride_src;
-      dst_ptr += stride_dst;
-    }
-  }
-}
-
-template <typename SrcT, typename DstT, typename stride_t>
+template <typename SrcT, typename DstT, typename StrideT>
 void copy_general_general(
     const array& src,
     array& dst,
     const std::vector<int>& data_shape,
-    const std::vector<stride_t>& i_strides,
-    const std::vector<stride_t>& o_strides,
-    stride_t i_offset,
-    stride_t o_offset) {
-  switch (src.ndim()) {
-    case 1:
-      copy_general_general_dims<SrcT, DstT, stride_t, 1>(
-          src, dst, data_shape, i_strides, o_strides, i_offset, o_offset);
-      return;
-    case 2:
-      copy_general_general_dims<SrcT, DstT, stride_t, 2>(
-          src, dst, data_shape, i_strides, o_strides, i_offset, o_offset);
-      return;
-    case 3:
-      copy_general_general_dims<SrcT, DstT, stride_t, 3>(
-          src, dst, data_shape, i_strides, o_strides, i_offset, o_offset);
-      return;
-    case 4:
-      copy_general_general_dims<SrcT, DstT, stride_t, 4>(
-          src, dst, data_shape, i_strides, o_strides, i_offset, o_offset);
-      return;
-    case 5:
-      copy_general_general_dims<SrcT, DstT, stride_t, 5>(
-          src, dst, data_shape, i_strides, o_strides, i_offset, o_offset);
-      return;
+    const std::vector<StrideT>& i_strides,
+    const std::vector<StrideT>& o_strides,
+    int64_t i_offset,
+    int64_t o_offset) {
+  if (data_shape.empty()) {
+    auto val = static_cast<DstT>(*(src.data<SrcT>() + i_offset));
+    auto dst_ptr = dst.data<DstT>() + o_offset;
+    *dst_ptr = val;
+    return;
   }
-
-  int size = std::accumulate(
-      data_shape.end() - 5, data_shape.end(), 1, std::multiplies<int>());
-  for (int i = 0; i < src.size(); i += size) {
-    stride_t src_offset = i_offset + elem_to_loc(i, data_shape, i_strides);
-    stride_t dst_offset = o_offset + elem_to_loc(i, dst.shape(), o_strides);
-    copy_general_general_dims<SrcT, DstT, stride_t, 5>(
-        src, dst, data_shape, i_strides, o_strides, src_offset, dst_offset);
+  auto [shape, strides] = collapse_contiguous_dims(
+      data_shape, std::vector<std::vector<StrideT>>{i_strides, o_strides});
+  auto src_ptr = src.data<SrcT>() + i_offset;
+  auto dst_ptr = dst.data<DstT>() + o_offset;
+  int ndim = shape.size();
+  if (ndim == 1) {
+    copy_dims<SrcT, DstT, StrideT, 1>(
+        src_ptr, dst_ptr, shape, strides[0], strides[1], 0);
+    return;
+  } else if (ndim == 2) {
+    copy_dims<SrcT, DstT, StrideT, 2>(
+        src_ptr, dst_ptr, shape, strides[0], strides[1], 0);
+    return;
+  } else if (ndim == 3) {
+    copy_dims<SrcT, DstT, StrideT, 3>(
+        src_ptr, dst_ptr, shape, strides[0], strides[1], 0);
+    return;
+  }
+  ContiguousIterator<StrideT> in(shape, strides[0], ndim - 3);
+  ContiguousIterator<StrideT> out(shape, strides[1], ndim - 3);
+  StrideT stride = std::accumulate(
+      shape.end() - 3, shape.end(), 1, std::multiplies<StrideT>());
+  for (StrideT elem = 0; elem < src.size(); elem += stride) {
+    copy_dims<SrcT, DstT, StrideT, 3>(
+        src_ptr + in.loc,
+        dst_ptr + out.loc,
+        shape,
+        strides[0],
+        strides[1],
+        ndim - 3);
+    in.step();
+    out.step();
   }
 }
 
 template <typename SrcT, typename DstT>
 inline void copy_general_general(const array& src, array& dst) {
-  return copy_general_general<SrcT, DstT, size_t>(
+  copy_general_general<SrcT, DstT, size_t>(
       src, dst, src.shape(), src.strides(), dst.strides(), 0, 0);
 }
 
+template <typename SrcT, typename DstT, typename StrideT>
+void copy_general(
+    const array& src,
+    array& dst,
+    const std::vector<int>& data_shape,
+    const std::vector<StrideT>& i_strides,
+    const std::vector<StrideT>&,
+    int64_t i_offset,
+    int64_t o_offset) {
+  copy_general_general<SrcT, DstT, StrideT>(
+      src,
+      dst,
+      data_shape,
+      i_strides,
+      make_contiguous_strides<StrideT>(data_shape),
+      i_offset,
+      o_offset);
+}
+
+template <typename SrcT, typename DstT>
+inline void copy_general(const array& src, array& dst) {
+  copy_general_general<SrcT, DstT, size_t>(
+      src,
+      dst,
+      src.shape(),
+      src.strides(),
+      make_contiguous_strides<size_t>(src.shape()),
+      0,
+      0);
+}
+
 template <typename SrcT, typename DstT, typename... Args>
 void copy(const array& src, array& dst, CopyType ctype, Args&&... args) {
   switch (ctype) {
@@ -285,6 +151,7 @@ void copy(const array& src, array& dst, CopyType ctype, Args&&... args) {
       return;
     case CopyType::GeneralGeneral:
       copy_general_general<SrcT, DstT>(src, dst, std::forward<Args>(args)...);
+      return;
   }
 }
 
@@ -385,7 +252,7 @@ inline void copy_inplace_dispatch(
 } // namespace
 
 void copy_inplace(const array& src, array& dst, CopyType ctype) {
-  return copy_inplace_dispatch(src, dst, ctype);
+  copy_inplace_dispatch(src, dst, ctype);
 }
 
 void copy(const array& src, array& dst, CopyType ctype) {
@@ -415,20 +282,20 @@ void copy(const array& src, array& dst, CopyType ctype) {
   copy_inplace(src, dst, ctype);
 }
 
-template <typename stride_t>
+template <typename StrideT>
 void copy_inplace(
     const array& src,
     array& dst,
     const std::vector<int>& data_shape,
-    const std::vector<stride_t>& i_strides,
-    const std::vector<stride_t>& o_strides,
+    const std::vector<StrideT>& i_strides,
+    const std::vector<StrideT>& o_strides,
     int64_t i_offset,
     int64_t o_offset,
     CopyType ctype) {
   switch (ctype) {
     case CopyType::General:
     case CopyType::GeneralGeneral:
-      return copy_inplace_dispatch(
+      copy_inplace_dispatch(
           src,
           dst,
           ctype,
@@ -437,15 +304,24 @@ void copy_inplace(
           o_strides,
           i_offset,
           o_offset);
-
+      break;
     case CopyType::Scalar:
     case CopyType::Vector:
-      return copy_inplace_dispatch(src, dst, ctype);
+      copy_inplace_dispatch(src, dst, ctype);
   }
 }
 
-template <>
-void copy_inplace<int64_t>(
+template void copy_inplace<size_t>(
+    const array& src,
+    array& dst,
+    const std::vector<int>& data_shape,
+    const std::vector<size_t>& i_strides,
+    const std::vector<size_t>& o_strides,
+    int64_t i_offset,
+    int64_t o_offset,
+    CopyType ctype);
+
+template void copy_inplace<int64_t>(
     const array& src,
     array& dst,
     const std::vector<int>& data_shape,
@@ -453,24 +329,6 @@ void copy_inplace<int64_t>(
     const std::vector<int64_t>& o_strides,
     int64_t i_offset,
     int64_t o_offset,
-    CopyType ctype) {
-  switch (ctype) {
-    case CopyType::General:
-    case CopyType::GeneralGeneral:
-      return copy_inplace_dispatch(
-          src,
-          dst,
-          ctype,
-          data_shape,
-          i_strides,
-          o_strides,
-          i_offset,
-          o_offset);
-
-    case CopyType::Scalar:
-    case CopyType::Vector:
-      return copy_inplace_dispatch(src, dst, ctype);
-  }
-}
+    CopyType ctype);
 
 } // namespace mlx::core

mlx/backend/common/default_primitives.cpp

@@ -52,7 +52,7 @@ DEFAULT(Convolution)
 DEFAULT(Copy)
 DEFAULT(Cos)
 DEFAULT(Cosh)
-DEFAULT_MULTI(CustomVJP)
+DEFAULT_MULTI(CustomTransforms)
 DEFAULT_MULTI(Depends)
 DEFAULT(Divide)
 DEFAULT(NumberOfElements)
@@ -68,6 +68,7 @@ DEFAULT(Full)
 DEFAULT(Gather)
 DEFAULT(Greater)
 DEFAULT(GreaterEqual)
+DEFAULT(Hadamard)
 DEFAULT(Less)
 DEFAULT(LessEqual)
 DEFAULT(Load)

mlx/backend/common/hadamard.cpp

@@ -0,0 +1,107 @@
+// Copyright © 2024 Apple Inc.
+
+#include <cassert>
+
+#include "mlx/backend/common/copy.h"
+#include "mlx/backend/common/hadamard.h"
+#include "mlx/primitives.h"
+
+namespace mlx::core {
+
+// n = 2^k component
+template <typename T>
+void hadamard_n(array& out, int n, int m, float scale) {
+  for (int b = 0; b < out.size() / n; b++) {
+    size_t loc = b * n;
+    T* data_ptr = out.data<T>() + loc;
+    int h = 1;
+    int n_over_2 = n / 2;
+    while (h < n) {
+      for (int i = 0; i < n / 2; i++) {
+        int k = i & (h - 1);
+        int j = ((i - k) << 1) + k;
+        float x = *(data_ptr + j);
+        float y = *(data_ptr + j + h);
+        *(data_ptr + j) = x + y;
+        *(data_ptr + j + h) = x - y;
+        if (h == n_over_2) {
+          *(data_ptr + j) *= scale;
+          *(data_ptr + j + h) *= scale;
+        }
+      }
+      h <<= 1;
+    }
+  }
+}
+
+// m component
+template <typename T>
+void hadamard_m(array& out, int n, int m, float scale) {
+  auto h_matrices = hadamard_matrices();
+  auto& matrix = h_matrices[m];
+  auto start = 1;
+  auto end = matrix.find('\n', start);
+  std::vector<bool> hmat_vec;
+  while (end != std::string_view::npos) {
+    auto row = matrix.substr(start, end - start);
+    for (int i = 0; i < row.length(); i++) {
+      hmat_vec.push_back(row[i] == '+');
+    }
+    start = end + 1;
+    end = matrix.find('\n', start);
+  }
+
+  for (int b = 0; b < out.size() / m / n; b++) {
+    size_t loc = b * n * m;
+    T* data_ptr = out.data<T>() + loc;
+    for (int i = 0; i < n; i++) {
+      std::vector<float> out(m);
+      for (int j = 0; j < m; j++) {
+        for (int k = 0; k < m; k++) {
+          float x = *(data_ptr + i + k * n);
+          if (hmat_vec[k + j * m]) {
+            out[j] += x;
+          } else {
+            out[j] -= x;
+          }
+        }
+      }
+      for (int j = 0; j < m; j++) {
+        *(data_ptr + i + j * n) = out[j] * scale;
+      }
+    }
+  }
+}
+
+template <typename T>
+void hadamard(array& out, int n, int m, float scale) {
+  float n_scale = m > 1 ? 1.0 : scale;
+  hadamard_n<T>(out, n, m, n_scale);
+  if (m > 1) {
+    hadamard_m<T>(out, n, m, scale);
+  }
+}
+
+void Hadamard::eval(const std::vector<array>& inputs, array& out) {
+  assert(inputs.size() == 1);
+  auto& in = inputs[0];
+
+  // Copy input to output
+  copy(in, out, CopyType::General);
+
+  int axis = out.ndim() - 1;
+  auto [n, m] = decompose_hadamard(out.shape(axis));
+
+  switch (in.dtype()) {
+    case float32:
+      return hadamard<float>(out, n, m, scale_);
+    case float16:
+      return hadamard<float16_t>(out, n, m, scale_);
+    case bfloat16:
+      return hadamard<bfloat16_t>(out, n, m, scale_);
+    default:
+      throw std::invalid_argument("[hadamard] Unsupported type.");
+  }
+}
+
+} // namespace mlx::core

mlx/backend/common/hadamard.h

@@ -0,0 +1,105 @@
+// Copyright © 2024 Apple Inc.
+
+#pragma once
+
+#include <map>
+
+#include "mlx/utils.h"
+
+namespace mlx::core {
+
+// From http://neilsloane.com/hadamard/
+constexpr std::string_view h12 = R"(
++-++++++++++
+--+-+-+-+-+-
++++-++----++
++---+--+-++-
++++++-++----
++-+---+--+-+
+++--+++-++--
++--++---+--+
+++----+++-++
++--+-++---+-
+++++----+++-
++-+--+-++---
+)";
+
+constexpr std::string_view h20 = R"(
++----+----++--++-++-
+-+----+---+++---+-++
+--+----+---+++-+-+-+
+---+----+---+++++-+-
+----+----++--++-++-+
+-+++++-----+--+++--+
++-+++-+---+-+--+++--
+++-++--+---+-+--+++-
++++-+---+---+-+--+++
+++++-----++--+-+--++
+--++-+-++-+-----++++
+---++-+-++-+---+-+++
++---++-+-+--+--++-++
+++---++-+----+-+++-+
+-++---++-+----+++++-
+-+--+--++-+----+----
++-+-----++-+----+---
+-+-+-+---+--+----+--
+--+-+++------+----+-
++--+--++------+----+
+)";
+
+constexpr std::string_view h28 = R"(
++------++----++-+--+-+--++--
+-+-----+++-----+-+--+-+--++-
+--+-----+++---+-+-+----+--++
+---+-----+++---+-+-+-+--+--+
+----+-----+++---+-+-+++--+--
+-----+-----++++--+-+--++--+-
+------++----++-+--+-+--++--+
+--++++-+-------++--+++-+--+-
+---++++-+-----+-++--+-+-+--+
++---+++--+----++-++--+-+-+--
+++---++---+----++-++--+-+-+-
++++---+----+----++-++--+-+-+
+++++--------+-+--++-++--+-+-
+-++++--------+++--++--+--+-+
+-+-++-++--++--+--------++++-
++-+-++--+--++--+--------++++
+-+-+-++--+--++--+----+---+++
++-+-+-++--+--+---+---++---++
+++-+-+-++--+------+--+++---+
+-++-+-+-++--+------+-++++---
++-++-+---++--+------+-++++--
+-++--++-+-++-+++----++------
++-++--++-+-++-+++-----+-----
+++-++---+-+-++-+++-----+----
+-++-++-+-+-+-+--+++-----+---
+--++-++++-+-+----+++-----+--
++--++-+-++-+-+----+++-----+-
+++--++-+-++-+-+----++------+
+)";
+
+inline const std::map<int, std::string_view> hadamard_matrices() {
+  return {{12, h12}, {20, h20}, {28, h28}};
+}
+
+inline std::pair<int, int> decompose_hadamard(int n) {
+  // n = m*2^k
+  int m = 1;
+  if (!is_power_of_2(n)) {
+    auto h_matrices = hadamard_matrices();
+    for (auto [factor, _] : h_matrices) {
+      if (n % factor == 0) {
+        m = factor;
+        n /= factor;
+        break;
+      }
+    }
+    if (m == 1) {
+      throw std::invalid_argument(
+          "[hadamard] Only supports n = m*2^k where m in (1, 12, 20, 28).");
+    }
+  }
+  return {n, m};
+}
+
+} // namespace mlx::core

mlx/backend/common/indexing.cpp

@@ -1,5 +1,4 @@
 // Copyright © 2023 Apple Inc.
-
 #include <algorithm>
 #include <cassert>
 #include <cmath>
@@ -81,11 +80,18 @@ void gather(
   T* dst_ptr = out.data<T>();
   size_t out_idx = 0;
 
+  std::vector<ContiguousIterator<size_t>> its(inds.begin(), inds.end());
+  ContiguousIterator<size_t> src_it;
+  if (!can_copy && src.ndim() > 0) {
+    src_it = std::move(
+        ContiguousIterator<size_t>(slice_sizes, src.strides(), src.ndim()));
+  }
   for (int idx = 0; idx < ind_size; idx++) {
     size_t src_idx = 0;
     for (int ii = 0; ii < inds.size(); ++ii) {
       auto ax = axes[ii];
-      auto idx_loc = elem_to_loc(idx, inds[ii]);
+      auto idx_loc = its[ii].loc;
+      its[ii].step();
       auto idx_val =
           offset_neg_idx(inds[ii].data<IdxT>()[idx_loc], src.shape(ax));
       src_idx += (idx_val * src.strides()[ax]);
@@ -99,9 +105,10 @@ void gather(
       out_idx += slice_size;
     } else {
       for (int jj = 0; jj < slice_size; jj++) {
-        auto src_offset = elem_to_loc(jj, slice_sizes, src.strides());
-        dst_ptr[out_idx++] = src_ptr[src_idx + src_offset];
+        dst_ptr[out_idx++] = src_ptr[src_idx + src_it.loc];
+        src_it.step();
       }
+      src_it.reset();
     }
   }
 }
@@ -223,21 +230,29 @@ void scatter(
     update_size *= us;
   }
 
+  std::vector<ContiguousIterator<size_t>> its(inds.begin(), inds.end());
+  ContiguousIterator<size_t> update_it(updates);
+  ContiguousIterator<size_t> out_it(update_shape, out.strides(), out.ndim());
+
   for (int i = 0; i < n_updates; ++i) {
     size_t out_offset = 0;
     for (int j = 0; j < nind; ++j) {
       auto ax = axes[j];
-      auto idx_loc = elem_to_loc(i, inds[j]);
+      auto idx_loc = its[j].loc;
+      its[j].step();
       auto idx_val =
           offset_neg_idx(inds[j].data<IdxT>()[idx_loc], out.shape(ax));
       out_offset += (idx_val * out.strides()[ax]);
     }
+    update_it.seek(i * update_size);
     for (int j = 0; j < update_size; ++j) {
-      auto update_loc = elem_to_loc(i * update_size + j, updates);
-      auto out_loc = elem_to_loc(j, update_shape, out.strides());
-      op(updates.data<InT>()[update_loc],
-         out.data<InT>() + out_offset + out_loc);
+      op(updates.data<InT>()[update_it.loc],
+         out.data<InT>() + out_offset + out_it.loc);
+      update_it.step();
+      out_it.step();
     }
+    out_it.reset();
+    update_it.reset();
   }
 }
 

mlx/backend/common/inverse.cpp

@@ -10,9 +10,106 @@
 #include <lapack.h>
 #endif
 
+// Wrapper to account for differences in
+// LAPACK implementations (basically how to pass the 'uplo' string to fortran).
+int strtri_wrapper(char uplo, char diag, float* matrix, int N) {
+  int info;
+
+#ifdef LAPACK_FORTRAN_STRLEN_END
+  strtri_(
+      /* uplo = */ &uplo,
+      /* diag = */ &diag,
+      /* N = */ &N,
+      /* a = */ matrix,
+      /* lda = */ &N,
+      /* info = */ &info,
+      /* uplo_len = */ static_cast<size_t>(1),
+      /* diag_len = */ static_cast<size_t>(1));
+#else
+  strtri_(
+      /* uplo = */ &uplo,
+      /* diag = */ &diag,
+      /* N = */ &N,
+      /* a = */ matrix,
+      /* lda = */ &N,
+      /* info = */ &info);
+#endif
+
+  return info;
+}
+
 namespace mlx::core {
 
-void inverse_impl(const array& a, array& inv) {
+void general_inv(array& inv, int N, int i) {
+  int info;
+  auto ipiv = array::Data{allocator::malloc_or_wait(sizeof(int) * N)};
+  // Compute LU factorization.
+  sgetrf_(
+      /* m = */ &N,
+      /* n = */ &N,
+      /* a = */ inv.data<float>() + N * N * i,
+      /* lda = */ &N,
+      /* ipiv = */ static_cast<int*>(ipiv.buffer.raw_ptr()),
+      /* info = */ &info);
+
+  if (info != 0) {
+    std::stringstream ss;
+    ss << "inverse_impl: LU factorization failed with error code " << info;
+    throw std::runtime_error(ss.str());
+  }
+
+  static const int lwork_query = -1;
+  float workspace_size = 0;
+
+  // Compute workspace size.
+  sgetri_(
+      /* m = */ &N,
+      /* a = */ nullptr,
+      /* lda = */ &N,
+      /* ipiv = */ nullptr,
+      /* work = */ &workspace_size,
+      /* lwork = */ &lwork_query,
+      /* info = */ &info);
+
+  if (info != 0) {
+    std::stringstream ss;
+    ss << "inverse_impl: LU workspace calculation failed with error code "
+       << info;
+    throw std::runtime_error(ss.str());
+  }
+
+  const int lwork = workspace_size;
+  auto scratch = array::Data{allocator::malloc_or_wait(sizeof(float) * lwork)};
+
+  // Compute inverse.
+  sgetri_(
+      /* m = */ &N,
+      /* a = */ inv.data<float>() + N * N * i,
+      /* lda = */ &N,
+      /* ipiv = */ static_cast<int*>(ipiv.buffer.raw_ptr()),
+      /* work = */ static_cast<float*>(scratch.buffer.raw_ptr()),
+      /* lwork = */ &lwork,
+      /* info = */ &info);
+
+  if (info != 0) {
+    std::stringstream ss;
+    ss << "inverse_impl: inversion failed with error code " << info;
+    throw std::runtime_error(ss.str());
+  }
+}
+
+void tri_inv(array& inv, int N, int i, bool upper) {
+  const char uplo = upper ? 'L' : 'U';
+  const char diag = 'N';
+  int info = strtri_wrapper(uplo, diag, inv.data<float>() + N * N * i, N);
+  if (info != 0) {
+    std::stringstream ss;
+    ss << "inverse_impl: triangular inversion failed with error code " << info;
+    throw std::runtime_error(ss.str());
+  }
+}
+
+void inverse_impl(const array& a, array& inv, bool tri, bool upper) {
   // Lapack uses the column-major convention. We take advantage of the following
   // identity to avoid transposing (see
   // https://math.stackexchange.com/a/340234):
@@ -24,63 +121,11 @@ void inverse_impl(const array& a, array& inv) {
   const int N = a.shape(-1);
   const size_t num_matrices = a.size() / (N * N);
 
-  int info;
-  auto ipiv = array::Data{allocator::malloc_or_wait(sizeof(int) * N)};
-
   for (int i = 0; i < num_matrices; i++) {
-    // Compute LU factorization.
-    sgetrf_(
-        /* m = */ &N,
-        /* n = */ &N,
-        /* a = */ inv.data<float>() + N * N * i,
-        /* lda = */ &N,
-        /* ipiv = */ static_cast<int*>(ipiv.buffer.raw_ptr()),
-        /* info = */ &info);
-
-    if (info != 0) {
-      std::stringstream ss;
-      ss << "inverse_impl: LU factorization failed with error code " << info;
-      throw std::runtime_error(ss.str());
-    }
-
-    static const int lwork_query = -1;
-    float workspace_size = 0;
-
-    // Compute workspace size.
-    sgetri_(
-        /* m = */ &N,
-        /* a = */ nullptr,
-        /* lda = */ &N,
-        /* ipiv = */ nullptr,
-        /* work = */ &workspace_size,
-        /* lwork = */ &lwork_query,
-        /* info = */ &info);
-
-    if (info != 0) {
-      std::stringstream ss;
-      ss << "inverse_impl: LU workspace calculation failed with error code "
-         << info;
-      throw std::runtime_error(ss.str());
-    }
-
-    const int lwork = workspace_size;
-    auto scratch =
-        array::Data{allocator::malloc_or_wait(sizeof(float) * lwork)};
-
-    // Compute inverse.
-    sgetri_(
-        /* m = */ &N,
-        /* a = */ inv.data<float>() + N * N * i,
-        /* lda = */ &N,
-        /* ipiv = */ static_cast<int*>(ipiv.buffer.raw_ptr()),
-        /* work = */ static_cast<float*>(scratch.buffer.raw_ptr()),
-        /* lwork = */ &lwork,
-        /* info = */ &info);
-
-    if (info != 0) {
-      std::stringstream ss;
-      ss << "inverse_impl: inversion failed with error code " << info;
-      throw std::runtime_error(ss.str());
+    if (tri) {
+      tri_inv(inv, N, i, upper);
+    } else {
+      general_inv(inv, N, i);
     }
   }
 }
@@ -89,7 +134,7 @@ void Inverse::eval(const std::vector<array>& inputs, array& output) {
   if (inputs[0].dtype() != float32) {
     throw std::runtime_error("[Inverse::eval] only supports float32.");
   }
-  inverse_impl(inputs[0], output);
+  inverse_impl(inputs[0], output, tri_, upper_);
 }
 
 } // namespace mlx::core

mlx/backend/common/load.cpp

@@ -5,11 +5,9 @@
 #include <utility>
 
 #include "mlx/allocator.h"
-#include "mlx/io/load.h"
+#include "mlx/backend/common/load.h"
 #include "mlx/primitives.h"
 
-namespace mlx::core {
-
 namespace {
 
 template <const uint8_t scalar_size>
@@ -29,12 +27,14 @@ void swap_endianness(uint8_t* data_bytes, size_t N) {
 
 } // namespace
 
-void Load::eval(const std::vector<array>& inputs, array& out) {
-  assert(inputs.size() == 0);
-  out.set_data(allocator::malloc_or_wait(out.nbytes()));
+namespace mlx::core {
 
-  reader_->seek(offset_, std::ios_base::beg);
-  reader_->read(out.data<char>(), out.nbytes());
+void load(
+    array& out,
+    size_t offset,
+    const std::shared_ptr<io::Reader>& reader,
+    bool swap_endianness_) {
+  reader->read(out.data<char>(), out.nbytes(), offset);
 
   if (swap_endianness_) {
     switch (out.itemsize()) {
@@ -51,4 +51,11 @@ void Load::eval(const std::vector<array>& inputs, array& out) {
   }
 }
 
+void Load::eval(const std::vector<array>& inputs, array& out) {
+  assert(inputs.size() == 0);
+  out.set_data(allocator::malloc_or_wait(out.nbytes()));
+
+  load(out, offset_, reader_, swap_endianness_);
+}
+
 } // namespace mlx::core

mlx/backend/common/load.h

@@ -0,0 +1,14 @@
+// Copyright © 2024 Apple Inc.
+
+#include "mlx/array.h"
+#include "mlx/io/load.h"
+
+namespace mlx::core {
+
+void load(
+    array& out,
+    size_t offset,
+    const std::shared_ptr<io::Reader>& reader,
+    bool swap_endianess);
+
+} // namespace mlx::core

mlx/backend/common/make_compiled_preamble.sh

@@ -21,7 +21,7 @@ EOM
 
 fi
 
-CONTENT=$($GCC -I $SRCDIR -E $SRCDIR/mlx/backend/common/compiled_preamble.h 2>/dev/null)
+CONTENT=$($GCC -I "$SRCDIR" -E "$SRCDIR/mlx/backend/common/compiled_preamble.h" 2>/dev/null)
 
 cat << EOF > "$OUTPUT_FILE"
 const char* get_kernel_preamble() {

mlx/backend/common/ops.h

@@ -108,105 +108,105 @@ struct Abs {
   template <typename T>
   T operator()(T x) {
     return std::abs(x);
-  };
+  }
   uint8_t operator()(uint8_t x) {
     return x;
-  };
+  }
   uint16_t operator()(uint16_t x) {
     return x;
-  };
+  }
   uint32_t operator()(uint32_t x) {
     return x;
-  };
+  }
   uint64_t operator()(uint64_t x) {
     return x;
-  };
+  }
   bool operator()(bool x) {
     return x;
-  };
+  }
 };
 
 struct ArcCos {
   template <typename T>
   T operator()(T x) {
     return std::acos(x);
-  };
+  }
 };
 
 struct ArcCosh {
   template <typename T>
   T operator()(T x) {
     return std::acosh(x);
-  };
+  }
 };
 
 struct ArcSin {
   template <typename T>
   T operator()(T x) {
     return std::asin(x);
-  };
+  }
 };
 
 struct ArcSinh {
   template <typename T>
   T operator()(T x) {
     return std::asinh(x);
-  };
+  }
 };
 
 struct ArcTan {
   template <typename T>
   T operator()(T x) {
     return std::atan(x);
-  };
+  }
 };
 
 struct ArcTan2 {
   template <typename T>
   T operator()(T y, T x) {
     return std::atan2(y, x);
-  };
+  }
 };
 
 struct ArcTanh {
   template <typename T>
   T operator()(T x) {
     return std::atanh(x);
-  };
+  }
 };
 
 struct Ceil {
   template <typename T>
   T operator()(T x) {
     return std::ceil(x);
-  };
+  }
   int8_t operator()(int8_t x) {
     return x;
-  };
+  }
   int16_t operator()(int16_t x) {
     return x;
-  };
+  }
   int32_t operator()(int32_t x) {
     return x;
-  };
+  }
   int64_t operator()(int64_t x) {
     return x;
-  };
+  }
   uint8_t operator()(uint8_t x) {
     return x;
-  };
+  }
   uint16_t operator()(uint16_t x) {
     return x;
-  };
+  }
   uint32_t operator()(uint32_t x) {
     return x;
-  };
+  }
   uint64_t operator()(uint64_t x) {
     return x;
-  };
+  }
   bool operator()(bool x) {
     return x;
-  };
+  }
 };
 
 struct Conjugate {
@@ -219,35 +219,35 @@ struct Cos {
   template <typename T>
   T operator()(T x) {
     return std::cos(x);
-  };
+  }
 };
 
 struct Cosh {
   template <typename T>
   T operator()(T x) {
     return std::cosh(x);
-  };
+  }
 };
 
 struct Erf {
   template <typename T>
   T operator()(T x) {
     return static_cast<T>(fast_erf(static_cast<float>(x)));
-  };
+  }
 };
 
 struct ErfInv {
   template <typename T>
   T operator()(T x) {
     return static_cast<T>(fast_erfinv(static_cast<float>(x)));
-  };
+  }
 };
 
 struct Exp {
   template <typename T>
   T operator()(T x) {
     return fast_exp(x);
-  };
+  }
 
   complex64_t operator()(complex64_t x) {
     return std::exp(x);
@@ -258,83 +258,83 @@ struct Expm1 {
   template <typename T>
   T operator()(T x) {
     return expm1(x);
-  };
+  }
 };
 
 struct Floor {
   template <typename T>
   T operator()(T x) {
     return std::floor(x);
-  };
+  }
   int8_t operator()(int8_t x) {
     return x;
-  };
+  }
   int16_t operator()(int16_t x) {
     return x;
-  };
+  }
   int32_t operator()(int32_t x) {
     return x;
-  };
+  }
   int64_t operator()(int64_t x) {
     return x;
-  };
+  }
   uint8_t operator()(uint8_t x) {
     return x;
-  };
+  }
   uint16_t operator()(uint16_t x) {
     return x;
-  };
+  }
   uint32_t operator()(uint32_t x) {
     return x;
-  };
+  }
   uint64_t operator()(uint64_t x) {
     return x;
-  };
+  }
   bool operator()(bool x) {
     return x;
-  };
+  }
 };
 
 struct Log {
   template <typename T>
   T operator()(T x) {
     return std::log(x);
-  };
+  }
 };
 
 struct Log2 {
   template <typename T>
   T operator()(T x) {
     return std::log2(x);
-  };
+  }
 };
 
 struct Log10 {
   template <typename T>
   T operator()(T x) {
     return std::log10(x);
-  };
+  }
 };
 
 struct Log1p {
   template <typename T>
   T operator()(T x) {
     return log1p(x);
-  };
+  }
 };
 
 struct LogicalNot {
   template <typename T>
   T operator()(T x) {
     return !x;
-  };
+  }
 };
 
 struct Negative {
   template <typename T>
   T operator()(T x) {
     return -x;
-  };
+  }
 };
 
 struct Round {
@@ -373,55 +373,59 @@ struct Sign {
   uint64_t operator()(uint64_t x) {
     return x != 0;
   }
+
+  complex64_t operator()(complex64_t x) {
+    return x == complex64_t(0) ? x : x / std::abs(x);
+  }
 };
 
 struct Sin {
   template <typename T>
   T operator()(T x) {
     return std::sin(x);
-  };
+  }
 };
 
 struct Sinh {
   template <typename T>
   T operator()(T x) {
     return std::sinh(x);
-  };
+  }
 };
 
 struct Square {
   template <typename T>
   T operator()(T x) {
     return x * x;
-  };
+  }
 };
 
 struct Sqrt {
   template <typename T>
   T operator()(T x) {
     return std::sqrt(x);
-  };
+  }
 };
 
 struct Rsqrt {
   template <typename T>
   T operator()(T x) {
     return static_cast<decltype(x)>(1.0) / std::sqrt(x);
-  };
+  }
 };
 
 struct Tan {
   template <typename T>
   T operator()(T x) {
     return std::tan(x);
-  };
+  }
 };
 
 struct Tanh {
   template <typename T>
   T operator()(T x) {
     return std::tanh(x);
-  };
+  }
 };
 
 struct Add {
@@ -554,7 +558,7 @@ struct LogAddExp {
         ? maxval
         : static_cast<decltype(x)>(
               maxval + std::log1p(fast_exp(minval - maxval)));
-  };
+  }
 };
 
 struct Multiply {
@@ -602,14 +606,14 @@ struct LogicalAnd {
   template <typename T>
   T operator()(T x, T y) {
     return x && y;
-  };
+  }
 };
 
 struct LogicalOr {
   template <typename T>
   T operator()(T x, T y) {
     return x || y;
-  };
+  }
 };
 
 struct Select {
@@ -623,35 +627,35 @@ struct BitwiseAnd {
   template <typename T>
   T operator()(T x, T y) {
     return x & y;
-  };
+  }
 };
 
 struct BitwiseOr {
   template <typename T>
   T operator()(T x, T y) {
     return x | y;
-  };
+  }
 };
 
 struct BitwiseXor {
   template <typename T>
   T operator()(T x, T y) {
     return x ^ y;
-  };
+  }
 };
 
 struct LeftShift {
   template <typename T>
   T operator()(T x, T y) {
     return x << y;
-  };
+  }
 };
 
 struct RightShift {
   template <typename T>
   T operator()(T x, T y) {
     return x >> y;
-  };
+  }
 };
 
 } // namespace mlx::core::detail

mlx/backend/common/primitives.cpp

@@ -8,7 +8,6 @@
 
 #include "mlx/allocator.h"
 #include "mlx/backend/common/arange.h"
-#include "mlx/backend/common/binary.h"
 #include "mlx/backend/common/copy.h"
 #include "mlx/backend/common/ops.h"
 #include "mlx/backend/common/slicing.h"
@@ -314,20 +313,6 @@ void LogicalNot::eval(const std::vector<array>& inputs, array& out) {
   unary(in, out, detail::LogicalNot());
 }
 
-void LogicalAnd::eval(const std::vector<array>& inputs, array& out) {
-  assert(inputs.size() == 2); // LogicalAnd requires two input arrays
-  auto& in1 = inputs[0];
-  auto& in2 = inputs[1];
-  binary(in1, in2, out, detail::LogicalAnd());
-}
-
-void LogicalOr::eval(const std::vector<array>& inputs, array& out) {
-  assert(inputs.size() == 2); // LogicalOr requires two input arrays
-  auto& in1 = inputs[0];
-  auto& in2 = inputs[1];
-  binary(in1, in2, out, detail::LogicalOr());
-}
-
 void Negative::eval(const std::vector<array>& inputs, array& out) {
   assert(inputs.size() == 1);
   auto& in = inputs[0];
@@ -420,7 +405,8 @@ void Reshape::eval(const std::vector<array>& inputs, array& out) {
   auto [copy_necessary, out_strides] = prepare_reshape(in, out);
 
   if (copy_necessary) {
-    copy(in, out, in.data_size() == 1 ? CopyType::Scalar : CopyType::General);
+    out.set_data(allocator::malloc_or_wait(out.nbytes()));
+    copy_inplace(in, out, CopyType::General);
   } else {
     shared_buffer_reshape(in, out_strides, out);
   }
@@ -510,8 +496,16 @@ void Slice::eval(const std::vector<array>& inputs, array& out) {
         /* int64_t o_offset = */ 0,
         /* CopyType ctype = */ CopyType::General);
   } else {
+    size_t data_end = 1;
+    for (int i = 0; i < end_indices_.size(); ++i) {
+      if (in.shape()[i] > 1) {
+        auto end_idx = start_indices_[i] + out.shape()[i] * strides_[i] - 1;
+        data_end += end_idx * in.strides()[i];
+      }
+    }
+    size_t data_size = data_end - data_offset;
     std::vector<size_t> ostrides{inp_strides.begin(), inp_strides.end()};
-    shared_buffer_slice(in, ostrides, data_offset, out);
+    shared_buffer_slice(in, ostrides, data_offset, data_size, out);
   }
 }
 
@@ -609,11 +603,18 @@ void View::eval_cpu(const std::vector<array>& inputs, array& out) {
       strides[i] /= obytes;
     }
     out.copy_shared_buffer(
-        in, strides, in.flags(), in.data_size() * obytes / ibytes);
+        in, strides, in.flags(), in.data_size() * ibytes / obytes);
   } else {
-    auto tmp = array(in.shape(), in.dtype(), nullptr, {});
+    auto tmp = array(
+        in.shape(), in.dtype() == bool_ ? uint8 : in.dtype(), nullptr, {});
     tmp.set_data(allocator::malloc_or_wait(tmp.nbytes()));
-    copy_inplace(in, tmp, CopyType::General);
+    if (in.dtype() == bool_) {
+      auto in_tmp = array(in.shape(), uint8, nullptr, {});
+      in_tmp.copy_shared_buffer(in);
+      copy_inplace(in_tmp, tmp, CopyType::General);
+    } else {
+      copy_inplace(in, tmp, CopyType::General);
+    }
 
     auto flags = out.flags();
     flags.contiguous = true;

mlx/backend/common/reduce.cpp

@@ -87,6 +87,38 @@ struct OrReduce {
   }
 };
 
+struct MaxReduce {
+  template <typename T>
+  std::enable_if_t<std::is_integral_v<T>> operator()(T* y, T x) {
+    (*y) = (*y > x) ? *y : x;
+  };
+
+  template <typename T>
+  std::enable_if_t<!std::is_integral_v<T>> operator()(T* y, T x) {
+    if (std::isnan(x)) {
+      *y = x;
+    } else {
+      (*y) = (*y > x) ? *y : x;
+    }
+  };
+};
+
+struct MinReduce {
+  template <typename T>
+  std::enable_if_t<std::is_integral_v<T>> operator()(T* y, T x) {
+    (*y) = (*y < x) ? *y : x;
+  };
+
+  template <typename T>
+  std::enable_if_t<!std::is_integral_v<T>> operator()(T* y, T x) {
+    if (std::isnan(x)) {
+      *y = x;
+    } else {
+      (*y) = (*y < x) ? *y : x;
+    }
+  };
+};
+
 template <typename InT>
 void reduce_dispatch_out(
     const array& in,
@@ -104,63 +136,27 @@ void reduce_dispatch_out(
     }
     case Reduce::Sum: {
       auto op = [](auto y, auto x) { (*y) = (*y) + x; };
-      switch (out.dtype()) {
-        case bool_:
-          reduction_op<InT, bool>(in, out, axes, false, op);
-          break;
-        case uint8:
-          reduction_op<InT, uint8_t>(in, out, axes, 0, op);
-          break;
-        case uint16:
-          reduction_op<InT, uint16_t>(in, out, axes, 0, op);
-          break;
-        case uint32:
-          reduction_op<InT, uint32_t>(in, out, axes, 0, op);
-          break;
-        case uint64:
-          reduction_op<InT, uint64_t>(in, out, axes, 0, op);
-          break;
-        case int8:
-          reduction_op<InT, int8_t>(in, out, axes, 0, op);
-          break;
-        case int16:
-          reduction_op<InT, int16_t>(in, out, axes, 0, op);
-          break;
-        case int32:
-          reduction_op<InT, int32_t>(in, out, axes, 0, op);
-          break;
-        case int64:
-          reduction_op<InT, int64_t>(in, out, axes, 0, op);
-          break;
-        case float16:
-          reduction_op<InT, float16_t>(in, out, axes, 0.0f, op);
-          break;
-        case float32:
-          reduction_op<InT, float>(in, out, axes, 0.0f, op);
-          break;
-        case bfloat16:
-          reduction_op<InT, bfloat16_t>(in, out, axes, 0.0f, op);
-          break;
-        case complex64:
-          reduction_op<InT, complex64_t>(in, out, axes, complex64_t{0.0f}, op);
-          break;
+      if (out.dtype() == int32) {
+        // special case since the input type can be bool
+        reduction_op<InT, int32_t>(in, out, axes, 0, op);
+      } else {
+        reduction_op<InT, InT>(in, out, axes, 0, op);
       }
-    } break;
+      break;
+    }
     case Reduce::Prod: {
       auto op = [](auto y, auto x) { (*y) *= x; };
       reduction_op<InT, InT>(in, out, axes, 1, op);
       break;
     }
     case Reduce::Max: {
-      auto op = [](auto y, auto x) { (*y) = (*y > x) ? *y : x; };
       auto init = Limits<InT>::min;
-      reduction_op<InT, InT>(in, out, axes, init, op);
+      reduction_op<InT, InT>(in, out, axes, init, MaxReduce());
       break;
     }
     case Reduce::Min: {
-      auto op = [](auto y, auto x) { (*y) = (*y < x) ? *y : x; };
       auto init = Limits<InT>::max;
-      reduction_op<InT, InT>(in, out, axes, init, op);
+      reduction_op<InT, InT>(in, out, axes, init, MinReduce());
       break;
     }
   }
@@ -168,6 +164,29 @@ void reduce_dispatch_out(
 
 } // namespace
 
+void nd_loop(
+    std::function<void(int)> callback,
+    const std::vector<int>& shape,
+    const std::vector<size_t>& strides) {
+  std::function<void(int, int)> loop_inner;
+  loop_inner = [&](int dim, int offset) {
+    if (dim < shape.size() - 1) {
+      int size = shape[dim];
+      size_t stride = strides[dim];
+      for (int i = 0; i < size; i++) {
+        loop_inner(dim + 1, offset + i * stride);
+      }
+    } else {
+      int size = shape[dim];
+      size_t stride = strides[dim];
+      for (int i = 0; i < size; i++) {
+        callback(offset + i * stride);
+      }
+    }
+  };
+  loop_inner(0, 0);
+}
+
 void Reduce::eval(const std::vector<array>& inputs, array& out) {
   assert(inputs.size() == 1);
   auto& in = inputs[0];

mlx/backend/common/reduce.h

@@ -49,47 +49,18 @@ struct ReductionPlan {
   ReductionPlan(ReductionOpType type_) : type(type_) {}
 };
 
-namespace {
+ReductionPlan get_reduction_plan(const array& x, const std::vector<int>& axes);
 
 // Helper for the ndimensional strided loop
 // Should this be in utils?
-inline void nd_loop(
+void nd_loop(
     std::function<void(int)> callback,
     const std::vector<int>& shape,
-    const std::vector<size_t>& strides) {
-  std::function<void(int, int)> loop_inner;
-  loop_inner = [&](int dim, int offset) {
-    if (dim < shape.size() - 1) {
-      int size = shape[dim];
-      size_t stride = strides[dim];
-      for (int i = 0; i < size; i++) {
-        loop_inner(dim + 1, offset + i * stride);
-      }
-    } else {
-      int size = shape[dim];
-      size_t stride = strides[dim];
-      for (int i = 0; i < size; i++) {
-        callback(offset + i * stride);
-      }
-    }
-  };
-  loop_inner(0, 0);
-}
+    const std::vector<size_t>& strides);
 
 std::pair<std::vector<int>, std::vector<size_t>> shapes_without_reduction_axes(
     const array& x,
-    const std::vector<int>& axes) {
-  std::vector<int> shape = x.shape();
-  std::vector<size_t> strides = x.strides();
-
-  for (int i = axes.size() - 1; i >= 0; i--) {
-    int a = axes[i];
-    shape.erase(shape.begin() + a);
-    strides.erase(strides.begin() + a);
-  }
-
-  return std::make_pair(shape, strides);
-}
+    const std::vector<int>& axes);
 
 template <typename T, typename U, typename Op>
 struct DefaultStridedReduce {
@@ -123,102 +94,6 @@ struct DefaultContiguousReduce {
   }
 };
 
-ReductionPlan get_reduction_plan(const array& x, const std::vector<int> axes) {
-  // The data is all there and we are reducing over everything
-  if (x.size() == x.data_size() && axes.size() == x.ndim() &&
-      x.flags().contiguous) {
-    return ContiguousAllReduce;
-  }
-
-  // Row contiguous input so the output is row contiguous
-  if (x.flags().row_contiguous) {
-    // Merge consecutive axes
-    std::vector<int> shape = {x.shape(axes[0])};
-    std::vector<size_t> strides = {x.strides()[axes[0]]};
-    for (int i = 1; i < axes.size(); i++) {
-      if (axes[i] - 1 == axes[i - 1]) {
-        shape.back() *= x.shape(axes[i]);
-        strides.back() = x.strides()[axes[i]];
-      } else {
-        shape.push_back(x.shape(axes[i]));
-        strides.push_back(x.strides()[axes[i]]);
-      }
-    }
-
-    if (strides.back() == 1) {
-      return ReductionPlan(ContiguousReduce, shape, strides);
-    } else if (strides.back() > 1) {
-      return ReductionPlan(ContiguousStridedReduce, shape, strides);
-    }
-  }
-
-  // Let's check if we can optimize our access patterns
-  //
-  // 1. We have a reduction axis with stride 1. Simply call
-  //    GeneralContiguousReduce and be done with it.
-  // 2. We have transpositions and we are not reducing over the axis with
-  //    stride 1. However, we are reducing over an axis where everything is
-  //    contiguous in memory to the right of that axis. We can call strided
-  //    reduce and be done with it.
-  // 2. We have weird transpositions and expands. Copy the strides to the
-  //    output, then call strided reduce.
-
-  // Sort reduction axes by stride in order to merge them and figure out if we
-  // have a contiguous reduction.
-  std::vector<std::pair<int, size_t>> reductions;
-  for (auto a : axes) {
-    reductions.push_back(std::make_pair(x.shape(a), x.strides()[a]));
-  }
-  std::sort(reductions.begin(), reductions.end(), [](auto a, auto b) {
-    return a.second > b.second;
-  });
-  // Extract the two smallest and try to merge them in case the contiguous
-  // reduction can be bigger than just the last axis.
-  for (int i = reductions.size() - 1; i >= 1; i--) {
-    auto a = reductions[i];
-    auto b = reductions[i - 1];
-
-    // b.stride = a.shape * a.stride then a and b are contiguous
-    if (b.second == a.first * a.second) {
-      reductions.erase(reductions.begin() + i);
-      reductions[i - 1] = std::make_pair(a.first * b.first, a.second);
-    }
-  }
-
-  std::vector<int> shape;
-  std::vector<size_t> strides;
-  for (auto r : reductions) {
-    shape.push_back(r.first);
-    strides.push_back(r.second);
-  }
-
-  // We can call the contiguous reduction op for every weird way the input is
-  // structured in the rest of the axes.
-  if (strides.back() == 1) {
-    return ReductionPlan(GeneralContiguousReduce, shape, strides);
-  }
-
-  // Delegate to the general strided reduction op if the axes after
-  // strides.back() are contiguous.
-  if (strides.back() > 1) {
-    int size = 1;
-    for (int i = x.ndim() - 1; i >= 0; i--) {
-      if (axes.back() == i) {
-        continue;
-      }
-      if (x.strides()[i] != size) {
-        break;
-      }
-      size *= x.shape(i);
-    }
-    if (size >= strides.back()) {
-      return ReductionPlan(GeneralStridedReduce, shape, strides);
-    }
-  }
-
-  return ReductionPlan(GeneralReduce, shape, strides);
-}
-
 template <typename T, typename U, typename OpS, typename OpC, typename Op>
 void reduction_op(
     const array& x,
@@ -361,6 +236,4 @@ void reduction_op(
   reduction_op<T, U>(x, out, axes, init, ops, opc, op);
 }
 
-} // namespace
-
 } // namespace mlx::core

mlx/backend/common/reduce_utils.cpp

@@ -0,0 +1,147 @@
+// Copyright © 2024 Apple Inc.
+
+#include "mlx/backend/common/reduce.h"
+
+namespace mlx::core {
+
+std::pair<std::vector<int>, std::vector<size_t>> shapes_without_reduction_axes(
+    const array& x,
+    const std::vector<int>& axes) {
+  std::vector<int> shape = x.shape();
+  std::vector<size_t> strides = x.strides();
+
+  for (int i = axes.size() - 1; i >= 0; i--) {
+    int a = axes[i];
+    shape.erase(shape.begin() + a);
+    strides.erase(strides.begin() + a);
+  }
+
+  return std::make_pair(shape, strides);
+}
+
+ReductionPlan get_reduction_plan(const array& x, const std::vector<int>& axes) {
+  // The data is all there and we are reducing over everything
+  if (x.size() == x.data_size() && axes.size() == x.ndim() &&
+      x.flags().contiguous) {
+    return ContiguousAllReduce;
+  }
+
+  // Row contiguous input so the output is row contiguous
+  if (x.flags().row_contiguous) {
+    // Merge consecutive axes
+    std::vector<int> shape = {x.shape(axes[0])};
+    std::vector<size_t> strides = {x.strides()[axes[0]]};
+    for (int i = 1; i < axes.size(); i++) {
+      if (axes[i] - 1 == axes[i - 1] && x.shape(axes[i]) > 1) {
+        shape.back() *= x.shape(axes[i]);
+        strides.back() = x.strides()[axes[i]];
+      } else {
+        shape.push_back(x.shape(axes[i]));
+        strides.push_back(x.strides()[axes[i]]);
+      }
+    }
+
+    // Remove singleton axes from the plan
+    for (int i = shape.size() - 1; i >= 0; i--) {
+      if (shape[i] == 1) {
+        shape.erase(shape.begin() + i);
+        strides.erase(strides.begin() + i);
+      }
+    }
+
+    if (strides.back() == 1) {
+      return ReductionPlan(ContiguousReduce, shape, strides);
+    } else if (strides.back() > 1) {
+      return ReductionPlan(ContiguousStridedReduce, shape, strides);
+    }
+  }
+
+  // Let's check if we can optimize our access patterns
+  //
+  // 1. We have a reduction axis with stride 1. Simply call
+  //    GeneralContiguousReduce and be done with it.
+  // 2. We have transpositions and we are not reducing over the axis with
+  //    stride 1. However, we are reducing over an axis where everything is
+  //    contiguous in memory to the right of that axis. We can call strided
+  //    reduce and be done with it.
+  // 2. We have weird transpositions and expands. Copy the strides to the
+  //    output, then call strided reduce.
+
+  // Sort reduction axes by stride in order to merge them and figure out if we
+  // have a contiguous reduction.
+  std::vector<std::pair<int, size_t>> reductions;
+  for (auto a : axes) {
+    if (x.shape(a) > 1) {
+      reductions.push_back(std::make_pair(x.shape(a), x.strides()[a]));
+    }
+  }
+  std::sort(reductions.begin(), reductions.end(), [](auto a, auto b) {
+    bool a_is_zero = a.second == 0;
+    bool b_is_zero = b.second == 0;
+    return (a_is_zero != b_is_zero) ? a.second < b.second : a.second > b.second;
+  });
+  // Extract the two smallest and try to merge them in case the contiguous
+  // reduction can be bigger than just the last axis.
+  for (int i = reductions.size() - 1; i >= 1; i--) {
+    auto a = reductions[i];
+    auto b = reductions[i - 1];
+
+    // b.stride = a.shape * a.stride then a and b are contiguous
+    if (b.second == a.first * a.second) {
+      reductions.erase(reductions.begin() + i);
+      reductions[i - 1] = std::make_pair(a.first * b.first, a.second);
+    }
+  }
+
+  std::vector<int> shape;
+  std::vector<size_t> strides;
+  for (auto r : reductions) {
+    shape.push_back(r.first);
+    strides.push_back(r.second);
+  }
+
+  // We can call the contiguous reduction op for every weird way the input is
+  // structured in the rest of the axes.
+  if (strides.back() == 1) {
+    return ReductionPlan(GeneralContiguousReduce, shape, strides);
+  }
+
+  // Delegate to the general strided reduction op if the axes after
+  // strides.back() are contiguous.
+  if (strides.back() > 1) {
+    int size = 1;
+    bool have_expand = false;
+    for (int i = x.ndim() - 1; i >= 0; i--) {
+      if (axes.back() == i) {
+        continue;
+      }
+
+      size_t stride_i = x.strides()[i];
+      int shape_i = x.shape(i);
+      if (stride_i == 0) {
+        if (shape_i == 1) {
+          continue;
+        }
+
+        have_expand = true;
+        break;
+      }
+
+      if (stride_i != size && shape_i != 1) {
+        break;
+      }
+      size *= shape_i;
+    }
+    // In the case of an expanded dimension we are being conservative and
+    // require the smallest reduction stride to be smaller than the maximum row
+    // contiguous size. The reason is that we can't easily know if the reduced
+    // axis is before or after an expanded dimension.
+    if (size > strides.back() || (size == strides.back() && !have_expand)) {
+      return ReductionPlan(GeneralStridedReduce, shape, strides);
+    }
+  }
+
+  return ReductionPlan(GeneralReduce, shape, strides);
+}
+
+} // namespace mlx::core

mlx/backend/common/slicing.cpp

@@ -6,18 +6,16 @@ namespace mlx::core {
 
 std::tuple<bool, int64_t, std::vector<int64_t>> prepare_slice(
     const array& in,
-    std::vector<int>& start_indices,
-    std::vector<int>& strides) {
+    const std::vector<int>& start_indices,
+    const std::vector<int>& strides) {
   int64_t data_offset = 0;
   bool copy_needed = false;
   std::vector<int64_t> inp_strides(in.ndim(), 0);
   for (int i = 0; i < in.ndim(); ++i) {
     data_offset += start_indices[i] * in.strides()[i];
     inp_strides[i] = in.strides()[i] * strides[i];
-
     copy_needed |= strides[i] < 0;
   }
-
   return std::make_tuple(copy_needed, data_offset, inp_strides);
 }
 
@@ -25,26 +23,16 @@ void shared_buffer_slice(
     const array& in,
     const std::vector<size_t>& out_strides,
     size_t data_offset,
+    size_t data_size,
     array& out) {
   // Compute row/col contiguity
-  auto [data_size, is_row_contiguous, is_col_contiguous] =
+  auto [no_bsx_size, is_row_contiguous, is_col_contiguous] =
       check_contiguity(out.shape(), out_strides);
 
   auto flags = in.flags();
   flags.row_contiguous = is_row_contiguous;
   flags.col_contiguous = is_col_contiguous;
-
-  if (data_size == 1) {
-    // Broadcasted scalar array is contiguous.
-    flags.contiguous = true;
-  } else if (data_size == in.data_size()) {
-    // Means we sliced a broadcasted dimension so leave the "no holes" flag
-    // alone.
-  } else {
-    // We sliced something. So either we are row or col contiguous or we
-    // punched a hole.
-    flags.contiguous &= flags.row_contiguous || flags.col_contiguous;
-  }
+  flags.contiguous = (no_bsx_size == data_size);
 
   out.copy_shared_buffer(in, out_strides, flags, data_size, data_offset);
 }

mlx/backend/common/slicing.h

@@ -8,13 +8,14 @@ namespace mlx::core {
 
 std::tuple<bool, int64_t, std::vector<int64_t>> prepare_slice(
     const array& in,
-    std::vector<int>& start_indices,
-    std::vector<int>& strides);
+    const std::vector<int>& start_indices,
+    const std::vector<int>& strides);
 
 void shared_buffer_slice(
     const array& in,
     const std::vector<size_t>& out_strides,
     size_t data_offset,
+    size_t data_size,
     array& out);
 
 } // namespace mlx::core

mlx/backend/common/sort.cpp

@@ -111,26 +111,29 @@ void sort(const array& in, array& out, int axis) {
 
   // Get axis, shape and stride info
   axis = axis < 0 ? axis + in.ndim() : axis;
-  size_t n_rows = in.size() / in.shape(axis);
+  size_t in_size = in.flags().contiguous ? in.data_size() : in.size();
+  size_t n_rows = in_size / in.shape(axis);
 
-  auto remaining_shape = in.shape();
+  auto remaining_shape = out.shape();
   remaining_shape.erase(remaining_shape.begin() + axis);
 
-  auto remaining_strides = in.strides();
+  auto remaining_strides = out.strides();
   remaining_strides.erase(remaining_strides.begin() + axis);
 
-  size_t axis_stride = in.strides()[axis];
-  int axis_size = in.shape(axis);
+  size_t axis_stride = out.strides()[axis];
+  int axis_size = out.shape(axis);
 
   // Perform sorting in place
+  ContiguousIterator<size_t> src_it(
+      remaining_shape, remaining_strides, remaining_shape.size());
   for (int i = 0; i < n_rows; i++) {
-    size_t loc = elem_to_loc(i, remaining_shape, remaining_strides);
-    T* data_ptr = out.data<T>() + loc;
+    T* data_ptr = out.data<T>() + src_it.loc;
 
     StridedIterator st(data_ptr, axis_stride, 0);
     StridedIterator ed(data_ptr, axis_stride, axis_size);
 
     std::stable_sort(st, ed);
+    src_it.step();
   }
 }
 
@@ -143,34 +146,46 @@ void argsort(const array& in, array& out, int axis) {
   axis = axis < 0 ? axis + in.ndim() : axis;
   size_t n_rows = in.size() / in.shape(axis);
 
-  auto remaining_shape = in.shape();
-  remaining_shape.erase(remaining_shape.begin() + axis);
+  auto in_remaining_shape = in.shape();
+  in_remaining_shape.erase(in_remaining_shape.begin() + axis);
 
-  auto remaining_strides = in.strides();
-  remaining_strides.erase(remaining_strides.begin() + axis);
+  auto in_remaining_strides = in.strides();
+  in_remaining_strides.erase(in_remaining_strides.begin() + axis);
 
-  size_t axis_stride = in.strides()[axis];
+  auto out_remaining_shape = out.shape();
+  out_remaining_shape.erase(out_remaining_shape.begin() + axis);
+
+  auto out_remaining_strides = out.strides();
+  out_remaining_strides.erase(out_remaining_strides.begin() + axis);
+
+  size_t in_stride = in.strides()[axis];
+  size_t out_stride = out.strides()[axis];
   int axis_size = in.shape(axis);
 
   // Perform sorting
+  ContiguousIterator<size_t> in_it(
+      in_remaining_shape, in_remaining_strides, in_remaining_shape.size());
+  ContiguousIterator<size_t> out_it(
+      out_remaining_shape, out_remaining_strides, out_remaining_shape.size());
   for (int i = 0; i < n_rows; i++) {
-    size_t loc = elem_to_loc(i, remaining_shape, remaining_strides);
-    const T* data_ptr = in.data<T>() + loc;
-    IdxT* idx_ptr = out.data<IdxT>() + loc;
+    const T* data_ptr = in.data<T>() + in_it.loc;
+    IdxT* idx_ptr = out.data<IdxT>() + out_it.loc;
+    in_it.step();
+    out_it.step();
 
-    StridedIterator st_(idx_ptr, axis_stride, 0);
-    StridedIterator ed_(idx_ptr, axis_stride, axis_size);
+    StridedIterator st_(idx_ptr, out_stride, 0);
+    StridedIterator ed_(idx_ptr, out_stride, axis_size);
 
     // Initialize with iota
     std::iota(st_, ed_, IdxT(0));
 
     // Sort according to vals
-    StridedIterator st(idx_ptr, axis_stride, 0);
-    StridedIterator ed(idx_ptr, axis_stride, axis_size);
+    StridedIterator st(idx_ptr, out_stride, 0);
+    StridedIterator ed(idx_ptr, out_stride, axis_size);
 
-    std::stable_sort(st, ed, [data_ptr, axis_stride](IdxT a, IdxT b) {
-      auto v1 = data_ptr[a * axis_stride];
-      auto v2 = data_ptr[b * axis_stride];
+    std::stable_sort(st, ed, [data_ptr, in_stride](IdxT a, IdxT b) {
+      auto v1 = data_ptr[a * in_stride];
+      auto v2 = data_ptr[b * in_stride];
       return v1 < v2 || (v1 == v2 && a < b);
     });
   }
@@ -184,7 +199,8 @@ void partition(const array& in, array& out, int axis, int kth) {
 
   // Get axis, shape and stride info
   axis = axis < 0 ? axis + in.ndim() : axis;
-  size_t n_rows = in.size() / in.shape(axis);
+  size_t in_size = in.flags().contiguous ? in.data_size() : in.size();
+  size_t n_rows = in_size / in.shape(axis);
 
   auto remaining_shape = in.shape();
   remaining_shape.erase(remaining_shape.begin() + axis);
@@ -198,9 +214,11 @@ void partition(const array& in, array& out, int axis, int kth) {
   kth = kth < 0 ? kth + axis_size : kth;
 
   // Perform partition in place
+  ContiguousIterator<size_t> src_it(
+      remaining_shape, remaining_strides, remaining_shape.size());
   for (int i = 0; i < n_rows; i++) {
-    size_t loc = elem_to_loc(i, remaining_shape, remaining_strides);
-    T* data_ptr = out.data<T>() + loc;
+    T* data_ptr = out.data<T>() + src_it.loc;
+    src_it.step();
 
     StridedIterator st(data_ptr, axis_stride, 0);
     StridedIterator md(data_ptr, axis_stride, kth);
@@ -219,37 +237,49 @@ void argpartition(const array& in, array& out, int axis, int kth) {
   axis = axis < 0 ? axis + in.ndim() : axis;
   size_t n_rows = in.size() / in.shape(axis);
 
-  auto remaining_shape = in.shape();
-  remaining_shape.erase(remaining_shape.begin() + axis);
+  auto in_remaining_shape = in.shape();
+  in_remaining_shape.erase(in_remaining_shape.begin() + axis);
 
-  auto remaining_strides = in.strides();
-  remaining_strides.erase(remaining_strides.begin() + axis);
+  auto in_remaining_strides = in.strides();
+  in_remaining_strides.erase(in_remaining_strides.begin() + axis);
 
-  size_t axis_stride = in.strides()[axis];
+  auto out_remaining_shape = out.shape();
+  out_remaining_shape.erase(out_remaining_shape.begin() + axis);
+
+  auto out_remaining_strides = out.strides();
+  out_remaining_strides.erase(out_remaining_strides.begin() + axis);
+
+  size_t in_stride = in.strides()[axis];
+  size_t out_stride = out.strides()[axis];
   int axis_size = in.shape(axis);
 
   kth = kth < 0 ? kth + axis_size : kth;
 
   // Perform partition
+  ContiguousIterator<size_t> in_it(
+      in_remaining_shape, in_remaining_strides, in_remaining_shape.size());
+  ContiguousIterator<size_t> out_it(
+      out_remaining_shape, out_remaining_strides, out_remaining_shape.size());
   for (int i = 0; i < n_rows; i++) {
-    size_t loc = elem_to_loc(i, remaining_shape, remaining_strides);
-    const T* data_ptr = in.data<T>() + loc;
-    IdxT* idx_ptr = out.data<IdxT>() + loc;
+    const T* data_ptr = in.data<T>() + in_it.loc;
+    IdxT* idx_ptr = out.data<IdxT>() + out_it.loc;
+    in_it.step();
+    out_it.step();
 
-    StridedIterator st_(idx_ptr, axis_stride, 0);
-    StridedIterator ed_(idx_ptr, axis_stride, axis_size);
+    StridedIterator st_(idx_ptr, out_stride, 0);
+    StridedIterator ed_(idx_ptr, out_stride, axis_size);
 
     // Initialize with iota
     std::iota(st_, ed_, IdxT(0));
 
     // Sort according to vals
-    StridedIterator st(idx_ptr, axis_stride, 0);
-    StridedIterator md(idx_ptr, axis_stride, kth);
-    StridedIterator ed(idx_ptr, axis_stride, axis_size);
+    StridedIterator st(idx_ptr, out_stride, 0);
+    StridedIterator md(idx_ptr, out_stride, kth);
+    StridedIterator ed(idx_ptr, out_stride, axis_size);
 
-    std::nth_element(st, md, ed, [data_ptr, axis_stride](IdxT a, IdxT b) {
-      auto v1 = data_ptr[a * axis_stride];
-      auto v2 = data_ptr[b * axis_stride];
+    std::nth_element(st, md, ed, [data_ptr, in_stride](IdxT a, IdxT b) {
+      auto v1 = data_ptr[a * in_stride];
+      auto v2 = data_ptr[b * in_stride];
       return v1 < v2 || (v1 == v2 && a < b);
     });
   }

mlx/backend/common/ternary.h

@@ -12,6 +12,7 @@ namespace {
 // TODO: Add support for more combinations of input types.
 enum class TernaryOpType {
   ScalarScalarScalar,
+  VectorVectorVector,
   General,
 };
 
@@ -20,6 +21,12 @@ get_ternary_op_type(const array& a, const array& b, const array& c) {
   TernaryOpType topt;
   if (a.data_size() == 1 && b.data_size() == 1 && c.data_size() == 1) {
     topt = TernaryOpType::ScalarScalarScalar;
+  } else if (
+      (a.flags().row_contiguous && b.flags().row_contiguous &&
+       c.flags().row_contiguous) ||
+      (a.flags().col_contiguous && b.flags().col_contiguous &&
+       c.flags().col_contiguous)) {
+    topt = TernaryOpType::VectorVectorVector;
   } else {
     topt = TernaryOpType::General;
   }
@@ -33,138 +40,77 @@ void set_ternary_op_output_data(
     array& out,
     TernaryOpType topt,
     bool donate_with_move = false) {
+  auto maybe_donate = [&out, donate_with_move](const array& x) {
+    if (is_donatable(x, out)) {
+      if (donate_with_move) {
+        out.move_shared_buffer(x);
+      } else {
+        out.copy_shared_buffer(x);
+      }
+      return true;
+    }
+    return false;
+  };
+
   switch (topt) {
     case TernaryOpType::ScalarScalarScalar:
       out.set_data(
           allocator::malloc_or_wait(out.itemsize()), 1, b.strides(), b.flags());
       break;
+    case TernaryOpType::VectorVectorVector:
+      if (!(maybe_donate(a) || maybe_donate(b) || maybe_donate(c))) {
+        out.set_data(
+            allocator::malloc_or_wait(out.itemsize() * b.data_size()),
+            b.data_size(),
+            b.strides(),
+            b.flags());
+      }
+      break;
     case TernaryOpType::General:
       out.set_data(allocator::malloc_or_wait(out.nbytes()));
       break;
   }
 }
+template <typename T1, typename T2, typename T3, typename U, typename Op, int D>
+void ternary_op_dims(
+    const T1* a,
+    const T2* b,
+    const T3* c,
+    U* out,
+    Op op,
+    const std::vector<int>& shape,
+    const std::vector<size_t>& a_strides,
+    const std::vector<size_t>& b_strides,
+    const std::vector<size_t>& c_strides,
+    const std::vector<size_t>& out_strides,
+    int axis) {
+  auto stride_a = a_strides[axis];
+  auto stride_b = b_strides[axis];
+  auto stride_c = c_strides[axis];
+  auto stride_out = out_strides[axis];
+  auto N = shape[axis];
 
-template <typename T1, typename T2, typename T3, typename U, typename Op>
-void ternary_op_dims1(
-    const array& a,
-    const array& b,
-    const array& c,
-    array& out,
-    Op op) {
-  const T1* a_ptr = a.data<T1>();
-  const T2* b_ptr = b.data<T2>();
-  const T3* c_ptr = c.data<T3>();
-
-  U* dst = out.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  size_t c_idx = 0;
-  for (size_t i = 0; i < out.size(); ++i) {
-    dst[i] = op(a_ptr[a_idx], b_ptr[b_idx], c_ptr[c_idx]);
-    a_idx += a.strides()[0];
-    b_idx += b.strides()[0];
-    c_idx += c.strides()[0];
-  }
-}
-
-template <typename T1, typename T2, typename T3, typename U, typename Op>
-void ternary_op_dims2(
-    const array& a,
-    const array& b,
-    const array& c,
-    array& out,
-    Op op) {
-  const T1* a_ptr = a.data<T1>();
-  const T2* b_ptr = b.data<T2>();
-  const T3* c_ptr = c.data<T3>();
-
-  U* dst = out.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  size_t c_idx = 0;
-  size_t out_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; ++i) {
-    for (size_t j = 0; j < a.shape()[1]; ++j) {
-      dst[out_idx++] = op(a_ptr[a_idx], b_ptr[b_idx], c_ptr[c_idx]);
-      a_idx += a.strides()[1];
-      b_idx += b.strides()[1];
-      c_idx += c.strides()[1];
+  for (int i = 0; i < N; i++) {
+    if constexpr (D > 1) {
+      ternary_op_dims<T1, T2, T3, U, Op, D - 1>(
+          a,
+          b,
+          c,
+          out,
+          op,
+          shape,
+          a_strides,
+          b_strides,
+          c_strides,
+          out_strides,
+          axis + 1);
+    } else {
+      *out = op(*a, *b, *c);
     }
-    a_idx += a.strides()[0] - a.strides()[1] * a.shape()[1];
-    b_idx += b.strides()[0] - b.strides()[1] * b.shape()[1];
-    c_idx += c.strides()[0] - c.strides()[1] * c.shape()[1];
-  }
-}
-
-template <typename T1, typename T2, typename T3, typename U, typename Op>
-void ternary_op_dims3(
-    const array& a,
-    const array& b,
-    const array& c,
-    array& out,
-    Op op) {
-  const T1* a_ptr = a.data<T1>();
-  const T2* b_ptr = b.data<T2>();
-  const T3* c_ptr = c.data<T3>();
-  U* dst = out.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  size_t c_idx = 0;
-  size_t out_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; ++i) {
-    for (size_t j = 0; j < a.shape()[1]; ++j) {
-      for (size_t k = 0; k < a.shape()[2]; ++k) {
-        dst[out_idx++] = op(a_ptr[a_idx], b_ptr[b_idx], c_ptr[c_idx]);
-        a_idx += a.strides()[2];
-        b_idx += b.strides()[2];
-        c_idx += c.strides()[2];
-      }
-      a_idx += a.strides()[1] - a.strides()[2] * a.shape()[2];
-      b_idx += b.strides()[1] - b.strides()[2] * b.shape()[2];
-      c_idx += c.strides()[1] - c.strides()[2] * c.shape()[2];
-    }
-    a_idx += a.strides()[0] - a.strides()[1] * a.shape()[1];
-    b_idx += b.strides()[0] - b.strides()[1] * b.shape()[1];
-    c_idx += c.strides()[0] - c.strides()[1] * c.shape()[1];
-  }
-}
-
-template <typename T1, typename T2, typename T3, typename U, typename Op>
-void ternary_op_dims4(
-    const array& a,
-    const array& b,
-    const array& c,
-    array& out,
-    Op op) {
-  const T1* a_ptr = a.data<T1>();
-  const T2* b_ptr = b.data<T2>();
-  const T3* c_ptr = c.data<T3>();
-
-  U* dst = out.data<U>();
-  size_t a_idx = 0;
-  size_t b_idx = 0;
-  size_t c_idx = 0;
-  size_t out_idx = 0;
-  for (size_t i = 0; i < a.shape()[0]; ++i) {
-    for (size_t j = 0; j < a.shape()[1]; ++j) {
-      for (size_t k = 0; k < a.shape()[2]; ++k) {
-        for (size_t ii = 0; ii < a.shape()[3]; ++ii) {
-          dst[out_idx++] = op(a_ptr[a_idx], b_ptr[b_idx], c_ptr[c_idx]);
-          a_idx += a.strides()[3];
-          b_idx += b.strides()[3];
-          c_idx += c.strides()[3];
-        }
-        a_idx += a.strides()[2] - a.strides()[3] * a.shape()[3];
-        b_idx += b.strides()[2] - b.strides()[3] * b.shape()[3];
-        c_idx += c.strides()[2] - c.strides()[3] * c.shape()[3];
-      }
-      a_idx += a.strides()[1] - a.strides()[2] * a.shape()[2];
-      b_idx += b.strides()[1] - b.strides()[2] * b.shape()[2];
-      c_idx += c.strides()[1] - c.strides()[2] * c.shape()[2];
-    }
-    a_idx += a.strides()[0] - a.strides()[1] * a.shape()[1];
-    b_idx += b.strides()[0] - b.strides()[1] * b.shape()[1];
-    c_idx += c.strides()[0] - c.strides()[1] * c.shape()[1];
+    a += stride_a;
+    b += stride_b;
+    c += stride_c;
+    out += stride_out;
   }
 }
 
@@ -175,30 +121,69 @@ void ternary_op_dispatch_dims(
     const array& c,
     array& out,
     Op op) {
-  switch (out.ndim()) {
-    case 1:
-      ternary_op_dims1<T1, T2, T3, U, Op>(a, b, c, out, op);
-      return;
-    case 2:
-      ternary_op_dims2<T1, T2, T3, U, Op>(a, b, c, out, op);
-      return;
-    case 3:
-      ternary_op_dims3<T1, T2, T3, U, Op>(a, b, c, out, op);
-      return;
-    case 4:
-      ternary_op_dims4<T1, T2, T3, U, Op>(a, b, c, out, op);
-      return;
-  }
+  auto [shape, strides] = collapse_contiguous_dims(
+      a.shape(), {a.strides(), b.strides(), c.strides(), out.strides()});
+  const auto& a_strides = strides[0];
+  const auto& b_strides = strides[1];
+  const auto& c_strides = strides[2];
+  const auto& out_strides = strides[3];
 
   const T1* a_ptr = a.data<T1>();
   const T2* b_ptr = b.data<T2>();
   const T3* c_ptr = c.data<T3>();
-  U* dst = out.data<U>();
-  for (size_t i = 0; i < out.size(); i++) {
-    int a_idx = elem_to_loc(i, a.shape(), a.strides());
-    int b_idx = elem_to_loc(i, b.shape(), b.strides());
-    int c_idx = elem_to_loc(i, c.shape(), c.strides());
-    dst[i] = op(a_ptr[a_idx], b_ptr[b_idx], c_ptr[c_idx]);
+  U* out_ptr = out.data<T3>();
+  int ndim = shape.size();
+  switch (ndim) {
+    case 1:
+      ternary_op_dims<T1, T2, T3, U, Op, 1>(
+          a_ptr,
+          b_ptr,
+          c_ptr,
+          out_ptr,
+          op,
+          shape,
+          a_strides,
+          b_strides,
+          c_strides,
+          out_strides,
+          0);
+      return;
+    case 2:
+      ternary_op_dims<T1, T2, T3, U, Op, 2>(
+          a_ptr,
+          b_ptr,
+          c_ptr,
+          out_ptr,
+          op,
+          shape,
+          a_strides,
+          b_strides,
+          c_strides,
+          out_strides,
+          0);
+      return;
+  }
+
+  ContiguousIterator<size_t> a_it(shape, a_strides, ndim - 2);
+  ContiguousIterator<size_t> b_it(shape, b_strides, ndim - 2);
+  ContiguousIterator<size_t> c_it(shape, c_strides, ndim - 2);
+  size_t stride = out_strides[ndim - 3];
+  for (size_t elem = 0; elem < a.size(); elem += stride) {
+    ternary_op_dims<T1, T2, T3, U, Op, 2>(
+        a_ptr + a_it.loc,
+        b_ptr + b_it.loc,
+        c_ptr + c_it.loc,
+        out_ptr + elem,
+        op,
+        shape,
+        a_strides,
+        b_strides,
+        c_strides,
+        out_strides,
+        ndim - 2);
+    a_it.step();
+    b_it.step();
+    c_it.step();
   }
 }
 
@@ -215,10 +200,21 @@ void ternary_op(
   // The full computation is scalar-scalar-scalar so we call the base op once.
   if (topt == TernaryOpType::ScalarScalarScalar) {
     *(out.data<U>()) = op(*a.data<T1>(), *b.data<T2>(), *c.data<T3>());
-    return;
+  } else if (topt == TernaryOpType::VectorVectorVector) {
+    const T1* a_ptr = a.data<T1>();
+    const T2* b_ptr = b.data<T2>();
+    const T3* c_ptr = c.data<T3>();
+    U* out_ptr = out.data<U>();
+    for (size_t i = 0; i < out.size(); ++i) {
+      *out_ptr = op(*a_ptr, *b_ptr, *c_ptr);
+      a_ptr++;
+      b_ptr++;
+      c_ptr++;
+      out_ptr++;
+    }
+  } else {
+    ternary_op_dispatch_dims<T1, T2, T3, U>(a, b, c, out, op);
   }
-
-  ternary_op_dispatch_dims<T1, T2, T3, U>(a, b, c, out, op);
 }
 
 } // namespace

mlx/backend/common/unary.h

@@ -12,7 +12,7 @@ namespace mlx::core {
 namespace {
 
 void set_unary_output_data(const array& in, array& out) {
-  if (in.is_donatable() && in.itemsize() == out.itemsize()) {
+  if (is_donatable(in, out)) {
     out.copy_shared_buffer(in);
   } else {
     auto size = in.data_size();
@@ -24,6 +24,14 @@ void set_unary_output_data(const array& in, array& out) {
   }
 }
 
+template <typename T, typename Op>
+void unary_op(const T* a, T* out, Op op, size_t shape, size_t stride) {
+  for (size_t i = 0; i < shape; i += 1) {
+    out[i] = op(*a);
+    a += stride;
+  }
+}
+
 template <typename T, typename Op>
 void unary_op(const array& a, array& out, Op op) {
   const T* a_ptr = a.data<T>();
@@ -36,10 +44,16 @@ void unary_op(const array& a, array& out, Op op) {
   } else {
     out.set_data(allocator::malloc_or_wait(out.nbytes()));
     T* dst = out.data<T>();
-    for (size_t i = 0; i < out.size(); ++i) {
-      // TODO this is super inefficient, need to fix.
-      int a_idx = elem_to_loc(i, a.shape(), a.strides());
-      dst[i] = op(a_ptr[a_idx]);
+    size_t shape = a.ndim() > 0 ? a.shape(-1) : 1;
+    size_t stride = a.ndim() > 0 ? a.strides(-1) : 1;
+    if (a.ndim() <= 1) {
+      unary_op(a_ptr, dst, op, shape, stride);
+      return;
+    }
+    ContiguousIterator it(a.shape(), a.strides(), a.ndim() - 1);
+    for (size_t elem = 0; elem < a.size(); elem += shape) {
+      unary_op(a_ptr + it.loc, dst + elem, op, shape, stride);
+      it.step();
     }
   }
 }

mlx/backend/common/utils.cpp

@@ -0,0 +1,138 @@
+// Copyright © 2023-2024 Apple Inc.
+
+#include "mlx/backend/common/utils.h"
+
+namespace mlx::core {
+
+template <typename StrideT>
+std::tuple<std::vector<int>, std::vector<std::vector<StrideT>>>
+collapse_contiguous_dims_impl(
+    const std::vector<int>& shape,
+    const std::vector<std::vector<StrideT>>& strides,
+    StrideT size_cap) {
+  // Make a vector that has axes separated with -1. Collapse all axes between
+  // -1.
+  std::vector<int> to_collapse;
+  if (shape.size() > 0) {
+    if (shape[0] != 1) {
+      to_collapse.push_back(0);
+    }
+    size_t size = shape[0];
+    for (int i = 1; i < shape.size(); i++) {
+      bool contiguous = true;
+      size *= shape[i];
+      for (const std::vector<StrideT>& st : strides) {
+        if (st[i] * shape[i] != st[i - 1] || size > size_cap) {
+          contiguous = false;
+          size = shape[i];
+          break;
+        }
+      }
+      if (!contiguous) {
+        to_collapse.push_back(-1);
+      }
+      if (shape[i] != 1) {
+        to_collapse.push_back(i);
+      }
+    }
+    to_collapse.push_back(-1);
+  }
+
+  std::vector<int> out_shape;
+  std::vector<std::vector<StrideT>> out_strides(strides.size());
+  for (int i = 0;;) {
+    while (i < to_collapse.size() && to_collapse[i] == -1) {
+      ++i;
+    };
+    if (i == to_collapse.size()) {
+      break;
+    }
+    int current_shape = shape[to_collapse[i]];
+    int k = i;
+    while (to_collapse[++k] != -1) {
+      current_shape *= shape[to_collapse[k]];
+    }
+    out_shape.push_back(current_shape);
+    for (int j = 0; j < strides.size(); j++) {
+      const std::vector<StrideT>& st = strides[j];
+      out_strides[j].push_back(st[to_collapse[k - 1]]);
+    }
+    i = k + 1;
+  }
+
+  if (!shape.empty() && out_shape.empty()) {
+    out_shape.push_back(1);
+    for (auto& out_stride : out_strides) {
+      out_stride.push_back(0);
+    }
+  }
+  return std::make_tuple(out_shape, out_strides);
+}
+
+std::tuple<std::vector<int>, std::vector<std::vector<int64_t>>>
+collapse_contiguous_dims(
+    const std::vector<int>& shape,
+    const std::vector<std::vector<int64_t>>& strides,
+    int64_t size_cap /* = std::numeric_limits<int32_t>::max() */) {
+  return collapse_contiguous_dims_impl(shape, strides, size_cap);
+}
+
+std::tuple<std::vector<int>, std::vector<std::vector<size_t>>>
+collapse_contiguous_dims(
+    const std::vector<int>& shape,
+    const std::vector<std::vector<size_t>>& strides,
+    size_t size_cap /* = std::numeric_limits<int32>::max() */) {
+  return collapse_contiguous_dims_impl(shape, strides, size_cap);
+}
+
+template <typename StrideT>
+std::pair<std::vector<int>, std::vector<StrideT>> collapse_contiguous_dims_impl(
+    const std::vector<int>& shape,
+    const std::vector<StrideT>& strides,
+    StrideT size_cap) {
+  std::vector<int> collapsed_shape;
+  std::vector<StrideT> collapsed_strides;
+
+  if (shape.size() > 0) {
+    collapsed_shape.push_back(shape[0]);
+    collapsed_strides.push_back(strides[0]);
+    for (int i = 1; i < shape.size(); i++) {
+      if (shape[i] == 1) {
+        continue;
+      } else if (
+          strides[i] * shape[i] != collapsed_strides.back() ||
+          collapsed_shape.back() * static_cast<StrideT>(shape[i]) > size_cap) {
+        collapsed_shape.push_back(shape[i]);
+        collapsed_strides.push_back(strides[i]);
+      } else {
+        collapsed_shape.back() *= shape[i];
+        collapsed_strides.back() = strides[i];
+      }
+    }
+  }
+
+  return std::make_pair(collapsed_shape, collapsed_strides);
+}
+
+std::pair<std::vector<int>, std::vector<int64_t>> collapse_contiguous_dims(
+    const std::vector<int>& shape,
+    const std::vector<int64_t>& strides,
+    int64_t size_cap /* = std::numeric_limits<int32_t>::max() */) {
+  return collapse_contiguous_dims_impl<int64_t>(shape, strides, size_cap);
+}
+
+std::pair<std::vector<int>, std::vector<size_t>> collapse_contiguous_dims(
+    const std::vector<int>& shape,
+    const std::vector<size_t>& strides,
+    size_t size_cap /* = std::numeric_limits<int32_t>::max() */) {
+  return collapse_contiguous_dims_impl<size_t>(shape, strides, size_cap);
+}
+
+std::pair<std::vector<int>, std::vector<size_t>> collapse_contiguous_dims(
+    const array& a,
+    size_t size_cap /* = std::numeric_limits<int32_t>::max()*/) {
+  return collapse_contiguous_dims_impl<size_t>(
+      a.shape(), a.strides(), size_cap);
+}
+
+} // namespace mlx::core

mlx/backend/common/utils.h

@@ -8,12 +8,12 @@
 
 namespace mlx::core {
 
-template <typename stride_t>
-inline stride_t elem_to_loc(
+template <typename StrideT>
+inline StrideT elem_to_loc(
     int elem,
     const std::vector<int>& shape,
-    const std::vector<stride_t>& strides) {
-  stride_t loc = 0;
+    const std::vector<StrideT>& strides) {
+  StrideT loc = 0;
   for (int i = shape.size() - 1; i >= 0; --i) {
     auto q_and_r = ldiv(elem, shape[i]);
     loc += q_and_r.rem * strides[i];
@@ -29,64 +29,41 @@ inline size_t elem_to_loc(int elem, const array& a) {
   return elem_to_loc(elem, a.shape(), a.strides());
 }
 
+template <typename StrideT>
+std::vector<StrideT> make_contiguous_strides(const std::vector<int>& shape) {
+  std::vector<StrideT> strides(shape.size(), 1);
+  for (int i = shape.size() - 1; i > 0; i--) {
+    strides[i - 1] = strides[i] * shape[i];
+  }
+  return strides;
+}
+
 // Collapse dims that are contiguous to possibly route to a better kernel
 // e.g. for x = transpose(array({0, 1, 2, 3, 4, 5, 6, 7}, {2, 2, 2}), {2, 0, 1})
 // should return {{2, 4}, {{1, 2}}}.
 //
 // When multiple arrays are passed they should all have the same shape. The
 // collapsed axes are also the same so one shape is returned.
-template <typename stride_t>
-inline std::tuple<std::vector<int>, std::vector<std::vector<stride_t>>>
+std::tuple<std::vector<int>, std::vector<std::vector<int64_t>>>
 collapse_contiguous_dims(
     const std::vector<int>& shape,
-    const std::vector<std::vector<stride_t>> strides) {
-  // Make a vector that has axes separated with -1. Collapse all axes between
-  // -1.
-  std::vector<int> to_collapse;
-  if (shape.size() > 0) {
-    to_collapse.push_back(0);
-    for (int i = 1; i < shape.size(); i++) {
-      bool contiguous = true;
-      for (const std::vector<stride_t>& st : strides) {
-        if (st[i] * shape[i] != st[i - 1]) {
-          contiguous = false;
-        }
-        if (!contiguous) {
-          break;
-        }
-      }
-      if (!contiguous) {
-        to_collapse.push_back(-1);
-      }
-      to_collapse.push_back(i);
-    }
-    to_collapse.push_back(-1);
-  }
-
-  std::vector<int> out_shape;
-  std::vector<std::vector<stride_t>> out_strides(strides.size());
-  for (int i = 0; i < to_collapse.size(); i++) {
-    int current_shape = shape[to_collapse[i]];
-    while (to_collapse[++i] != -1) {
-      current_shape *= shape[to_collapse[i]];
-    }
-    out_shape.push_back(current_shape);
-    for (int j = 0; j < strides.size(); j++) {
-      const std::vector<stride_t>& st = strides[j];
-      out_strides[j].push_back(st[to_collapse[i - 1]]);
-    }
-  }
-
-  return std::make_tuple(out_shape, out_strides);
-}
+    const std::vector<std::vector<int64_t>>& strides,
+    int64_t size_cap = std::numeric_limits<int32_t>::max());
+std::tuple<std::vector<int>, std::vector<std::vector<size_t>>>
+collapse_contiguous_dims(
+    const std::vector<int>& shape,
+    const std::vector<std::vector<size_t>>& strides,
+    size_t size_cap = std::numeric_limits<int32_t>::max());
 
 inline std::tuple<std::vector<int>, std::vector<std::vector<size_t>>>
-collapse_contiguous_dims(const std::vector<array>& xs) {
+collapse_contiguous_dims(
+    const std::vector<array>& xs,
+    size_t size_cap = std::numeric_limits<int32_t>::max()) {
   std::vector<std::vector<size_t>> strides;
   for (auto& x : xs) {
     strides.emplace_back(x.strides());
   }
-  return collapse_contiguous_dims(xs[0].shape(), strides);
+  return collapse_contiguous_dims(xs[0].shape(), strides, size_cap);
 }
 
 template <typename... Arrays, typename = enable_for_arrays_t<Arrays...>>
@@ -95,27 +72,110 @@ inline auto collapse_contiguous_dims(Arrays&&... xs) {
       std::vector<array>{std::forward<Arrays>(xs)...});
 }
 
-template <typename stride_t>
+// The single array version of the above.
+std::pair<std::vector<int>, std::vector<int64_t>> collapse_contiguous_dims(
+    const std::vector<int>& shape,
+    const std::vector<int64_t>& strides,
+    int64_t size_cap = std::numeric_limits<int32_t>::max());
+std::pair<std::vector<int>, std::vector<size_t>> collapse_contiguous_dims(
+    const std::vector<int>& shape,
+    const std::vector<size_t>& strides,
+    size_t size_cap = std::numeric_limits<int32_t>::max());
+std::pair<std::vector<int>, std::vector<size_t>> collapse_contiguous_dims(
+    const array& a,
+    size_t size_cap = std::numeric_limits<int32_t>::max());
+
+template <typename StrideT>
+struct ContiguousIterator {
+  inline void step() {
+    int dims = shape_.size();
+    if (dims == 0) {
+      return;
+    }
+    int i = dims - 1;
+    while (pos_[i] == (shape_[i] - 1) && i > 0) {
+      pos_[i] = 0;
+      loc -= (shape_[i] - 1) * strides_[i];
+      i--;
+    }
+    pos_[i]++;
+    loc += strides_[i];
+  }
+
+  void seek(StrideT n) {
+    loc = 0;
+    for (int i = shape_.size() - 1; i >= 0; --i) {
+      auto q_and_r = ldiv(n, shape_[i]);
+      loc += q_and_r.rem * strides_[i];
+      pos_[i] = q_and_r.rem;
+      n = q_and_r.quot;
+    }
+  }
+
+  void reset() {
+    loc = 0;
+    std::fill(pos_.begin(), pos_.end(), 0);
+  }
+
+  ContiguousIterator() {};
+
+  explicit ContiguousIterator(const array& a)
+      : shape_(a.shape()), strides_(a.strides()) {
+    if (!shape_.empty()) {
+      std::tie(shape_, strides_) = collapse_contiguous_dims(shape_, strides_);
+      pos_ = std::vector<int>(shape_.size(), 0);
+    }
+  }
+
+  explicit ContiguousIterator(
+      const std::vector<int>& shape,
+      const std::vector<StrideT>& strides,
+      int dims)
+      : shape_(shape.begin(), shape.begin() + dims),
+        strides_(strides.begin(), strides.begin() + dims) {
+    if (!shape_.empty()) {
+      std::tie(shape_, strides_) = collapse_contiguous_dims(shape_, strides_);
+      pos_ = std::vector<int>(shape_.size(), 0);
+    }
+  }
+
+  StrideT loc{0};
+
+ private:
+  std::vector<int> shape_;
+  std::vector<StrideT> strides_;
+  std::vector<int> pos_;
+};
+
+template <typename StrideT>
 inline auto check_contiguity(
     const std::vector<int>& shape,
-    const std::vector<stride_t>& strides) {
-  size_t data_size = 1;
+    const std::vector<StrideT>& strides) {
+  size_t no_broadcast_data_size = 1;
   size_t f_stride = 1;
   size_t b_stride = 1;
   bool is_row_contiguous = true;
   bool is_col_contiguous = true;
 
   for (int i = 0, ri = shape.size() - 1; ri >= 0; i++, ri--) {
-    is_row_contiguous &= strides[i] == f_stride || shape[i] == 1;
-    is_col_contiguous &= strides[ri] == b_stride || shape[ri] == 1;
+    is_col_contiguous &= strides[i] == f_stride || shape[i] == 1;
+    is_row_contiguous &= strides[ri] == b_stride || shape[ri] == 1;
     f_stride *= shape[i];
     b_stride *= shape[ri];
     if (strides[i] > 0) {
-      data_size *= shape[i];
+      no_broadcast_data_size *= shape[i];
     }
   }
 
-  return std::make_tuple(data_size, is_row_contiguous, is_col_contiguous);
+  return std::make_tuple(
+      no_broadcast_data_size, is_row_contiguous, is_col_contiguous);
+}
+
+inline bool is_donatable(const array& in, const array& out) {
+  constexpr size_t donation_extra = 16384;
+
+  return in.is_donatable() && in.itemsize() == out.itemsize() &&
+      in.buffer_size() <= out.nbytes() + donation_extra;
 }
 
 } // namespace mlx::core

mlx/backend/metal/CMakeLists.txt

@@ -1,97 +1,56 @@
 function(make_jit_source SRC_FILE)
-  # This function takes a metal header file,
-  # runs the C preprocessesor on it, and makes
-  # the processed contents available as a string in a C++ function
+  # This function takes a metal header file, runs the C preprocessesor on it,
+  # and makes the processed contents available as a string in a C++ function
   # mlx::core::metal::${SRC_NAME}()
   #
-  # To use the function, declare it in jit/includes.h and
-  # include jit/includes.h.
+  # To use the function, declare it in jit/includes.h and include
+  # jit/includes.h.
   #
-  # Additional arguments to this function are treated as dependencies
-  # in the Cmake build system.
+  # Additional arguments to this function are treated as dependencies in the
+  # Cmake build system.
   get_filename_component(SRC_NAME ${SRC_FILE} NAME)
   add_custom_command(
-    OUTPUT  jit/${SRC_NAME}.cpp
-    COMMAND /bin/bash
-              ${CMAKE_CURRENT_SOURCE_DIR}/make_compiled_preamble.sh
-              ${CMAKE_CURRENT_BINARY_DIR}/jit
-              ${CMAKE_C_COMPILER}
-              ${PROJECT_SOURCE_DIR}
-              ${SRC_FILE}
-              "-D${MLX_METAL_VERSION}"
-    DEPENDS make_compiled_preamble.sh
-            kernels/${SRC_FILE}.h
-            ${ARGN}
-  )
+    OUTPUT jit/${SRC_NAME}.cpp
+    COMMAND
+      /bin/bash ${CMAKE_CURRENT_SOURCE_DIR}/make_compiled_preamble.sh
+      ${CMAKE_CURRENT_BINARY_DIR}/jit ${CMAKE_C_COMPILER} ${PROJECT_SOURCE_DIR}
+      ${SRC_FILE} "-DMLX_METAL_VERSION=${MLX_METAL_VERSION}"
+    DEPENDS make_compiled_preamble.sh kernels/${SRC_FILE}.h ${ARGN})
   add_custom_target(${SRC_NAME} DEPENDS jit/${SRC_NAME}.cpp)
   add_dependencies(mlx ${SRC_NAME})
-  target_sources(
-    mlx
-    PRIVATE
-    ${CMAKE_CURRENT_BINARY_DIR}/jit/${SRC_NAME}.cpp
-  )
+  target_sources(mlx PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/jit/${SRC_NAME}.cpp)
 endfunction(make_jit_source)
 
-make_jit_source(
-  utils
-  kernels/bf16.h
-  kernels/complex.h
-  kernels/defines.h
-)
-make_jit_source(
-  unary_ops
-  kernels/erf.h
-  kernels/expm1f.h
-)
+make_jit_source(utils kernels/bf16.h kernels/complex.h kernels/defines.h)
+make_jit_source(unary_ops kernels/erf.h kernels/expm1f.h)
 make_jit_source(binary_ops)
 make_jit_source(ternary_ops)
-make_jit_source(
-  reduce_utils
-  kernels/atomic.h
-  kernels/reduction/ops.h
-)
+make_jit_source(reduce_utils kernels/atomic.h kernels/reduction/ops.h)
 make_jit_source(scatter)
 make_jit_source(gather)
+make_jit_source(hadamard)
 
-if (MLX_METAL_JIT) 
-  target_sources(
-    mlx
-    PRIVATE
-    ${CMAKE_CURRENT_SOURCE_DIR}/jit_kernels.cpp
-  )
+if(MLX_METAL_JIT)
+  target_sources(mlx PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/jit_kernels.cpp)
   make_jit_source(arange)
   make_jit_source(copy)
   make_jit_source(unary)
   make_jit_source(binary)
   make_jit_source(binary_two)
-  make_jit_source(
-    fft
-    kernels/fft/radix.h
-    kernels/fft/readwrite.h
-  )
+  make_jit_source(fft kernels/fft/radix.h kernels/fft/readwrite.h)
   make_jit_source(ternary)
   make_jit_source(softmax)
   make_jit_source(scan)
   make_jit_source(sort)
   make_jit_source(
-    reduce
-    kernels/reduction/reduce_all.h
-    kernels/reduction/reduce_col.h
-    kernels/reduction/reduce_row.h
-  )
+    reduce kernels/reduction/reduce_all.h kernels/reduction/reduce_col.h
+    kernels/reduction/reduce_row.h kernels/reduction/reduce_init.h)
   make_jit_source(
-    steel/gemm/gemm
-    kernels/steel/utils.h
-    kernels/steel/gemm/loader.h
-    kernels/steel/gemm/mma.h
-    kernels/steel/gemm/params.h
-    kernels/steel/gemm/transforms.h
-  )
+    steel/gemm/gemm kernels/steel/utils.h kernels/steel/gemm/loader.h
+    kernels/steel/gemm/mma.h kernels/steel/gemm/params.h
+    kernels/steel/gemm/transforms.h)
   make_jit_source(steel/gemm/kernels/steel_gemm_fused)
-  make_jit_source(
-    steel/gemm/kernels/steel_gemm_masked
-    kernels/steel/defines.h
-  )
+  make_jit_source(steel/gemm/kernels/steel_gemm_masked kernels/steel/defines.h)
   make_jit_source(steel/gemm/kernels/steel_gemm_splitk)
   make_jit_source(
     steel/conv/conv
@@ -102,57 +61,51 @@ if (MLX_METAL_JIT)
     kernels/steel/conv/params.h
     kernels/steel/conv/loader.h
     kernels/steel/conv/loaders/loader_channel_l.h
-    kernels/steel/conv/loaders/loader_channel_n.h
-  )
-  make_jit_source(
-    steel/conv/kernels/steel_conv
-  )
-  make_jit_source(
-    steel/conv/kernels/steel_conv_general
-    kernels/steel/defines.h
-    kernels/steel/conv/loaders/loader_general.h
-  )
+    kernels/steel/conv/loaders/loader_channel_n.h)
+  make_jit_source(steel/conv/kernels/steel_conv)
+  make_jit_source(steel/conv/kernels/steel_conv_general kernels/steel/defines.h
+                  kernels/steel/conv/loaders/loader_general.h)
+  make_jit_source(quantized)
+  make_jit_source(gemv_masked)
 else()
-  target_sources(
-    mlx
-    PRIVATE
-    ${CMAKE_CURRENT_SOURCE_DIR}/nojit_kernels.cpp
-  )
+  target_sources(mlx PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/nojit_kernels.cpp)
 endif()
 
 target_sources(
   mlx
-  PRIVATE
-  ${CMAKE_CURRENT_SOURCE_DIR}/allocator.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/binary.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/compiled.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/conv.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/copy.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/device.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/event.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/fft.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/indexing.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/matmul.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/scaled_dot_product_attention.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/metal.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/primitives.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/quantized.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/normalization.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/rope.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/scan.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/slicing.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/softmax.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/sort.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/reduce.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/ternary.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/unary.cpp
-)
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/allocator.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/binary.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/compiled.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/conv.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/copy.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/custom_kernel.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/distributed.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/device.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/event.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/fft.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/hadamard.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/indexing.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/matmul.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/scaled_dot_product_attention.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/metal.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/primitives.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/quantized.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/normalization.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/rope.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/scan.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/slicing.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/softmax.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/sort.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/reduce.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/ternary.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/unary.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/utils.cpp)
 
-if (NOT MLX_METAL_PATH)
+if(NOT MLX_METAL_PATH)
   set(MLX_METAL_PATH ${CMAKE_CURRENT_BINARY_DIR}/kernels/)
 endif()
 
 add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/kernels)
 
-target_compile_definitions(
-  mlx PRIVATE METAL_PATH="${MLX_METAL_PATH}/mlx.metallib")
+target_compile_definitions(mlx
+                           PRIVATE METAL_PATH="${MLX_METAL_PATH}/mlx.metallib")

mlx/backend/metal/allocator.cpp

@@ -241,9 +241,22 @@ void MetalAllocator::free(Buffer buffer) {
   }
 }
 
+size_t MetalAllocator::size(Buffer buffer) const {
+  return static_cast<MTL::Buffer*>(buffer.ptr())->length();
+}
+
 MetalAllocator& allocator() {
-  static MetalAllocator allocator_;
-  return allocator_;
+  // By creating the |allocator_| on heap, the destructor of MetalAllocator will
+  // not be called on exit and all the buffers will be leaked. This is necessary
+  // because releasing buffers can take more than 30sec when the program holds a
+  // lot of RAM (for example inferencing a LLM), and it would feel frozen to
+  // users when exiting.
+  // TODO(zcbenz): Consider using the `base::NoDestructor` class from Chromium
+  // when applying this pattern to more places, or when introducing sanitizers
+  // to MLX.
+  // https://source.chromium.org/chromium/chromium/src/+/main:base/no_destructor.h
+  static MetalAllocator* allocator_ = new MetalAllocator;
+  return *allocator_;
 }
 
 size_t set_cache_limit(size_t limit) {

mlx/backend/metal/allocator.h

@@ -56,6 +56,7 @@ class MetalAllocator : public allocator::Allocator {
  public:
   virtual Buffer malloc(size_t size, bool allow_swap = false) override;
   virtual void free(Buffer buffer) override;
+  virtual size_t size(Buffer buffer) const override;
   size_t get_active_memory() {
     return active_memory_;
   };

mlx/backend/metal/binary.cpp

@@ -6,14 +6,60 @@
 #include "mlx/backend/metal/utils.h"
 #include "mlx/primitives.h"
 
+#define BINARY_GPU(func)                                              \
+  void func::eval_gpu(const std::vector<array>& inputs, array& out) { \
+    binary_op_gpu(inputs, out, get_primitive_string(this));           \
+  }
+
+#define BINARY_GPU_MULTI(func)                                         \
+  void func::eval_gpu(                                                 \
+      const std::vector<array>& inputs, std::vector<array>& outputs) { \
+    binary_op_gpu(inputs, outputs, get_primitive_string(this));        \
+  }
+
 namespace mlx::core {
 
-constexpr int MAX_BINARY_SPECIALIZED_DIMS = 5;
+std::string get_kernel_name(
+    BinaryOpType bopt,
+    const std::string& op,
+    const array& a,
+    bool use_2d,
+    int ndim,
+    int work_per_thread) {
+  std::ostringstream kname;
+  switch (bopt) {
+    case BinaryOpType::ScalarScalar:
+      kname << "ss";
+      break;
+    case BinaryOpType::ScalarVector:
+      kname << (use_2d ? "sv2" : "sv");
+      break;
+    case BinaryOpType::VectorScalar:
+      kname << (use_2d ? "vs2" : "vs");
+      break;
+    case BinaryOpType::VectorVector:
+      kname << (use_2d ? "vv2" : "vv");
+      break;
+    case BinaryOpType::General:
+      kname << "g";
+      if (ndim <= 3) {
+        kname << ndim;
+      } else {
+        kname << "n";
+        if (work_per_thread > 1) {
+          kname << work_per_thread;
+        }
+      }
+      break;
+  }
+  kname << "_" << op << type_to_name(a);
+  return kname.str();
+}
 
 void binary_op_gpu_inplace(
     const std::vector<array>& inputs,
     std::vector<array>& outputs,
-    const std::string op,
+    const std::string& op,
     const Stream& s) {
   auto& a = inputs[0];
   auto& b = inputs[1];
@@ -25,78 +71,68 @@ void binary_op_gpu_inplace(
   }
 
   // Try to collapse contiguous dims
-  auto [shape, strides] = collapse_contiguous_dims(a, b, out);
-  auto& strides_a = strides[0];
-  auto& strides_b = strides[1];
-  auto& strides_out = strides[2];
-
-  std::string kernel_name;
-  {
-    std::ostringstream kname;
-    switch (bopt) {
-      case BinaryOpType::ScalarScalar:
-        kname << "ss";
-        break;
-      case BinaryOpType::ScalarVector:
-        kname << "sv";
-        break;
-      case BinaryOpType::VectorScalar:
-        kname << "vs";
-        break;
-      case BinaryOpType::VectorVector:
-        kname << "vv";
-        break;
-      case BinaryOpType::General:
-        kname << "g";
-        if (shape.size() <= MAX_BINARY_SPECIALIZED_DIMS) {
-          kname << shape.size();
-        } else {
-          kname << "n";
-        }
-        break;
+  auto maybe_collapse = [bopt, &a, &b, &out]() {
+    if (bopt == BinaryOpType::General) {
+      auto [shape, strides] = collapse_contiguous_dims(a, b, out);
+      return std::make_tuple(shape, strides[0], strides[1], strides[2]);
+    } else {
+      std::vector<size_t> e;
+      return std::make_tuple(std::vector<int>{}, e, e, e);
     }
-    kname << op << type_to_name(a);
-    kernel_name = kname.str();
-  }
+  };
+  auto [shape, strides_a, strides_b, strides_out] = maybe_collapse();
 
+  bool use_2d = out.data_size() > UINT32_MAX;
+  auto ndim = shape.size();
+  int work_per_thread =
+      (bopt == BinaryOpType::General && shape[ndim - 1] > 4) ? 4 : 1;
+  std::string kernel_name =
+      get_kernel_name(bopt, op, a, use_2d, shape.size(), work_per_thread);
   auto& d = metal::device(s.device);
 
-  auto kernel = get_binary_two_kernel(d, kernel_name, a, outputs[0]);
-
+  auto kernel = outputs.size() == 2
+      ? get_binary_two_kernel(d, kernel_name, a.dtype(), out.dtype(), op)
+      : get_binary_kernel(d, kernel_name, a.dtype(), out.dtype(), op);
   auto& compute_encoder = d.get_command_encoder(s.index);
   compute_encoder->setComputePipelineState(kernel);
 
   // - If a is donated it goes to the first output
   // - If b is donated it goes to the first output if a was not donated
-  //   otherwise it goes to the second output
+  //   otherwise it goes to the second output.
+  // - If there is only one output only one of a and b will be donated.
   bool donate_a = a.data_shared_ptr() == nullptr;
   bool donate_b = b.data_shared_ptr() == nullptr;
-  compute_encoder.set_input_array(donate_a ? outputs[0] : a, 0);
+  int arg_idx = 0;
+  compute_encoder.set_input_array(donate_a ? outputs[0] : a, arg_idx++);
   compute_encoder.set_input_array(
-      donate_b ? (donate_a ? outputs[1] : outputs[0]) : b, 1);
-  compute_encoder.set_output_array(outputs[0], 2);
-  compute_encoder.set_output_array(outputs[1], 3);
+      donate_b ? (donate_a ? outputs[1] : outputs[0]) : b, arg_idx++);
+  compute_encoder.set_output_array(outputs[0], arg_idx++);
+  if (outputs.size() == 2) {
+    compute_encoder.set_output_array(outputs[1], arg_idx++);
+  }
 
   if (bopt == BinaryOpType::General) {
-    auto ndim = shape.size();
-    if (ndim > 3) {
-      compute_encoder->setBytes(shape.data(), ndim * sizeof(int), 4);
-      compute_encoder->setBytes(strides_a.data(), ndim * sizeof(size_t), 5);
-      compute_encoder->setBytes(strides_b.data(), ndim * sizeof(size_t), 6);
-    } else {
-      // The shape is implicit in the grid for <= 3D
-      compute_encoder->setBytes(strides_a.data(), ndim * sizeof(size_t), 4);
-      compute_encoder->setBytes(strides_b.data(), ndim * sizeof(size_t), 5);
-    }
-
-    if (ndim > MAX_BINARY_SPECIALIZED_DIMS) {
-      compute_encoder->setBytes(&ndim, sizeof(int), 7);
-    }
-
     // Launch up to 3D grid of threads
     size_t dim0 = ndim > 0 ? shape[ndim - 1] : 1;
     size_t dim1 = ndim > 1 ? shape[ndim - 2] : 1;
     size_t rest = out.size() / (dim0 * dim1);
+
+    if (ndim > 3) {
+      compute_encoder->setBytes(shape.data(), ndim * sizeof(int), arg_idx++);
+      compute_encoder->setBytes(
+          strides_a.data(), ndim * sizeof(size_t), arg_idx++);
+      compute_encoder->setBytes(
+          strides_b.data(), ndim * sizeof(size_t), arg_idx++);
+      compute_encoder->setBytes(&ndim, sizeof(int), arg_idx++);
+      dim0 = (dim0 + work_per_thread - 1) / work_per_thread;
+    } else {
+      // The shape is implicit in the grid for <= 3D
+      compute_encoder->setBytes(
+          strides_a.data(), ndim * sizeof(size_t), arg_idx++);
+      compute_encoder->setBytes(
+          strides_b.data(), ndim * sizeof(size_t), arg_idx++);
+    }
+
     NS::UInteger thread_group_size = kernel->maxTotalThreadsPerThreadgroup();
     if (thread_group_size != 1024) {
       throw std::runtime_error("[Metal::binary] Must use 1024 sized block");
@@ -105,9 +141,10 @@ void binary_op_gpu_inplace(
     MTL::Size grid_dims = MTL::Size(dim0, dim1, rest);
     compute_encoder.dispatchThreads(grid_dims, group_dims);
   } else {
-    // Launch a 1D grid of threads
+    // Launch a 1D or 2D grid of threads
     size_t nthreads = out.data_size();
-    MTL::Size grid_dims = MTL::Size(nthreads, 1, 1);
+    MTL::Size grid_dims = use_2d ? get_2d_grid_dims(out.shape(), out.strides())
+                                 : MTL::Size(nthreads, 1, 1);
     NS::UInteger thread_group_size = kernel->maxTotalThreadsPerThreadgroup();
     if (thread_group_size > nthreads) {
       thread_group_size = nthreads;
@@ -120,7 +157,7 @@ void binary_op_gpu_inplace(
 void binary_op_gpu(
     const std::vector<array>& inputs,
     std::vector<array>& outputs,
-    const std::string op,
+    const std::string& op,
     const Stream& s) {
   assert(inputs.size() == 2);
   auto& a = inputs[0];
@@ -134,7 +171,7 @@ void binary_op_gpu(
 void binary_op_gpu(
     const std::vector<array>& inputs,
     std::vector<array>& outputs,
-    const std::string op) {
+    const std::string& op) {
   auto& s = outputs[0].primitive().stream();
   binary_op_gpu(inputs, outputs, op, s);
 }
@@ -142,106 +179,16 @@ void binary_op_gpu(
 void binary_op_gpu_inplace(
     const std::vector<array>& inputs,
     array& out,
-    const std::string op,
+    const std::string& op,
     const Stream& s) {
-  auto& a = inputs[0];
-  auto& b = inputs[1];
-  auto bopt = get_binary_op_type(a, b);
-  if (out.size() == 0) {
-    return;
-  }
-
-  // Try to collapse contiguous dims
-  auto [shape, strides] = collapse_contiguous_dims(a, b, out);
-  auto& strides_a = strides[0];
-  auto& strides_b = strides[1];
-  auto& strides_out = strides[2];
-
-  std::string kernel_name;
-  {
-    std::ostringstream kname;
-    switch (bopt) {
-      case BinaryOpType::ScalarScalar:
-        kname << "ss";
-        break;
-      case BinaryOpType::ScalarVector:
-        kname << "sv";
-        break;
-      case BinaryOpType::VectorScalar:
-        kname << "vs";
-        break;
-      case BinaryOpType::VectorVector:
-        kname << "vv";
-        break;
-      case BinaryOpType::General:
-        kname << "g";
-        if (shape.size() <= MAX_BINARY_SPECIALIZED_DIMS) {
-          kname << shape.size();
-        } else {
-          kname << "n";
-        }
-        break;
-    }
-    kname << op << type_to_name(a);
-    kernel_name = kname.str();
-  }
-
-  auto& d = metal::device(s.device);
-
-  auto kernel = get_binary_kernel(d, kernel_name, a, out);
-  auto& compute_encoder = d.get_command_encoder(s.index);
-  compute_encoder->setComputePipelineState(kernel);
-  bool donate_a = a.data_shared_ptr() == nullptr;
-  bool donate_b = b.data_shared_ptr() == nullptr;
-  compute_encoder.set_input_array(donate_a ? out : a, 0);
-  compute_encoder.set_input_array(donate_b ? out : b, 1);
-  compute_encoder.set_output_array(out, 2);
-
-  if (bopt == BinaryOpType::General) {
-    auto ndim = shape.size();
-    if (ndim > 3) {
-      compute_encoder->setBytes(shape.data(), ndim * sizeof(int), 3);
-      compute_encoder->setBytes(strides_a.data(), ndim * sizeof(size_t), 4);
-      compute_encoder->setBytes(strides_b.data(), ndim * sizeof(size_t), 5);
-    } else {
-      // The shape is implicit in the grid for <= 3D
-      compute_encoder->setBytes(strides_a.data(), ndim * sizeof(size_t), 3);
-      compute_encoder->setBytes(strides_b.data(), ndim * sizeof(size_t), 4);
-    }
-
-    if (ndim > MAX_BINARY_SPECIALIZED_DIMS) {
-      compute_encoder->setBytes(&ndim, sizeof(int), 6);
-    }
-
-    // Launch up to 3D grid of threads
-    size_t dim0 = ndim > 0 ? shape[ndim - 1] : 1;
-    size_t dim1 = ndim > 1 ? shape[ndim - 2] : 1;
-    size_t rest = out.size() / (dim0 * dim1);
-    NS::UInteger thread_group_size = kernel->maxTotalThreadsPerThreadgroup();
-    if (thread_group_size != 1024) {
-      throw std::runtime_error("[Metal::binary] Must use 1024 sized block");
-    }
-    auto group_dims = get_block_dims(dim0, dim1, rest);
-    MTL::Size grid_dims = MTL::Size(dim0, dim1, rest);
-    compute_encoder.dispatchThreads(grid_dims, group_dims);
-  } else {
-    // Launch a 1D grid of threads
-    size_t nthreads =
-        bopt == BinaryOpType::General ? out.size() : out.data_size();
-    MTL::Size grid_dims = MTL::Size(nthreads, 1, 1);
-    NS::UInteger thread_group_size = kernel->maxTotalThreadsPerThreadgroup();
-    if (thread_group_size > nthreads) {
-      thread_group_size = nthreads;
-    }
-    MTL::Size group_dims = MTL::Size(thread_group_size, 1, 1);
-    compute_encoder.dispatchThreads(grid_dims, group_dims);
-  }
+  std::vector<array> outputs = {out};
+  binary_op_gpu_inplace(inputs, outputs, op, s);
 }
 
 void binary_op_gpu(
     const std::vector<array>& inputs,
     array& out,
-    const std::string op,
+    const std::string& op,
     const Stream& s) {
   assert(inputs.size() == 2);
   auto& a = inputs[0];
@@ -254,107 +201,49 @@ void binary_op_gpu(
 void binary_op_gpu(
     const std::vector<array>& inputs,
     array& out,
-    const std::string op) {
+    const std::string& op) {
   auto& s = out.primitive().stream();
   binary_op_gpu(inputs, out, op, s);
 }
 
-void Add::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "add");
-}
-
-void ArcTan2::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "arctan2");
-}
+BINARY_GPU(Add)
+BINARY_GPU(ArcTan2)
+BINARY_GPU(Divide)
+BINARY_GPU_MULTI(DivMod)
+BINARY_GPU(Remainder)
+BINARY_GPU(Equal)
+BINARY_GPU(Greater)
+BINARY_GPU(GreaterEqual)
+BINARY_GPU(Less)
+BINARY_GPU(LessEqual)
+BINARY_GPU(LogicalAnd)
+BINARY_GPU(LogicalOr)
+BINARY_GPU(LogAddExp)
+BINARY_GPU(Maximum)
+BINARY_GPU(Minimum)
+BINARY_GPU(Multiply)
+BINARY_GPU(NotEqual)
+BINARY_GPU(Power)
+BINARY_GPU(Subtract)
 
 void BitwiseBinary::eval_gpu(const std::vector<array>& inputs, array& out) {
   switch (op_) {
     case BitwiseBinary::And:
-      binary_op_gpu(inputs, out, "bitwise_and");
+      binary_op_gpu(inputs, out, get_primitive_string(this));
       break;
     case BitwiseBinary::Or:
-      binary_op_gpu(inputs, out, "bitwise_or");
+      binary_op_gpu(inputs, out, get_primitive_string(this));
       break;
     case BitwiseBinary::Xor:
-      binary_op_gpu(inputs, out, "bitwise_xor");
+      binary_op_gpu(inputs, out, get_primitive_string(this));
       break;
     case BitwiseBinary::LeftShift:
-      binary_op_gpu(inputs, out, "left_shift");
+      binary_op_gpu(inputs, out, get_primitive_string(this));
       break;
     case BitwiseBinary::RightShift:
-      binary_op_gpu(inputs, out, "right_shift");
+      binary_op_gpu(inputs, out, get_primitive_string(this));
       break;
   }
 }
 
-void Divide::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "div");
-}
-
-void DivMod::eval_gpu(
-    const std::vector<array>& inputs,
-    std::vector<array>& outputs) {
-  binary_op_gpu(inputs, outputs, "divmod");
-}
-
-void Remainder::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "rem");
-}
-
-void Equal::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, equal_nan_ ? "naneq" : "eq");
-}
-
-void Greater::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "ge");
-}
-
-void GreaterEqual::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "geq");
-}
-
-void Less::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "le");
-}
-
-void LessEqual::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "leq");
-}
-
-void LogicalAnd::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "land");
-}
-
-void LogicalOr::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "lor");
-}
-
-void LogAddExp::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "lae");
-}
-
-void Maximum::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "max");
-}
-
-void Minimum::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "min");
-}
-
-void Multiply::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "mul");
-}
-
-void NotEqual::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "neq");
-}
-
-void Power::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "pow");
-}
-
-void Subtract::eval_gpu(const std::vector<array>& inputs, array& out) {
-  binary_op_gpu(inputs, out, "sub");
-}
-
 } // namespace mlx::core

mlx/backend/metal/binary.h

@@ -9,25 +9,25 @@ namespace mlx::core {
 void binary_op_gpu(
     const std::vector<array>& inputs,
     std::vector<array>& outputs,
-    const std::string op,
+    const std::string& op,
     const Stream& s);
 
 void binary_op_gpu(
     const std::vector<array>& inputs,
     array& out,
-    const std::string op,
+    const std::string& op,
     const Stream& s);
 
 void binary_op_gpu_inplace(
     const std::vector<array>& inputs,
     std::vector<array>& outputs,
-    const std::string op,
+    const std::string& op,
     const Stream& s);
 
 void binary_op_gpu_inplace(
     const std::vector<array>& inputs,
     array& out,
-    const std::string op,
+    const std::string& op,
     const Stream& s);
 
 } // namespace mlx::core

mlx/backend/metal/compiled.cpp

@@ -22,7 +22,8 @@ inline void build_kernel(
     const std::unordered_set<uintptr_t>& constant_ids,
     bool contiguous,
     int ndim,
-    bool dynamic_dims) {
+    bool dynamic_dims,
+    bool use_big_index = false) {
   // All outputs should have the exact same shape and will be row contiguous
   auto output_shape = outputs[0].shape();
   auto output_strides = outputs[0].strides();
@@ -84,9 +85,15 @@ inline void build_kernel(
 
   // The thread index in the whole grid
   os << "    uint3 pos [[thread_position_in_grid]]," << std::endl
-     << "    uint3 grid [[threads_per_grid]]) {" << std::endl
-     << "  uint index = pos.x + grid.x * (pos.y + grid.y * pos.z);"
-     << std::endl;
+     << "    uint3 grid [[threads_per_grid]]) {" << std::endl;
+  if (use_big_index) {
+    // This is only used for contiguous kernels which don't have
+    // a third grid dimension
+    os << "  size_t index = pos.x + grid.x * size_t(pos.y);";
+  } else {
+    os << "  uint index = pos.x + grid.x * (pos.y + grid.y * pos.z);";
+  }
+  os << std::endl;
 
   // Extract the indices per axis to individual uints if we have arrays that
   // are broadcasted or transposed
@@ -212,6 +219,17 @@ void Compiled::eval_gpu(
         /* contiguous = */ true,
         /* ndim = */ 0,
         /* dynamic_dims = */ false);
+    build_kernel(
+        kernel,
+        kernel_lib_ + "_contiguous_big",
+        inputs_,
+        outputs_,
+        tape_,
+        constant_ids_,
+        /* contiguous = */ true,
+        /* ndim = */ 0,
+        /* dynamic_dims = */ false,
+        /* use_big_index = */ true);
     for (int i = 1; i < 8; i++) {
       build_kernel(
           kernel,
@@ -285,7 +303,16 @@ void Compiled::eval_gpu(
       initial_strides.push_back(std::move(xstrides));
     }
     std::tie(shape, strides) =
-        collapse_contiguous_dims(output_shape, initial_strides);
+        collapse_contiguous_dims(output_shape, initial_strides, INT32_MAX);
+  }
+
+  bool use_2d = false;
+  if (contiguous) {
+    size_t max_size = 0;
+    for (auto& in : inputs) {
+      max_size = std::max(max_size, in.data_size());
+    }
+    use_2d = (max_size > UINT32_MAX);
   }
 
   // Get the kernel from the lib
@@ -298,6 +325,8 @@ void Compiled::eval_gpu(
     } else {
       kernel_name += std::to_string(shape.size());
     }
+  } else if (use_2d) {
+    kernel_name += "_big";
   }
   auto kernel = d.get_kernel(kernel_name, lib);
   auto& compute_encoder = d.get_command_encoder(s.index);
@@ -348,8 +377,10 @@ void Compiled::eval_gpu(
 
   // Launch the kernel
   if (contiguous) {
-    size_t nthreads = outputs[0].size();
-    MTL::Size grid_dims(nthreads, 1, 1);
+    size_t nthreads = outputs[0].data_size();
+    MTL::Size grid_dims = use_2d
+        ? get_2d_grid_dims(outputs[0].shape(), outputs[0].strides())
+        : MTL::Size(nthreads, 1, 1);
     MTL::Size group_dims(
         std::min(nthreads, kernel->maxTotalThreadsPerThreadgroup()), 1, 1);
     compute_encoder.dispatchThreads(grid_dims, group_dims);

mlx/backend/metal/conv.cpp

@@ -72,7 +72,7 @@ void explicit_gemm_conv_ND_gpu(
   wt_reshaped.copy_shared_buffer(wt, wt_restride, wt_flags, wt.data_size());
 
   // Perform gemm
-  std::vector<array> copies = {in_unfolded, wt_reshaped};
+  std::vector<array> copies = {in_unfolded};
   return steel_matmul(
       s,
       d,
@@ -155,22 +155,27 @@ void explicit_gemm_conv_group_ND_gpu(
   copy_gpu(wt_view, wt_transpose, CopyType::General, s);
 
   // Perform gemm
-  std::vector<array> copies = {in_unfolded, wt_view, wt_transpose};
-  return steel_matmul_conv_groups(
+  std::vector<array> copies = {in_unfolded, wt_transpose};
+  return steel_matmul_regular(
       s,
       d,
-      /*a = */ in_unfolded,
-      /*b = */ wt_transpose,
-      /*c = */ out,
-      /*M = */ implicit_M,
-      /*N = */ implicit_N,
-      /*K = */ implicit_K,
-      /*a_cols = */ implicit_K * groups,
-      /*b_cols = */ implicit_K,
-      /*out_cols = */ implicit_N * groups,
-      /*a_transposed = */ false,
-      /*b_transposed = */ true,
-      /* groups = */ groups,
+      /* a = */ in_unfolded,
+      /* b = */ wt_transpose,
+      /* c = */ out,
+      /* M = */ implicit_M,
+      /* N = */ implicit_N,
+      /* K = */ implicit_K,
+      /* batch_size_out = */ groups,
+      /* a_cols = */ implicit_K * groups,
+      /* b_cols = */ implicit_K,
+      /* out_cols = */ implicit_N * groups,
+      /* a_transposed = */ false,
+      /* b_transposed = */ true,
+      /* batch_shape = */ {1},
+      /* batch_strides = */ {0},
+      /* A_batch_strides = */ size_t(implicit_K),
+      /* B_batch_strides = */ size_t(implicit_N) * implicit_K,
+      /* matrix_stride_out = */ size_t(implicit_N),
       /*copies = */ copies);
 }
 
@@ -552,7 +557,7 @@ void winograd_conv_2D_gpu(
 
   // Fill with zeros
   array zero_arr = array(0, in.dtype());
-  copy_gpu(zero_arr, in_padded, CopyType::Scalar, s);
+  fill_gpu(zero_arr, in_padded, s);
   copies_w.push_back(zero_arr);
 
   // Pick input slice from padded
@@ -571,7 +576,6 @@ void winograd_conv_2D_gpu(
 
   copies_w.push_back(in_padded_slice);
   copies_w.push_back(in_padded);
-  copies_w.push_back(zero_arr);
 
   MLXConvParams<2> conv_params_updated{
       /* const int  N = */ in_padded.shape(0),
@@ -911,14 +915,16 @@ void Convolution::eval_gpu(const std::vector<array>& inputs, array& out) {
   // Throw error
   else {
     throw std::invalid_argument(
-        "[Convolution::eval_gpu] Only supports 1D or 2D convolutions.");
+        "[Convolution::eval_gpu] Only supports 1D, 2D or 3D convolutions.");
   }
 
   // Clear copies
-  if (copies.size() > 0) {
+  if (!copies.empty()) {
     auto command_buffer = d.get_command_buffer(s.index);
     command_buffer->addCompletedHandler(
-        [copies](MTL::CommandBuffer*) mutable { copies.clear(); });
+        [copies = std::move(copies)](MTL::CommandBuffer*) mutable {
+          copies.clear();
+        });
   }
 }
 

mlx/backend/metal/copy.cpp

@@ -10,7 +10,7 @@
 
 namespace mlx::core {
 
-constexpr int MAX_COPY_SPECIALIZED_DIMS = 5;
+constexpr int MAX_COPY_SPECIALIZED_DIMS = 3;
 
 void copy_gpu(const array& in, array& out, CopyType ctype, const Stream& s) {
   if (ctype == CopyType::Vector) {
@@ -59,21 +59,34 @@ void copy_gpu_inplace(
   }
 
   // Try to collapse contiguous dims
-  auto [shape, strides] = collapse_contiguous_dims(
-      data_shape, std::vector{strides_in_pre, strides_out_pre});
-  auto& strides_in_ = strides[0];
-  auto& strides_out_ = strides[1];
+  auto maybe_collapse =
+      [ctype, &data_shape, &strides_in_pre, &strides_out_pre]() {
+        if (ctype == CopyType::General || ctype == CopyType::GeneralGeneral) {
+          auto [shape, strides] = collapse_contiguous_dims(
+              data_shape,
+              std::vector{strides_in_pre, strides_out_pre},
+              /* size_cap = */ INT32_MAX);
+          return std::make_tuple(shape, strides[0], strides[1]);
+        } else {
+          std::vector<stride_t> e;
+          return std::make_tuple(std::vector<int>{}, e, e);
+        }
+      };
+  auto [shape, strides_in_, strides_out_] = maybe_collapse();
+  int ndim = shape.size();
 
+  bool use_2d = out.data_size() > UINT32_MAX;
   auto& d = metal::device(s.device);
+  int work_per_thread = 1;
   std::string kernel_name;
   {
     std::ostringstream kname;
     switch (ctype) {
       case CopyType::Scalar:
-        kname << "s";
+        kname << (use_2d ? "s2" : "s");
         break;
       case CopyType::Vector:
-        kname << "v";
+        kname << (use_2d ? "v2" : "v");
         break;
       case CopyType::General:
         kname << "g";
@@ -82,9 +95,13 @@ void copy_gpu_inplace(
         kname << "gg";
         break;
     }
-    if ((ctype == CopyType::General || ctype == CopyType::GeneralGeneral) &&
-        shape.size() <= MAX_COPY_SPECIALIZED_DIMS) {
-      kname << shape.size();
+    if (ctype == CopyType::General || ctype == CopyType::GeneralGeneral) {
+      if (shape.size() <= MAX_COPY_SPECIALIZED_DIMS) {
+        kname << shape.size();
+      } else if (shape[ndim - 1] >= 4) {
+        work_per_thread = 4;
+        kname << "n4";
+      }
     }
     kname << "_copy";
     kname << type_to_name(in) << type_to_name(out);
@@ -104,10 +121,8 @@ void copy_gpu_inplace(
   compute_encoder.set_output_array(out, 1, out_offset);
 
   if (ctype == CopyType::General || ctype == CopyType::GeneralGeneral) {
-    int ndim = shape.size();
     std::vector<int64_t> strides_in{strides_in_.begin(), strides_in_.end()};
     std::vector<int64_t> strides_out{strides_out_.begin(), strides_out_.end()};
-
     if (ndim > 3) {
       set_vector_bytes(compute_encoder, shape, ndim, 2);
     }
@@ -116,10 +131,6 @@ void copy_gpu_inplace(
       set_vector_bytes(compute_encoder, strides_out, ndim, 4);
     }
 
-    if (ndim > MAX_COPY_SPECIALIZED_DIMS) {
-      compute_encoder->setBytes(&ndim, sizeof(int), 5);
-    }
-
     int dim0 = ndim > 0 ? shape[ndim - 1] : 1;
     int dim1 = ndim > 1 ? shape[ndim - 2] : 1;
 
@@ -128,6 +139,11 @@ void copy_gpu_inplace(
       data_size *= s;
     int rest = data_size / (dim0 * dim1);
 
+    if (ndim > MAX_COPY_SPECIALIZED_DIMS) {
+      compute_encoder->setBytes(&ndim, sizeof(int), 5);
+      dim0 = (dim0 + work_per_thread - 1) / work_per_thread;
+    }
+
     // NB assuming thread_group_size is a power of 2 larger than 32 x 32
     NS::UInteger thread_group_size = kernel->maxTotalThreadsPerThreadgroup();
     if (thread_group_size != 1024) {
@@ -139,7 +155,8 @@ void copy_gpu_inplace(
     compute_encoder.dispatchThreads(grid_dims, group_dims);
   } else {
     size_t nthreads = out.data_size();
-    MTL::Size grid_dims = MTL::Size(nthreads, 1, 1);
+    MTL::Size grid_dims = use_2d ? get_2d_grid_dims(out.shape(), out.strides())
+                                 : MTL::Size(nthreads, 1, 1);
     NS::UInteger thread_group_size = kernel->maxTotalThreadsPerThreadgroup();
     if (thread_group_size > nthreads) {
       thread_group_size = nthreads;
@@ -154,6 +171,7 @@ void copy_gpu_inplace(
     array& out,
     CopyType ctype,
     const Stream& s) {
+  assert(in.shape() == out.shape());
   return copy_gpu_inplace(
       in, out, in.shape(), in.strides(), out.strides(), 0, 0, ctype, s);
 }
@@ -165,9 +183,37 @@ void copy_gpu_inplace(
     int64_t ioffset,
     CopyType ctype,
     const Stream& s) {
+  assert(in.shape() == out.shape());
   std::vector<int64_t> ostrides{out.strides().begin(), out.strides().end()};
   return copy_gpu_inplace(
       in, out, in.shape(), istride, ostrides, ioffset, 0, ctype, s);
 }
 
+void fill_gpu(const array& val, array& out, const Stream& s) {
+  if (out.size() == 0) {
+    return;
+  }
+  out.set_data(allocator::malloc_or_wait(out.nbytes()));
+  bool use_2d = out.data_size() > UINT32_MAX;
+  auto& d = metal::device(s.device);
+  std::string kernel_name = std::string(use_2d ? "s2" : "s") + "_copy" +
+      type_to_name(val) + type_to_name(out);
+  auto kernel = get_copy_kernel(d, kernel_name, val, out);
+  auto& compute_encoder = d.get_command_encoder(s.index);
+  compute_encoder->setComputePipelineState(kernel);
+
+  compute_encoder.set_input_array(val, 0);
+  compute_encoder.set_output_array(out, 1);
+
+  size_t nthreads = out.data_size();
+  MTL::Size grid_dims = use_2d ? get_2d_grid_dims(out.shape(), out.strides())
+                               : MTL::Size(nthreads, 1, 1);
+  NS::UInteger thread_group_size = kernel->maxTotalThreadsPerThreadgroup();
+  if (thread_group_size > nthreads) {
+    thread_group_size = nthreads;
+  }
+  MTL::Size group_dims = MTL::Size(thread_group_size, 1, 1);
+  compute_encoder.dispatchThreads(grid_dims, group_dims);
+}
+
 } // namespace mlx::core

mlx/backend/metal/copy.h

@@ -37,4 +37,7 @@ void copy_gpu_inplace(
     CopyType ctype,
     const Stream& s);
 
+// Fill the output with the scalar val
+void fill_gpu(const array& val, array& out, const Stream& s);
+
 } // namespace mlx::core

mlx/backend/metal/custom_kernel.cpp

@@ -0,0 +1,90 @@
+// Copyright © 2024 Apple Inc.
+
+#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/metal/jit/includes.h"
+#include "mlx/backend/metal/utils.h"
+#include "mlx/fast_primitives.h"
+
+namespace mlx::core::fast {
+
+void CustomKernel::eval_gpu(
+    const std::vector<array>& inputs,
+    std::vector<array>& outputs) {
+  auto& s = stream();
+
+  std::vector<array> copies;
+
+  for (auto& out : outputs) {
+    out.set_data(allocator::malloc_or_wait(out.nbytes()));
+    if (init_value_) {
+      copies.emplace_back(init_value_.value(), out.dtype());
+      fill_gpu(copies.back(), out, s);
+    }
+  }
+
+  auto check_input = [&copies, &s, this](const array& x) -> const array {
+    bool no_copy = x.flags().row_contiguous;
+    if (!ensure_row_contiguous_ || no_copy) {
+      return x;
+    } else {
+      copies.push_back(array(x.shape(), x.dtype(), nullptr, {}));
+      copy_gpu(x, copies.back(), CopyType::General, s);
+      return copies.back();
+    }
+  };
+  std::vector<const array> checked_inputs;
+  for (const array& in : inputs) {
+    checked_inputs.push_back(check_input(in));
+  }
+
+  auto& d = metal::device(s.device);
+  const auto& lib_name = name_;
+  auto lib = d.get_library(lib_name);
+  if (lib == nullptr) {
+    lib = d.get_library(lib_name, metal::utils() + source_);
+  }
+  auto kernel = d.get_kernel(name_, lib);
+  auto& compute_encoder = d.get_command_encoder(s.index);
+  compute_encoder->setComputePipelineState(kernel);
+  int index = 0;
+  for (int i = 0; i < checked_inputs.size(); i++) {
+    const array& in = checked_inputs[i];
+    auto& shape_info = shape_infos_[i];
+    compute_encoder.set_input_array(in, index);
+    index++;
+    if (in.ndim() > 0) {
+      int ndim = in.ndim();
+      if (shape_info.shape) {
+        set_vector_bytes(compute_encoder, in.shape(), ndim, index);
+        index++;
+      }
+      if (shape_info.strides) {
+        set_vector_bytes(compute_encoder, in.strides(), ndim, index);
+        index++;
+      }
+      if (shape_info.ndim) {
+        compute_encoder->setBytes(&ndim, sizeof(int), index);
+        index++;
+      }
+    }
+  }
+  for (auto& out : outputs) {
+    compute_encoder.set_output_array(out, index);
+    index++;
+  }
+
+  const auto [tx, ty, tz] = threadgroup_;
+  MTL::Size group_dims = MTL::Size(tx, ty, tz);
+  const auto [gx, gy, gz] = grid_;
+  MTL::Size grid_dims = MTL::Size(gx, gy, gz);
+  compute_encoder->dispatchThreads(grid_dims, group_dims);
+
+  if (!copies.empty()) {
+    d.get_command_buffer(s.index)->addCompletedHandler(
+        [copies = std::move(copies)](MTL::CommandBuffer*) mutable {
+          copies.clear();
+        });
+  }
+}
+
+} // namespace mlx::core::fast

mlx/backend/metal/device.cpp

@@ -1,8 +1,6 @@
 // Copyright © 2023-2024 Apple Inc.
 
-#include <dlfcn.h>
 #include <cstdlib>
-#include <filesystem>
 #include <sstream>
 
 #include <sys/sysctl.h>
@@ -14,11 +12,8 @@
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/metal.h"
 #include "mlx/backend/metal/metal_impl.h"
-#include "mlx/backend/metal/mps/gemm.h"
 #include "mlx/backend/metal/utils.h"
 
-namespace fs = std::filesystem;
-
 namespace mlx::core::metal {
 
 namespace {
@@ -30,7 +25,9 @@ constexpr int MAX_DISPATCHES_PER_ENCODER = 2;
 constexpr const char* default_mtllib_path = METAL_PATH;
 
 constexpr auto get_metal_version() {
-#if defined METAL_3_1
+#if (MLX_METAL_VERSION >= 320)
+  return MTL::LanguageVersion3_2;
+#elif (MLX_METAL_VERSION >= 310)
   return MTL::LanguageVersion3_1;
 #else
   return MTL::LanguageVersion3_0;
@@ -124,6 +121,49 @@ MTL::Library* load_library(
 
 } // namespace
 
+CommandEncoder::CommandEncoder(MTL::CommandBuffer* cbuf) : cbuf(cbuf) {
+  enc = cbuf->computeCommandEncoder(MTL::DispatchTypeConcurrent);
+  enc->retain();
+}
+
+CommandEncoder::~CommandEncoder() {
+  enc->endEncoding();
+  enc->release();
+}
+
+void CommandEncoder::set_input_array(
+    const array& a,
+    int idx,
+    int64_t offset /* = 0 */) {
+  auto r_buf = static_cast<MTL::Resource*>(const_cast<void*>(a.buffer().ptr()));
+  if (auto it = outputs.find(r_buf); it != outputs.end()) {
+    // Insert a barrier
+    enc->memoryBarrier(&r_buf, 1);
+
+    // Remove the output
+    outputs.erase(it);
+  }
+  auto a_buf = static_cast<const MTL::Buffer*>(a.buffer().ptr());
+  auto base_offset = a.data<char>() -
+      static_cast<char*>(const_cast<MTL::Buffer*>(a_buf)->contents());
+  base_offset += offset;
+  enc->setBuffer(a_buf, base_offset, idx);
+}
+
+void CommandEncoder::set_output_array(
+    array& a,
+    int idx,
+    int64_t offset /* = 0 */) {
+  // Add barriers before adding the output to the output set
+  set_input_array(a, idx, offset);
+  auto buf = static_cast<MTL::Resource*>(a.buffer().ptr());
+  if (concurrent) {
+    concurrent_outputs.insert(buf);
+  } else {
+    outputs.insert(buf);
+  }
+}
+
 void CommandEncoder::dispatchThreadgroups(
     MTL::Size grid_dims,
     MTL::Size group_dims) {
@@ -253,23 +293,13 @@ void Device::register_library(
   }
 }
 
-void Device::register_library(
-    const std::string& lib_name,
-    const std::function<std::string(const std::string&)>& lib_path_func) {
-  if (auto it = library_map_.find(lib_name); it == library_map_.end()) {
-    std::string new_lib_path = lib_path_func(lib_name);
-    auto new_lib = load_library(device_, lib_name, new_lib_path.c_str());
-    library_map_.insert({lib_name, new_lib});
-  }
-}
-
 MTL::Library* Device::get_library_cache_(const std::string& lib_name) {
   // Search for cached metal lib
   MTL::Library* mtl_lib;
   if (auto it = library_map_.find(lib_name); it != library_map_.end()) {
     mtl_lib = it->second;
   } else { // Look for metallib alongside library
-    register_library(lib_name);
+    register_library(lib_name, get_colocated_mtllib_path(lib_name));
     mtl_lib = library_map_[lib_name];
   }
 

mlx/backend/metal/device.h

@@ -3,15 +3,14 @@
 #pragma once
 
 #include <Metal/Metal.hpp>
+#include <dlfcn.h>
+#include <filesystem>
 #include <functional>
 #include <mutex>
 #include <string>
 #include <unordered_map>
 #include <unordered_set>
 
-#include <dlfcn.h>
-#include <filesystem>
-
 #include "mlx/array.h"
 #include "mlx/device.h"
 
@@ -19,6 +18,8 @@ namespace fs = std::filesystem;
 
 namespace mlx::core::metal {
 
+// Note, this function must be left inline in a header so that it is not
+// dynamically linked.
 inline std::string get_colocated_mtllib_path(const std::string& lib_name) {
   Dl_info info;
   std::string mtllib_path;
@@ -37,10 +38,7 @@ using MTLFCList =
     std::vector<std::tuple<const void*, MTL::DataType, NS::UInteger>>;
 
 struct CommandEncoder {
-  CommandEncoder(MTL::CommandBuffer* cbuf) : cbuf(cbuf) {
-    enc = cbuf->computeCommandEncoder(MTL::DispatchTypeConcurrent);
-    enc->retain();
-  };
+  CommandEncoder(MTL::CommandBuffer* cbuf);
   CommandEncoder(const CommandEncoder&) = delete;
   CommandEncoder& operator=(const CommandEncoder&) = delete;
 
@@ -63,34 +61,8 @@ struct CommandEncoder {
     return enc;
   }
 
-  void set_input_array(const array& a, int idx, int64_t offset = 0) {
-    auto r_buf =
-        static_cast<MTL::Resource*>(const_cast<void*>(a.buffer().ptr()));
-    if (auto it = outputs.find(r_buf); it != outputs.end()) {
-      // Insert a barrier
-      enc->memoryBarrier(&r_buf, 1);
-
-      // Remove the output
-      outputs.erase(it);
-    }
-    auto a_buf = static_cast<const MTL::Buffer*>(a.buffer().ptr());
-    auto base_offset = a.data<char>() -
-        static_cast<char*>(const_cast<MTL::Buffer*>(a_buf)->contents());
-    base_offset += offset;
-    enc->setBuffer(a_buf, base_offset, idx);
-  }
-
-  void set_output_array(array& a, int idx, int64_t offset = 0) {
-    // Add barriers before adding the output to the output set
-    set_input_array(a, idx, offset);
-    auto buf = static_cast<MTL::Resource*>(a.buffer().ptr());
-    if (concurrent) {
-      concurrent_outputs.insert(buf);
-    } else {
-      outputs.insert(buf);
-    }
-  }
-
+  void set_input_array(const array& a, int idx, int64_t offset = 0);
+  void set_output_array(array& a, int idx, int64_t offset = 0);
   void dispatchThreadgroups(MTL::Size grid_dims, MTL::Size group_dims);
   void dispatchThreads(MTL::Size grid_dims, MTL::Size group_dims);
 
@@ -98,10 +70,7 @@ struct CommandEncoder {
     return ConcurrentContext(*this);
   }
 
-  ~CommandEncoder() {
-    enc->endEncoding();
-    enc->release();
-  }
+  ~CommandEncoder();
 
  private:
   void maybe_split();
@@ -136,10 +105,14 @@ class Device {
   void register_library(
       const std::string& lib_name,
       const std::string& lib_path);
-  void register_library(
-      const std::string& lib_name,
-      const std::function<std::string(const std::string&)>& lib_path_func =
-          get_colocated_mtllib_path);
+
+  // Note, this should remain in the header so that it is not dynamically
+  // linked
+  void register_library(const std::string& lib_name) {
+    if (auto it = library_map_.find(lib_name); it == library_map_.end()) {
+      register_library(lib_name, get_colocated_mtllib_path(lib_name));
+    }
+  }
 
   MTL::Library* get_library(const std::string& name);
 

mlx/backend/metal/distributed.cpp

@@ -0,0 +1,142 @@
+// Copyright © 2024 Apple Inc.
+
+#include <cassert>
+
+#include "mlx/allocator.h"
+#include "mlx/backend/metal/device.h"
+#include "mlx/distributed/ops.h"
+#include "mlx/distributed/primitives.h"
+#include "mlx/scheduler.h"
+
+namespace mlx::core::distributed {
+
+void signal_and_wait(const array& in, const array& out, const Stream& s) {
+  auto& d = metal::device(s.device);
+  d.end_encoding(s.index);
+  auto command_buffer = d.get_command_buffer(s.index);
+  if (in.event().valid()) {
+    command_buffer->encodeSignalEvent(
+        static_cast<MTL::Event*>(in.event().raw_event().get()),
+        in.event().value());
+  }
+  command_buffer->encodeWait(
+      static_cast<MTL::Event*>(out.event().raw_event().get()),
+      out.event().value());
+}
+
+void AllReduce::eval_gpu(
+    const std::vector<array>& inputs,
+    std::vector<array>& outputs) {
+  assert(inputs.size() == 1);
+  assert(outputs.size() == 1);
+
+  auto& in = inputs[0];
+  auto& out = outputs[0];
+  if (in.is_donatable()) {
+    out.move_shared_buffer(in);
+  } else {
+    out.set_data(allocator::malloc_or_wait(out.nbytes()));
+  }
+
+  auto task = [in = in,
+               out = out,
+               reduce_type = reduce_type_,
+               group = group()]() mutable {
+    if (in.event().valid()) {
+      in.event().wait();
+    }
+    switch (reduce_type) {
+      case Sum:
+        distributed::detail::all_sum(
+            group, in.data_shared_ptr() == nullptr ? out : in, out);
+        break;
+      default:
+        throw std::runtime_error("Only all reduce sum is supported for now");
+    }
+    out.event().signal();
+  };
+  scheduler::enqueue(detail::communication_stream(), std::move(task));
+
+  signal_and_wait(in, out, stream());
+}
+
+void AllGather::eval_gpu(
+    const std::vector<array>& inputs,
+    std::vector<array>& outputs) {
+  assert(inputs.size() == 1);
+  assert(outputs.size() == 1);
+  auto& in = inputs[0];
+  auto& out = outputs[0];
+
+  out.set_data(allocator::malloc_or_wait(out.nbytes()));
+
+  auto task = [in = in, out = out, group = group()]() mutable {
+    if (in.event().valid()) {
+      in.event().wait();
+    }
+    distributed::detail::all_gather(group, in, out);
+    out.event().signal();
+  };
+  scheduler::enqueue(detail::communication_stream(), std::move(task));
+  signal_and_wait(in, out, stream());
+}
+
+void Send::eval_gpu(
+    const std::vector<array>& inputs,
+    std::vector<array>& outputs) {
+  assert(inputs.size() == 1);
+  assert(outputs.size() == 1);
+
+  auto& in = inputs[0];
+  auto& out = outputs[0];
+
+  // Schedule an async send on the comm stream
+  auto task = [in = in, out = out, group = group(), dst = dst_]() mutable {
+    if (in.event().valid()) {
+      in.event().wait();
+    }
+    distributed::detail::send(group, in, dst);
+    out.event().signal();
+  };
+  scheduler::enqueue(detail::communication_stream(), std::move(task));
+
+  // Encode a signal event for the input but not a wait since we don't need to
+  // wait on the output.
+  auto& s = stream();
+  auto& d = metal::device(s.device);
+  d.end_encoding(s.index);
+  auto command_buffer = d.get_command_buffer(s.index);
+  if (in.event().valid()) {
+    command_buffer->encodeSignalEvent(
+        static_cast<MTL::Event*>(in.event().raw_event().get()),
+        in.event().value());
+  }
+}
+
+void Recv::eval_gpu(
+    const std::vector<array>& inputs,
+    std::vector<array>& outputs) {
+  assert(inputs.size() == 0);
+  assert(outputs.size() == 1);
+
+  auto& out = outputs[0];
+
+  out.set_data(allocator::malloc_or_wait(out.nbytes()));
+
+  // Schedule an async recv on the comm stream
+  auto task = [out = out, group = group(), src = src_]() mutable {
+    distributed::detail::recv(group, out, src);
+    out.event().signal();
+  };
+  scheduler::enqueue(detail::communication_stream(), std::move(task));
+
+  // Encode a wait event as there is no input for the recv to encode a signal.
+  auto& s = stream();
+  auto& d = metal::device(s.device);
+  auto command_buffer = d.get_command_buffer(s.index);
+  command_buffer->encodeWait(
+      static_cast<MTL::Event*>(out.event().raw_event().get()),
+      out.event().value());
+}
+
+} // namespace mlx::core::distributed

mlx/backend/metal/event.cpp

@@ -27,4 +27,9 @@ void Event::signal() {
   static_cast<MTL::SharedEvent*>(raw_event().get())->setSignaledValue(value());
 }
 
+bool Event::is_signaled() const {
+  return static_cast<MTL::SharedEvent*>(raw_event().get())->signaledValue() >=
+      value();
+}
+
 } // namespace mlx::core

mlx/backend/metal/fft.cpp

@@ -1,4 +1,4 @@
-// Copyright © 2023 Apple Inc.
+// Copyright © 2024 Apple Inc.
 #include <cassert>
 #include <complex>
 #include <map>
@@ -12,8 +12,7 @@
 #include "mlx/backend/metal/slicing.h"
 #include "mlx/backend/metal/unary.h"
 #include "mlx/backend/metal/utils.h"
-#include "mlx/mlx.h"
-#include "mlx/primitives.h"
+#include "mlx/utils.h"
 
 namespace mlx::core {
 
@@ -391,16 +390,16 @@ void multi_upload_bluestein_fft(
     std::vector<int> rstrides(in.ndim(), 1);
     rstarts[axis] = in.shape(axis) - back_offset;
     rstrides[axis] = -1;
-    unary_op_gpu({in}, conj_temp, "conj", s);
+    unary_op_gpu({in}, conj_temp, "Conjugate", s);
     slice_gpu(in, slice_temp, rstarts, rstrides, s);
     concatenate_gpu({conj_temp, slice_temp}, temp, (int)axis, s);
   } else if (inverse) {
-    unary_op_gpu({in}, temp, "conj", s);
+    unary_op_gpu({in}, temp, "Conjugate", s);
   } else {
     temp.copy_shared_buffer(in);
   }
 
-  binary_op_gpu({temp, w_k_broadcast}, temp1, "mul", s);
+  binary_op_gpu({temp, w_k_broadcast}, temp1, "Multiply", s);
 
   std::vector<std::pair<int, int>> pads;
   auto padded_shape = out.shape();
@@ -419,7 +418,7 @@ void multi_upload_bluestein_fft(
       /*inplace=*/false,
       s);
 
-  binary_op_gpu_inplace({pad_temp1, w_q_broadcast}, pad_temp, "mul", s);
+  binary_op_gpu_inplace({pad_temp1, w_q_broadcast}, pad_temp, "Multiply", s);
 
   fft_op(
       pad_temp,
@@ -437,7 +436,7 @@ void multi_upload_bluestein_fft(
   starts[axis] = plan.bluestein_n - offset - n;
   slice_gpu(pad_temp1, temp, starts, strides, s);
 
-  binary_op_gpu_inplace({temp, w_k_broadcast}, temp1, "mul", s);
+  binary_op_gpu_inplace({temp, w_k_broadcast}, temp1, "Multiply", s);
 
   if (real && !inverse) {
     std::vector<int> rstarts(in.ndim(), 0);
@@ -451,11 +450,11 @@ void multi_upload_bluestein_fft(
     copies.push_back(inv_n);
 
     copy_gpu(temp1, temp_float, CopyType::General, s);
-    binary_op_gpu({temp_float, inv_n}, out, "mul", s);
+    binary_op_gpu({temp_float, inv_n}, out, "Multiply", s);
   } else if (inverse) {
     auto inv_n = array({1.0f / n}, {1}, complex64);
-    unary_op_gpu({temp1}, temp, "conj", s);
-    binary_op_gpu({temp, inv_n}, out, "mul", s);
+    unary_op_gpu({temp1}, temp, "Conjugate", s);
+    binary_op_gpu({temp, inv_n}, out, "Multiply", s);
     copies.push_back(inv_n);
   } else {
     out.copy_shared_buffer(temp1);
@@ -547,8 +546,8 @@ void fft_op(
       auto [data_size, is_row_contiguous, is_col_contiguous] =
           check_contiguity(x.shape(), strides);
 
-      flags.col_contiguous = is_row_contiguous;
-      flags.row_contiguous = is_col_contiguous;
+      flags.col_contiguous = is_col_contiguous;
+      flags.row_contiguous = is_row_contiguous;
       flags.contiguous = data_size == x_copy.size();
 
       x_copy.set_data(
@@ -577,7 +576,9 @@ void fft_op(
   if (plan.four_step) {
     four_step_fft(in, out, axis, inverse, real, plan, copies, s);
     d.get_command_buffer(s.index)->addCompletedHandler(
-        [copies](MTL::CommandBuffer*) mutable { copies.clear(); });
+        [copies = std::move(copies)](MTL::CommandBuffer*) mutable {
+          copies.clear();
+        });
     return;
   }
 
@@ -661,34 +662,45 @@ void fft_op(
     std::ostringstream kname;
     std::string inv_string = inverse ? "true" : "false";
     std::string real_string = real ? "true" : "false";
+    std::string func_name;
     if (plan.bluestein_n > 0) {
       kname << "bluestein_fft_mem_" << threadgroup_mem_size << "_"
             << in_type_str << "_" << out_type_str;
+      func_name = "bluestein_fft";
     } else if (plan.rader_n > 1) {
       kname << "rader_fft_mem_" << threadgroup_mem_size << "_" << in_type_str
             << "_" << out_type_str;
+      func_name = "rader_fft";
     } else if (four_step_params.required) {
       step = four_step_params.first_step ? 0 : 1;
       kname << "four_step_mem_" << threadgroup_mem_size << "_" << in_type_str
             << "_" << out_type_str << "_" << step << "_" << real_string;
+      func_name = "four_step_fft";
     } else {
       kname << "fft_mem_" << threadgroup_mem_size << "_" << in_type_str << "_"
             << out_type_str;
+      func_name = "fft";
     }
     std::string base_name = kname.str();
     // We use a specialized kernel for each FFT size
     kname << "_n" << fft_size << "_inv_" << inverse;
     std::string hash_name = kname.str();
-    auto kernel = get_fft_kernel(
-        d,
-        base_name,
-        hash_name,
-        threadgroup_mem_size,
-        in_type_str,
-        out_type_str,
-        step,
-        real,
-        func_consts);
+    auto template_def = func_name == "four_step_fft" ? get_template_definition(
+                                                           base_name,
+                                                           func_name,
+                                                           threadgroup_mem_size,
+                                                           in_type_str,
+                                                           out_type_str,
+                                                           step,
+                                                           real)
+                                                     : get_template_definition(
+                                                           base_name,
+                                                           func_name,
+                                                           threadgroup_mem_size,
+                                                           in_type_str,
+                                                           out_type_str);
+    auto kernel =
+        get_fft_kernel(d, base_name, hash_name, func_consts, template_def);
 
     compute_encoder->setComputePipelineState(kernel);
     compute_encoder.set_input_array(in_contiguous, 0);
@@ -731,8 +743,13 @@ void fft_op(
         MTL::Size(batch_size, threadgroup_batch_size, threads_per_fft);
     compute_encoder->dispatchThreads(grid_dims, group_dims);
   }
-  d.get_command_buffer(s.index)->addCompletedHandler(
-      [copies](MTL::CommandBuffer*) mutable { copies.clear(); });
+
+  if (!copies.empty()) {
+    d.get_command_buffer(s.index)->addCompletedHandler(
+        [copies = std::move(copies)](MTL::CommandBuffer*) mutable {
+          copies.clear();
+        });
+  }
 }
 
 void fft_op(
@@ -774,10 +791,9 @@ void nd_fft_op(
     fft_op(in_arr, out_arr, axis, inverse, step_real, inplace, s);
   }
 
-  std::vector<array> copies = {temp1, temp2};
   auto& d = metal::device(s.device);
   d.get_command_buffer(s.index)->addCompletedHandler(
-      [copies](MTL::CommandBuffer*) mutable { copies.clear(); });
+      [temp_arrs](MTL::CommandBuffer*) mutable { temp_arrs.clear(); });
 }
 
 void FFT::eval_gpu(const std::vector<array>& inputs, array& out) {

mlx/backend/metal/hadamard.cpp

@@ -0,0 +1,207 @@
+// Copyright © 2024 Apple Inc.
+
+#include <map>
+
+#include "mlx/backend/common/compiled.h"
+#include "mlx/backend/common/hadamard.h"
+#include "mlx/backend/common/utils.h"
+#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/metal/device.h"
+#include "mlx/backend/metal/jit/includes.h"
+#include "mlx/backend/metal/kernels.h"
+#include "mlx/backend/metal/utils.h"
+#include "mlx/primitives.h"
+
+namespace mlx::core {
+
+constexpr int MAX_HADAMARD_THREADS_PER_GROUP = 256;
+constexpr int MAX_HADAMARD_BYTES = 32768; // 32KB
+
+std::string gen_hadamard_codelet(int m) {
+  // Generate a O(m^2) hadamard codelet for a given M
+  // using the hadamard matrices above
+  //
+  // e.g. m = 2
+  // METAL_FUNC void hadamard_m(thread float *x) {
+  //   float tmp[2];
+  //   tmp[0] = + x[0] + x[1];
+  //   tmp[1] = + x[0] - x[1];
+  //   for (int i = 0; i < 2; i++) { x[i] = tmp[i]; }
+  // }
+  //
+  auto h_matrices = hadamard_matrices();
+  auto& matrix = h_matrices[m];
+
+  std::ostringstream source;
+  source << "METAL_FUNC void hadamard_radix_m(thread float *x) {" << std::endl;
+  if (m == 1) {
+    source << "}" << std::endl;
+    return source.str();
+  }
+  source << "  float tmp[" << m << "];" << std::endl;
+  auto start = 1;
+  auto end = matrix.find('\n', start);
+
+  int index = 0;
+  while (end != std::string_view::npos) {
+    source << "  tmp[" << index << "] = ";
+    auto row = matrix.substr(start, end - start);
+    for (int i = 0; i < row.length(); i++) {
+      source << " " << row[i] << " x[" << i << "]";
+    }
+    source << ";" << std::endl;
+    start = end + 1;
+    end = matrix.find('\n', start);
+    index++;
+  }
+  source << "  for (int i = 0; i < " << m << "; i++) { x[i] = tmp[i]; }"
+         << std::endl;
+  source << "}" << std::endl;
+  return source.str();
+}
+
+void launch_hadamard(
+    const array& in,
+    array& out,
+    int batch_size,
+    int threads_per,
+    const std::string kernel_name,
+    float scale,
+    const Stream& s) {
+  auto& d = metal::device(s.device);
+
+  const auto& lib_name = kernel_name.substr(1);
+  auto lib = d.get_library(lib_name);
+  auto kernel = d.get_kernel(kernel_name, lib);
+  assert(threads_per <= kernel->maxTotalThreadsPerThreadgroup());
+
+  auto& compute_encoder = d.get_command_encoder(s.index);
+  compute_encoder->setComputePipelineState(kernel);
+  compute_encoder.set_input_array(in, 0);
+  compute_encoder.set_output_array(out, 1);
+  compute_encoder->setBytes(&scale, sizeof(float), 2);
+
+  MTL::Size group_dims = MTL::Size(1, threads_per, 1);
+  MTL::Size grid_dims = MTL::Size(batch_size, threads_per, 1);
+  compute_encoder->dispatchThreads(grid_dims, group_dims);
+}
+
+void Hadamard::eval_gpu(const std::vector<array>& inputs, array& out) {
+  auto& s = stream();
+
+  auto& in = inputs[0];
+
+  std::vector<array> copies;
+  // Only support the last axis for now
+  int axis = in.ndim() - 1;
+  auto check_input = [&copies, &s](const array& x) {
+    // TODO(alexbarron) pass strides to kernel to relax this constraint
+    bool no_copy = x.flags().row_contiguous;
+    if (no_copy) {
+      return x;
+    } else {
+      copies.push_back(array(x.shape(), x.dtype(), nullptr, {}));
+      copy_gpu(x, copies.back(), CopyType::General, s);
+      return copies.back();
+    }
+  };
+  const array& in_contiguous = check_input(in);
+
+  if (in_contiguous.is_donatable()) {
+    out.move_shared_buffer(in_contiguous);
+  } else {
+    out.set_data(allocator::malloc_or_wait(out.nbytes()));
+  }
+
+  auto [n, m] = decompose_hadamard(in.shape(axis));
+
+  if (n * (int)size_of(in.dtype()) > MAX_HADAMARD_BYTES) {
+    throw std::invalid_argument(
+        "[hadamard] For n = m*2^k, 2^k > 8192 for FP32 or 2^k > 16384 for FP16/BF16 NYI");
+  }
+
+  int max_radix = std::min(n, 16);
+  // Use read_width 2 for m = 28 to avoid register spilling
+  int read_width = (n == 2 || m == 28) ? 2 : 4;
+
+  std::ostringstream kname;
+  kname << "hadamard_" << n * m << "_" << type_to_name(out);
+  auto kernel_name = kname.str();
+  auto& d = metal::device(s.device);
+  const auto& lib_name = kernel_name;
+  auto lib = d.get_library(lib_name);
+  if (lib == nullptr) {
+    std::ostringstream kernel_source;
+    auto codelet = gen_hadamard_codelet(m);
+    kernel_source << metal::utils() << codelet << metal::hadamard();
+    kernel_source << get_template_definition(
+        "n" + kernel_name,
+        "hadamard_n",
+        get_type_string(in.dtype()),
+        n,
+        max_radix,
+        read_width);
+    kernel_source << get_template_definition(
+        "m" + kernel_name,
+        "hadamard_m",
+        get_type_string(in.dtype()),
+        n,
+        m,
+        read_width);
+    lib = d.get_library(lib_name, kernel_source.str());
+  }
+
+  int batch_size = in.size() / n;
+  int threads_per = n / max_radix;
+
+  if (m > 1) {
+    // When m is greater than 1, we decompose the
+    // computation into two uploads to the GPU:
+    //
+    // e.g. len(x) = 12*4 = 48, m = 12, n = 4
+    //
+    // y = h48 @ x
+    //
+    // Upload 1:
+    // tmp = a.reshape(12, 4) @ h4
+    //
+    // Upload 2:
+    // y = h12 @ tmp
+    array temp(in.shape(), in.dtype(), nullptr, {});
+    temp.set_data(allocator::malloc_or_wait(temp.nbytes()));
+    copies.push_back(temp);
+
+    launch_hadamard(
+        in_contiguous,
+        temp,
+        batch_size,
+        threads_per,
+        "n" + kernel_name,
+        1.0,
+        s);
+
+    // Metal sometimes reports 256 max threads per group for hadamard_m kernel
+    threads_per = std::min(n / read_width, MAX_HADAMARD_THREADS_PER_GROUP);
+    batch_size = in.size() / m / read_width / threads_per;
+    launch_hadamard(
+        temp, out, batch_size, threads_per, "m" + kernel_name, scale_, s);
+  } else {
+    launch_hadamard(
+        in_contiguous,
+        out,
+        batch_size,
+        threads_per,
+        "n" + kernel_name,
+        scale_,
+        s);
+  }
+
+  if (!copies.empty()) {
+    d.get_command_buffer(s.index)->addCompletedHandler(
+        [copies = std::move(copies)](MTL::CommandBuffer*) mutable {
+          copies.clear();
+        });
+  }
+}
+
+} // namespace mlx::core

mlx/backend/metal/indexing.cpp

@@ -95,11 +95,21 @@ void Gather::eval_gpu(const std::vector<array>& inputs, array& out) {
     slice_size *= s;
   }
 
-  // Launch 2D grid of threads: indices x slice
-  size_t dim0 = out.size() / slice_size;
-  size_t dim1 = slice_size;
-  auto group_dims = get_block_dims(dim0, dim1, 1);
-  MTL::Size grid_dims = MTL::Size(dim0, dim1, 1);
+  // Launch 3D grid of threads
+  // First two dimensions for the indices, the last one for the slice
+  size_t dim0 = 1;
+  size_t dim1 = 1;
+  if (nidx) {
+    if (inputs[1].ndim() >= 1) {
+      dim0 = inputs[1].shape(0);
+    }
+    if (inputs[1].ndim() >= 2) {
+      dim1 = inputs[1].size() / dim0;
+    }
+  }
+  size_t dim2 = slice_size;
+  auto group_dims = get_block_dims(dim0, dim1, dim2);
+  MTL::Size grid_dims = MTL::Size(dim0, dim1, dim2);
 
   // Collect all idx shapes and strides into one place
   std::vector<int> idx_shapes;
@@ -293,7 +303,18 @@ void Scatter::eval_gpu(const std::vector<array>& inputs, array& out) {
         out.shape().data(), out.shape().size() * sizeof(int), 3);
     compute_encoder->setBytes(
         out.strides().data(), out.strides().size() * sizeof(size_t), 4);
-    compute_encoder->setBytes(&upd_size, sizeof(size_t), 5);
+
+    size_t out_ndim = out.ndim();
+    compute_encoder->setBytes(&out_ndim, sizeof(out_ndim), 5);
+    if (upd_ndim <= 1) {
+      // Placeholder so Metal doesn't compalain
+      int shape_ = 0;
+      compute_encoder->setBytes(&shape_, sizeof(int), 6);
+    } else {
+      compute_encoder->setBytes(upd.shape().data(), upd_ndim * sizeof(int), 6);
+    }
+    compute_encoder->setBytes(&upd_ndim, sizeof(size_t), 7);
+    compute_encoder->setBytes(&upd_size, sizeof(size_t), 8);
 
     // Set index buffers
     for (int i = 0; i < nidx; ++i) {