Move common gpu primitives to backend/gpu (#2145)

mlx/CMakeLists.txt

@@ -47,6 +47,7 @@ add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/distributed)
 add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/io)
 
 if(MLX_BUILD_METAL)
+  add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backend/gpu)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/backend/metal)
 else()
   target_sources(mlx

mlx/backend/gpu/CMakeLists.txt

@@ -0,0 +1,5 @@
+target_sources(
+  mlx
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/copy.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/primitives.cpp
+          ${CMAKE_CURRENT_SOURCE_DIR}/slicing.cpp)

mlx/backend/gpu/copy.cpp

@@ -0,0 +1,49 @@
+// Copyright © 2023-2024 Apple Inc.
+
+#include "mlx/backend/gpu/copy.h"
+#include "mlx/primitives.h"
+
+#include <cassert>
+
+namespace mlx::core {
+
+void copy_gpu(const array& in, array& out, CopyType ctype, const Stream& s) {
+  bool donated = set_copy_output_data(in, out, ctype);
+  if (donated && in.dtype() == out.dtype()) {
+    // If the output has the same type as the input then there is nothing to
+    // copy, just use the buffer.
+    return;
+  }
+  if (ctype == CopyType::GeneralGeneral) {
+    ctype = CopyType::General;
+  }
+  copy_gpu_inplace(in, out, ctype, s);
+}
+
+void copy_gpu(const array& in, array& out, CopyType ctype) {
+  copy_gpu(in, out, ctype, out.primitive().stream());
+}
+
+void copy_gpu_inplace(
+    const array& in,
+    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);
+}
+
+void copy_gpu_inplace(
+    const array& in,
+    array& out,
+    const Strides& i_strides,
+    int64_t i_offset,
+    CopyType ctype,
+    const Stream& s) {
+  assert(in.shape() == out.shape());
+  return copy_gpu_inplace(
+      in, out, in.shape(), i_strides, out.strides(), i_offset, 0, ctype, s);
+}
+
+} // namespace mlx::core

mlx/backend/gpu/copy.h

@@ -5,6 +5,8 @@
 #include "mlx/backend/common/copy.h"
 #include "mlx/stream.h"
 
+#include <optional>
+
 namespace mlx::core {
 
 // Generic copy inplace

mlx/backend/gpu/primitives.cpp

@@ -0,0 +1,217 @@
+// Copyright © 2025 Apple Inc.
+
+#include "mlx/primitives.h"
+#include "mlx/backend/common/utils.h"
+#include "mlx/backend/gpu/copy.h"
+#include "mlx/backend/gpu/slicing.h"
+
+#include <cassert>
+
+#define MLX_PROFILER_RANGE(message)
+
+namespace mlx::core {
+
+namespace {
+
+void reshape(const array& in, array& out, Stream s) {
+  auto [copy_necessary, out_strides] = prepare_reshape(in, out);
+  if (copy_necessary) {
+    out.set_data(allocator::malloc(out.nbytes()));
+    copy_gpu_inplace(
+        in,
+        out,
+        in.shape(),
+        in.strides(),
+        make_contiguous_strides(in.shape()),
+        0,
+        0,
+        CopyType::General,
+        s);
+  } else {
+    shared_buffer_reshape(in, out_strides, out);
+  }
+}
+
+} // namespace
+
+void AsStrided::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("AsStrided::eval_gpu");
+  eval(inputs, out);
+}
+
+void AsType::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("AsType::eval_gpu");
+  CopyType ctype =
+      inputs[0].flags().contiguous ? CopyType::Vector : CopyType::General;
+  copy_gpu(inputs[0], out, ctype);
+}
+
+void Broadcast::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("Broadcast::eval_gpu");
+  eval(inputs, out);
+}
+
+void BroadcastAxes::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("BroadcastAxes::eval_gpu");
+  eval(inputs, out);
+}
+
+void Concatenate::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("Concatenate::eval_gpu");
+  concatenate_gpu(inputs, out, axis_, stream());
+}
+
+void Contiguous::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("Contiguous::eval_gpu");
+  assert(inputs.size() == 1);
+  auto& in = inputs[0];
+  constexpr size_t extra_bytes = 16384;
+  if (in.buffer_size() <= out.nbytes() + extra_bytes &&
+      (in.flags().row_contiguous ||
+       (allow_col_major_ && in.flags().col_contiguous))) {
+    out.copy_shared_buffer(in);
+  } else {
+    copy_gpu(in, out, CopyType::General);
+  }
+}
+
+void Copy::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("Copy::eval_gpu");
+  eval(inputs, out);
+}
+
+void CustomTransforms::eval_gpu(
+    const std::vector<array>& inputs,
+    std::vector<array>& outputs) {
+  MLX_PROFILER_RANGE("CustomTransforms::eval_gpu");
+  eval(inputs, outputs);
+}
+
+void Depends::eval_gpu(
+    const std::vector<array>& inputs,
+    std::vector<array>& outputs) {
+  MLX_PROFILER_RANGE("Depends::eval_gpu");
+  eval(inputs, outputs);
+}
+
+void ExpandDims::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("ExpandDims::eval_gpu");
+  eval(inputs, out);
+}
+
+void Full::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("Full::eval_gpu");
+  auto in = inputs[0];
+  CopyType ctype;
+  if (in.data_size() == 1) {
+    ctype = CopyType::Scalar;
+  } else if (in.flags().contiguous) {
+    ctype = CopyType::Vector;
+  } else {
+    ctype = CopyType::General;
+  }
+  copy_gpu(in, out, ctype);
+}
+
+void Flatten::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("Flatten::eval_gpu");
+  reshape(inputs[0], out, stream());
+}
+
+void NumberOfElements::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("NumberOfElements::eval_gpu");
+  eval(inputs, out);
+}
+
+void Pad::eval_gpu(const std::vector<array>& inputs, array& out) {
+  // Inputs must be base input array and scalar val array
+  assert(inputs.size() == 2);
+  auto& in = inputs[0];
+  auto& val = inputs[1];
+
+  // Padding value must be a scalar
+  assert(val.size() == 1);
+
+  // Padding value, input and output must be of the same type
+  assert(val.dtype() == in.dtype() && in.dtype() == out.dtype());
+
+  pad_gpu(in, val, out, axes_, low_pad_size_, stream());
+}
+
+void Reshape::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("Reshape::eval_gpu");
+  reshape(inputs[0], out, stream());
+}
+
+void Split::eval_gpu(
+    const std::vector<array>& inputs,
+    std::vector<array>& outputs) {
+  MLX_PROFILER_RANGE("Split::eval_gpu");
+  eval(inputs, outputs);
+}
+
+void Slice::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("Slice::eval_gpu");
+  assert(inputs.size() == 1);
+  if (out.size() == 0) {
+    out.set_data(nullptr);
+    return;
+  }
+
+  auto& in = inputs[0];
+  slice_gpu(in, out, start_indices_, strides_, stream());
+}
+
+void Squeeze::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("Squeeze::eval_gpu");
+  eval(inputs, out);
+}
+
+void StopGradient::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("StopGradient::eval_gpu");
+  eval(inputs, out);
+}
+
+void Transpose::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("Transpose::eval_gpu");
+  eval(inputs, out);
+}
+
+void Unflatten::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("Unflatten::eval_gpu");
+  reshape(inputs[0], out, stream());
+}
+
+void View::eval_gpu(const std::vector<array>& inputs, array& out) {
+  MLX_PROFILER_RANGE("View::eval_gpu");
+  auto& in = inputs[0];
+  auto ibytes = size_of(in.dtype());
+  auto obytes = size_of(out.dtype());
+  // Conditions for buffer copying (disjunction):
+  // - type size is the same
+  // - type size is smaller and the last axis is contiguous
+  // - the entire array is row contiguous
+  if (ibytes == obytes || (obytes < ibytes && in.strides().back() == 1) ||
+      in.flags().row_contiguous) {
+    auto strides = in.strides();
+    for (int i = 0; i < static_cast<int>(strides.size()) - 1; ++i) {
+      strides[i] *= ibytes;
+      strides[i] /= obytes;
+    }
+    out.copy_shared_buffer(
+        in, strides, in.flags(), in.data_size() * ibytes / obytes);
+  } else {
+    auto tmp = array(in.shape(), in.dtype(), nullptr, {});
+    tmp.set_data(allocator::malloc(tmp.nbytes()));
+    copy_gpu_inplace(in, tmp, CopyType::General, stream());
+
+    auto flags = out.flags();
+    flags.contiguous = true;
+    flags.row_contiguous = true;
+    auto max_dim = std::max_element(out.shape().begin(), out.shape().end());
+    flags.col_contiguous = out.size() <= 1 || out.size() == *max_dim;
+    out.copy_shared_buffer(tmp, out.strides(), flags, out.size());
+  }
+}
+
+} // namespace mlx::core

mlx/backend/gpu/slicing.cpp

@@ -0,0 +1,44 @@
+// Copyright © 2025 Apple Inc.
+
+#include "mlx/backend/common/slicing.h"
+#include "mlx/backend/gpu/copy.h"
+#include "mlx/backend/gpu/slicing.h"
+
+namespace mlx::core {
+
+void slice_gpu(
+    const array& in,
+    array& out,
+    const Shape& start_indices,
+    const Shape& strides,
+    const Stream& s) {
+  slice(in, out, start_indices, strides);
+}
+
+void pad_gpu(
+    const array& in,
+    const array& val,
+    array& out,
+    const std::vector<int>& axes,
+    const Shape& low_pad_size,
+    const Stream& s) {
+  // Fill output with val
+  fill_gpu(val, out, s);
+
+  // Find offset for start of input values
+  size_t data_offset = 0;
+  for (int i = 0; i < axes.size(); i++) {
+    auto ax = axes[i] < 0 ? out.ndim() + axes[i] : axes[i];
+    data_offset += out.strides()[ax] * low_pad_size[i];
+  }
+
+  // Extract slice from output where input will be pasted
+  array out_slice(in.shape(), out.dtype(), nullptr, {});
+  out_slice.copy_shared_buffer(
+      out, out.strides(), out.flags(), out_slice.size(), data_offset);
+
+  // Copy input values into the slice
+  copy_gpu_inplace(in, out_slice, CopyType::GeneralGeneral, s);
+}
+
+} // namespace mlx::core

mlx/backend/metal/conv.cpp

@@ -5,7 +5,7 @@
 #include <numeric>
 #include <sstream>
 
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/kernels.h"
 #include "mlx/backend/metal/kernels/defines.h"

mlx/backend/metal/copy.cpp

@@ -1,35 +1,15 @@
 // Copyright © 2023-2024 Apple Inc.
 
-#include <sstream>
+#include "mlx/backend/gpu/copy.h"
-
 #include "mlx/backend/common/utils.h"
-#include "mlx/backend/metal/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/kernels.h"
 #include "mlx/backend/metal/utils.h"
-#include "mlx/primitives.h"
 
 namespace mlx::core {
 
 constexpr int MAX_COPY_SPECIALIZED_DIMS = 3;
 
-void copy_gpu(const array& in, array& out, CopyType ctype, const Stream& s) {
-  bool donated = set_copy_output_data(in, out, ctype);
-  if (donated && in.dtype() == out.dtype()) {
-    // If the output has the same type as the input then there is nothing to
-    // copy, just use the buffer.
-    return;
-  }
-  if (ctype == CopyType::GeneralGeneral) {
-    ctype = CopyType::General;
-  }
-  copy_gpu_inplace(in, out, ctype, s);
-}
-
-void copy_gpu(const array& in, array& out, CopyType ctype) {
-  copy_gpu(in, out, ctype, out.primitive().stream());
-}
-
 void copy_gpu_inplace(
     const array& in,
     array& out,
@@ -184,28 +164,6 @@ void copy_gpu_inplace(
   }
 }
 
-void copy_gpu_inplace(
-    const array& in,
-    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);
-}
-
-void copy_gpu_inplace(
-    const array& in,
-    array& out,
-    const Strides& i_strides,
-    int64_t i_offset,
-    CopyType ctype,
-    const Stream& s) {
-  assert(in.shape() == out.shape());
-  return copy_gpu_inplace(
-      in, out, in.shape(), i_strides, out.strides(), i_offset, 0, ctype, s);
-}
-
 void fill_gpu(const array& val, array& out, const Stream& s) {
   if (out.size() == 0) {
     return;

mlx/backend/metal/custom_kernel.cpp

@@ -1,6 +1,6 @@
 // Copyright © 2024 Apple Inc.
 
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/jit/includes.h"
 #include "mlx/backend/metal/utils.h"
 #include "mlx/fast_primitives.h"

mlx/backend/metal/distributed.cpp

@@ -4,7 +4,7 @@
 
 #include "mlx/allocator.h"
 #include "mlx/backend/common/utils.h"
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/utils.h"
 #include "mlx/distributed/ops.h"

mlx/backend/metal/fft.cpp

@@ -7,10 +7,10 @@
 
 #include "mlx/3rdparty/pocketfft.h"
 #include "mlx/backend/common/utils.h"
+#include "mlx/backend/gpu/copy.h"
+#include "mlx/backend/gpu/slicing.h"
 #include "mlx/backend/metal/binary.h"
-#include "mlx/backend/metal/copy.h"
 #include "mlx/backend/metal/kernels.h"
-#include "mlx/backend/metal/slicing.h"
 #include "mlx/backend/metal/unary.h"
 #include "mlx/backend/metal/utils.h"
 #include "mlx/utils.h"

mlx/backend/metal/hadamard.cpp

@@ -3,7 +3,7 @@
 #include "mlx/backend/common/hadamard.h"
 #include "mlx/backend/common/compiled.h"
 #include "mlx/backend/common/utils.h"
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/jit/includes.h"
 #include "mlx/backend/metal/kernels.h"

mlx/backend/metal/indexing.cpp

@@ -2,7 +2,7 @@
 #include <fmt/format.h>
 
 #include "mlx/backend/common/compiled.h"
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/jit/includes.h"
 #include "mlx/backend/metal/jit/indexing.h"

mlx/backend/metal/logsumexp.cpp

@@ -1,7 +1,7 @@
 // Copyright © 2023-2024 Apple Inc.
 #include <algorithm>
 
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/kernels.h"
 #include "mlx/backend/metal/utils.h"

mlx/backend/metal/matmul.cpp

@@ -7,7 +7,7 @@
 
 #include "mlx/backend/common/broadcasting.h"
 #include "mlx/backend/common/utils.h"
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/kernels.h"
 #include "mlx/backend/metal/kernels/defines.h"

mlx/backend/metal/normalization.cpp

@@ -1,7 +1,7 @@
 // Copyright © 2024 Apple Inc.
 #include <algorithm>
 
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/kernels/defines.h"
 #include "mlx/backend/metal/reduce.h"

mlx/backend/metal/primitives.cpp

@@ -7,10 +7,10 @@
 #include "mlx/backend/common/compiled.h"
 #include "mlx/backend/common/slicing.h"
 #include "mlx/backend/common/utils.h"
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
+#include "mlx/backend/gpu/slicing.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/kernels.h"
-#include "mlx/backend/metal/slicing.h"
 #include "mlx/backend/metal/utils.h"
 #include "mlx/primitives.h"
 #include "mlx/scheduler.h"
@@ -25,25 +25,6 @@ void arange_set_scalars(T start, T next, metal::CommandEncoder& enc) {
   enc.set_bytes(step, 1);
 }
 
-void reshape(const array& in, array& out, Stream s) {
-  auto [copy_necessary, out_strides] = prepare_reshape(in, out);
-  if (copy_necessary) {
-    out.set_data(allocator::malloc(out.nbytes()));
-    copy_gpu_inplace(
-        in,
-        out,
-        in.shape(),
-        in.strides(),
-        make_contiguous_strides(in.shape()),
-        0,
-        0,
-        CopyType::General,
-        s);
-  } else {
-    shared_buffer_reshape(in, out_strides, out);
-  }
-}
-
 static array compute_dynamic_offset(
     const array& indices,
     const Strides& strides,
@@ -226,105 +207,10 @@ void ArgReduce::eval_gpu(const std::vector<array>& inputs, array& out) {
   }
 }
 
-void AsType::eval_gpu(const std::vector<array>& inputs, array& out) {
-  CopyType ctype =
-      inputs[0].flags().contiguous ? CopyType::Vector : CopyType::General;
-  copy_gpu(inputs[0], out, ctype);
-}
-
-void AsStrided::eval_gpu(const std::vector<array>& inputs, array& out) {
-  eval(inputs, out);
-}
-
-void Broadcast::eval_gpu(const std::vector<array>& inputs, array& out) {
-  eval(inputs, out);
-}
-
-void BroadcastAxes::eval_gpu(const std::vector<array>& inputs, array& out) {
-  eval(inputs, out);
-}
-
-void Concatenate::eval_gpu(const std::vector<array>& inputs, array& out) {
-  concatenate_gpu(inputs, out, axis_, stream());
-}
-
-void Contiguous::eval_gpu(const std::vector<array>& inputs, array& out) {
-  assert(inputs.size() == 1);
-  auto& in = inputs[0];
-  constexpr size_t extra_bytes = 16384;
-  if (in.buffer_size() <= out.nbytes() + extra_bytes &&
-      (in.flags().row_contiguous ||
-       (allow_col_major_ && in.flags().col_contiguous))) {
-    out.copy_shared_buffer(in);
-  } else {
-    copy_gpu(in, out, CopyType::General);
-  }
-}
-
-void Copy::eval_gpu(const std::vector<array>& inputs, array& out) {
-  eval(inputs, out);
-}
-
-void CustomTransforms::eval_gpu(
-    const std::vector<array>& inputs,
-    std::vector<array>& outputs) {
-  eval(inputs, outputs);
-}
-
-void Depends::eval_gpu(
-    const std::vector<array>& inputs,
-    std::vector<array>& outputs) {
-  eval(inputs, outputs);
-}
-
-void Full::eval_gpu(const std::vector<array>& inputs, array& out) {
-  auto in = inputs[0];
-  CopyType ctype;
-  if (in.data_size() == 1) {
-    ctype = CopyType::Scalar;
-  } else if (in.flags().contiguous) {
-    ctype = CopyType::Vector;
-  } else {
-    ctype = CopyType::General;
-  }
-  copy_gpu(in, out, ctype);
-}
-
-void ExpandDims::eval_gpu(const std::vector<array>& inputs, array& out) {
-  eval(inputs, out);
-}
-
-void Flatten::eval_gpu(const std::vector<array>& inputs, array& out) {
-  reshape(inputs[0], out, stream());
-}
-
-void Unflatten::eval_gpu(const std::vector<array>& inputs, array& out) {
-  reshape(inputs[0], out, stream());
-}
-
 void Load::eval_gpu(const std::vector<array>& inputs, array& out) {
   throw std::runtime_error("[Load::eval_gpu] Not implemented.");
 }
 
-void NumberOfElements::eval_gpu(const std::vector<array>& inputs, array& out) {
-  eval(inputs, out);
-}
-
-void Pad::eval_gpu(const std::vector<array>& inputs, array& out) {
-  // Inputs must be base input array and scalar val array
-  assert(inputs.size() == 2);
-  auto& in = inputs[0];
-  auto& val = inputs[1];
-
-  // Padding value must be a scalar
-  assert(val.size() == 1);
-
-  // Padding value, input and output must be of the same type
-  assert(val.dtype() == in.dtype() && in.dtype() == out.dtype());
-
-  pad_gpu(in, val, out, axes_, low_pad_size_, stream());
-}
-
 void RandomBits::eval_gpu(const std::vector<array>& inputs, array& out) {
   assert(inputs.size() == 1);
 
@@ -370,27 +256,6 @@ void RandomBits::eval_gpu(const std::vector<array>& inputs, array& out) {
   compute_encoder.dispatch_threads(grid_dims, group_dims);
 }
 
-void Reshape::eval_gpu(const std::vector<array>& inputs, array& out) {
-  reshape(inputs[0], out, stream());
-}
-
-void Split::eval_gpu(
-    const std::vector<array>& inputs,
-    std::vector<array>& outputs) {
-  eval(inputs, outputs);
-}
-
-void Slice::eval_gpu(const std::vector<array>& inputs, array& out) {
-  assert(inputs.size() == 1);
-  if (out.size() == 0) {
-    out.set_data(nullptr);
-    return;
-  }
-
-  auto& in = inputs[0];
-  slice_gpu(in, out, start_indices_, strides_, stream());
-}
-
 void DynamicSlice::eval_gpu(const std::vector<array>& inputs, array& out) {
   if (out.size() == 0) {
     out.set_data(nullptr);
@@ -492,18 +357,6 @@ void SliceUpdate::eval_gpu(const std::vector<array>& inputs, array& out) {
       /* const Stream& s = */ stream());
 }
 
-void Squeeze::eval_gpu(const std::vector<array>& inputs, array& out) {
-  eval(inputs, out);
-}
-
-void StopGradient::eval_gpu(const std::vector<array>& inputs, array& out) {
-  eval(inputs, out);
-}
-
-void Transpose::eval_gpu(const std::vector<array>& inputs, array& out) {
-  eval(inputs, out);
-}
-
 void QRF::eval_gpu(
     const std::vector<array>& inputs,
     std::vector<array>& outputs) {
@@ -537,35 +390,4 @@ void LUF::eval_gpu(
   throw std::runtime_error("[LUF::eval_gpu] Metal LU factorization NYI.");
 }
 
-void View::eval_gpu(const std::vector<array>& inputs, array& out) {
-  auto& in = inputs[0];
-  auto ibytes = size_of(in.dtype());
-  auto obytes = size_of(out.dtype());
-  // Conditions for buffer copying (disjunction):
-  // - type size is the same
-  // - type size is smaller and the last axis is contiguous
-  // - the entire array is row contiguous
-  if (ibytes == obytes || (obytes < ibytes && in.strides().back() == 1) ||
-      in.flags().row_contiguous) {
-    auto strides = in.strides();
-    for (int i = 0; i < static_cast<int>(strides.size()) - 1; ++i) {
-      strides[i] *= ibytes;
-      strides[i] /= obytes;
-    }
-    out.copy_shared_buffer(
-        in, strides, in.flags(), in.data_size() * ibytes / obytes);
-  } else {
-    auto tmp = array(in.shape(), in.dtype(), nullptr, {});
-    tmp.set_data(allocator::malloc(tmp.nbytes()));
-    copy_gpu_inplace(in, tmp, CopyType::General, stream());
-
-    auto flags = out.flags();
-    flags.contiguous = true;
-    flags.row_contiguous = true;
-    auto max_dim = std::max_element(out.shape().begin(), out.shape().end());
-    flags.col_contiguous = out.size() <= 1 || out.size() == *max_dim;
-    out.copy_shared_buffer(tmp, out.strides(), flags, out.size());
-  }
-}
-
 } // namespace mlx::core

mlx/backend/metal/quantized.cpp

@@ -4,7 +4,7 @@
 
 #include "mlx/backend/common/broadcasting.h"
 #include "mlx/backend/common/compiled.h"
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/kernels.h"
 #include "mlx/backend/metal/reduce.h"

mlx/backend/metal/reduce.cpp

@@ -3,7 +3,7 @@
 #include <algorithm>
 #include <cassert>
 
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/kernels.h"
 #include "mlx/backend/metal/kernels/defines.h"

mlx/backend/metal/rope.cpp

@@ -1,5 +1,5 @@
 // Copyright © 2023-2024 Apple Inc.
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/utils.h"
 #include "mlx/fast_primitives.h"
 

mlx/backend/metal/scaled_dot_product_attention.cpp

@@ -2,7 +2,7 @@
 #include <sstream>
 
 #include "mlx/backend/common/compiled.h"
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 
 #include "mlx/backend/metal/kernels/steel/attn/params.h"

mlx/backend/metal/scan.cpp

@@ -3,7 +3,7 @@
 #include <cassert>
 #include <sstream>
 
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/kernels.h"
 #include "mlx/backend/metal/utils.h"

mlx/backend/metal/slicing.cpp

@@ -2,21 +2,12 @@
 
 #include <numeric>
 
-#include "mlx/backend/common/slicing.h"
+#include "mlx/backend/gpu/copy.h"
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/slicing.h"
 #include "mlx/backend/metal/device.h"
 
 namespace mlx::core {
 
-void slice_gpu(
-    const array& in,
-    array& out,
-    const Shape& start_indices,
-    const Shape& strides,
-    const Stream& s) {
-  slice(in, out, start_indices, strides);
-}
-
 void concatenate_gpu(
     const std::vector<array>& inputs,
     array& out,
@@ -48,30 +39,4 @@ void concatenate_gpu(
   }
 }
 
-void pad_gpu(
-    const array& in,
-    const array& val,
-    array& out,
-    const std::vector<int>& axes,
-    const Shape& low_pad_size,
-    const Stream& s) {
-  // Fill output with val
-  fill_gpu(val, out, s);
-
-  // Find offset for start of input values
-  size_t data_offset = 0;
-  for (int i = 0; i < axes.size(); i++) {
-    auto ax = axes[i] < 0 ? out.ndim() + axes[i] : axes[i];
-    data_offset += out.strides()[ax] * low_pad_size[i];
-  }
-
-  // Extract slice from output where input will be pasted
-  array out_slice(in.shape(), out.dtype(), nullptr, {});
-  out_slice.copy_shared_buffer(
-      out, out.strides(), out.flags(), out_slice.size(), data_offset);
-
-  // Copy input values into the slice
-  copy_gpu_inplace(in, out_slice, CopyType::GeneralGeneral, s);
-}
-
 } // namespace mlx::core

mlx/backend/metal/softmax.cpp

@@ -1,7 +1,7 @@
 // Copyright © 2023-2024 Apple Inc.
 #include <algorithm>
 
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/kernels.h"
 #include "mlx/backend/metal/kernels/defines.h"

mlx/backend/metal/sort.cpp

@@ -2,7 +2,7 @@
 
 #include <algorithm>
 
-#include "mlx/backend/metal/copy.h"
+#include "mlx/backend/gpu/copy.h"
 #include "mlx/backend/metal/device.h"
 #include "mlx/backend/metal/kernels.h"
 #include "mlx/backend/metal/utils.h"