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Update GEMM (#424)

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* Organize and collect metal subroutine templates and elements in `metal/kernels/steel/`
* Update gemm elements for better performance 
* Add split-K specialization for gemm
* Add `addmm` primitive, op and bindings for fused matmul and bias addition 
* Update tests and benchmarks as needed
This commit is contained in:
Jagrit Digani
2024-01-17 12:42:39 -08:00
committed by GitHub
parent 556cdf0e06
commit 78102a47ad
30 changed files with 2361 additions and 646 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
mlx/backend/metal/conv.cpp
View File

@@ -70,7 +70,7 @@ void explicit_gemm_conv_1D_gpu(
// Perform gemm
std::vector<array> copies = {in_padded, in_strided};
mlx_matmul(
return steel_matmul(
s,
d,
/*a = */ in_strided,
@@ -262,7 +262,7 @@ void explicit_gemm_conv_2D_gpu(
// Perform gemm
std::vector<array> copies = {in_padded, in_strided};
mlx_matmul(
return steel_matmul(
s,
d,
/*a = */ in_strided,
@@ -411,7 +411,7 @@ void winograd_conv_2D_gpu(
copies_w.push_back(out_wg);
{
std::vector<array> empty_copies;
mlx_matmul(
steel_matmul(
s,
d,
/*a = */ inp_wg,

37
mlx/backend/metal/kernels/CMakeLists.txt
View File

@@ -18,7 +18,6 @@ set(
"binary_two"
"conv"
"copy"
"gemm"
"gemv"
"quantized"
"random"
@@ -30,26 +29,27 @@ set(
"indexing"
)
function(build_kernel KERNEL)
set(SRCFILE ${CMAKE_CURRENT_SOURCE_DIR}/${KERNEL}.metal)
set(HEADERS_PADDED ${HEADERS})
if(${KERNEL} STREQUAL "gemm")
set(HEADERS_PADDED ${HEADERS_PADDED} ${CMAKE_CURRENT_SOURCE_DIR}/gemm/gemm.h)
endif()
if(${KERNEL} STREQUAL "conv")
set(HEADERS_PADDED ${HEADERS_PADDED} ${CMAKE_CURRENT_SOURCE_DIR}/gemm/conv.h)
endif()
function(build_kernel_base TARGET SRCFILE DEPS)
add_custom_command(
COMMAND xcrun -sdk macosx metal -Wall -Wextra
-fno-fast-math
-c ${SRCFILE}
-I${PROJECT_SOURCE_DIR}
-o ${KERNEL}.air
DEPENDS ${SRCFILE} ${HEADERS_PADDED}
OUTPUT ${KERNEL}.air
COMMENT "Building ${KERNEL}.air"
-o ${TARGET}.air
DEPENDS ${SRCFILE} ${DEPS}
OUTPUT ${TARGET}.air
COMMENT "Building ${TARGET}.air"
VERBATIM
)
endfunction(build_kernel_base)
function(build_kernel KERNEL)
set(SRCFILE ${CMAKE_CURRENT_SOURCE_DIR}/${KERNEL}.metal)
set(HEADERS_PADDED ${HEADERS})
if(${KERNEL} STREQUAL "conv")
set(HEADERS_PADDED ${HEADERS_PADDED} ${CMAKE_CURRENT_SOURCE_DIR}/conv.h)
endif()
build_kernel_base(${KERNEL} ${SRCFILE} "${HEADERS_PADDED}")
endfunction(build_kernel)
foreach(KERNEL ${KERNELS})
@@ -57,6 +57,15 @@ foreach(KERNEL ${KERNELS})
set(KERNEL_AIR ${KERNEL}.air ${KERNEL_AIR})
endforeach()
file(GLOB_RECURSE STEEL_KERNELS ${CMAKE_CURRENT_SOURCE_DIR}/steel/*.metal)
file(GLOB_RECURSE STEEL_HEADERS ${CMAKE_CURRENT_SOURCE_DIR}/steel/*.h)
foreach(KERNEL ${STEEL_KERNELS})
cmake_path(GET KERNEL STEM TARGET)
build_kernel_base(${TARGET} ${KERNEL} "${STEEL_HEADERS}")
set(KERNEL_AIR ${TARGET}.air ${KERNEL_AIR})
endforeach()
add_custom_command(
OUTPUT ${MLX_METAL_PATH}/mlx.metallib
COMMAND xcrun -sdk macosx metallib ${KERNEL_AIR} -o ${MLX_METAL_PATH}/mlx.metallib

0
mlx/backend/metal/kernels/gemm/conv.h → mlx/backend/metal/kernels/conv.h
View File

2
mlx/backend/metal/kernels/conv.metal
View File

@@ -5,7 +5,7 @@
#include "mlx/backend/metal/kernels/conv_params.h"
#include "mlx/backend/metal/kernels/bf16.h"
#include "mlx/backend/metal/kernels/gemm/conv.h"
#include "mlx/backend/metal/kernels/conv.h"
using namespace metal;

538
mlx/backend/metal/kernels/gemm/gemm.h
View File

@@ -1,538 +0,0 @@
// Copyright © 2023 Apple Inc.
#pragma once
#include <metal_simdgroup>
#include <metal_simdgroup_matrix>
#include <metal_stdlib>
#define MLX_MTL_CONST static constant constexpr const
using namespace metal;
///////////////////////////////////////////////////////////////////////////////
// Loading helper
///////////////////////////////////////////////////////////////////////////////
template <
typename T,
int BROWS,
int BCOLS,
int BK,
int vec_size,
int tgp_size,
bool transpose,
bool ldK,
int tgp_padding = 0>
struct BlockLoader {
// Destination dimensions
MLX_MTL_CONST int dst_fd = transpose ? BCOLS : BROWS;
MLX_MTL_CONST int dst_ld = (transpose ? BROWS : BCOLS) + tgp_padding;
MLX_MTL_CONST int n_vecs = (transpose ? BROWS : BCOLS) / vec_size;
// Stride along block row within the block
MLX_MTL_CONST int bstride = tgp_size / n_vecs;
// Leading dimension for src
const int src_ld;
// Stride along reduction axis between blocks
const int tstride;
// Thread location indices
const short thread_idx;
const short bi;
const short bj;
// threadgroup and device memory
threadgroup T* dst;
const device T* src;
/* Constructor */
METAL_FUNC BlockLoader(
const device T* src_,
const int src_ld_,
threadgroup T* dst_,
uint simd_group_id [[simdgroup_index_in_threadgroup]],
uint simd_lane_id [[thread_index_in_simdgroup]])
: src_ld(src_ld_),
tstride(
BK * ((int)(transpose ^ !ldK) * src_ld + (int)(transpose ^ ldK))),
thread_idx(simd_group_id * 32 + simd_lane_id),
bi(thread_idx / n_vecs),
bj(vec_size * (thread_idx % n_vecs)),
dst(dst_ + bi * dst_ld + bj),
src(src_ + bi * src_ld + bj) {}
/* Load from device memory into threadgroup memory - without bound checking */
METAL_FUNC void load_unsafe() const {
#pragma clang loop unroll(full)
for (short i = 0; i < dst_fd; i += bstride) {
#pragma clang loop unroll(full)
for (short j = 0; j < vec_size; j++) {
dst[i * dst_ld + j] = src[i * src_ld + j];
}
}
}
/* Load from device memory into threadgroup memory - with bound checking */
METAL_FUNC void load_safe(short2 src_tile_dim) const {
src_tile_dim = transpose ? src_tile_dim.yx : src_tile_dim.xy;
// Iterate over rows of block
#pragma clang loop unroll(full)
for (short i = 0; i < dst_fd; i += bstride) {
// Row is in bounds, we check against column
if ((bi + i) < src_tile_dim.y) {
// Use fast thread memory for bound checks
short tmp_idx[vec_size];
T tmp_val[vec_size];
// Make sure tmp_idx only contains valid indices
#pragma clang loop unroll(full)
for (short j = 0; j < vec_size; j++) {
tmp_idx[j] = bj + j < src_tile_dim.x ? j : 0;
}
// Read all valid indices into tmp_val
#pragma clang loop unroll(full)
for (short j = 0; j < vec_size; j++) {
tmp_val[j] = src[i * src_ld + tmp_idx[j]];
}
// Zero out unneeded values
#pragma clang loop unroll(full)
for (short j = 0; j < vec_size; j++) {
tmp_val[j] = bj + j < src_tile_dim.x ? tmp_val[j] : T(0);
}
// Copy values to threadgroup memory
#pragma clang loop unroll(full)
for (short j = 0; j < vec_size; j++) {
dst[i * dst_ld + j] = tmp_val[j];
}
}
// Row is out of bounds, we just fill tgp memory with zeros
else {
#pragma clang loop unroll(full)
for (short j = 0; j < vec_size; j++) {
dst[i * dst_ld + j] = T(0);
}
}
}
}
/* Iteration helper */
METAL_FUNC void next() {
src += tstride;
}
};
///////////////////////////////////////////////////////////////////////////////
// Transforms
///////////////////////////////////////////////////////////////////////////////
template <typename OutT, typename InT>
struct TransformNone {
static METAL_FUNC OutT apply(InT x) {
return static_cast<OutT>(x);
}
};
template <typename T>
struct AccumHelper {
typedef float accum_type;
};
///////////////////////////////////////////////////////////////////////////////
// MMA helper
///////////////////////////////////////////////////////////////////////////////
template <
typename T,
int BM,
int BN,
int BK,
int WM,
int WN,
bool transpose_a,
bool transpose_b,
int tgp_padding_a = 0,
int tgp_padding_b = 0,
typename AccumType = typename AccumHelper<T>::accum_type,
typename Epilogue = TransformNone<T, AccumType>>
struct BlockMMA {
// Warp tile size along M
MLX_MTL_CONST int TM = BM / (WM * 8);
// Warp tile size along N
MLX_MTL_CONST int TN = BN / (WN * 8);
// Warp tile simdgroup matrix strides along M
MLX_MTL_CONST int TM_stride = 8 * WM;
// Warp tile simdgroup matrix strides along M
MLX_MTL_CONST int TN_stride = 8 * WN;
// Leading dimensions of threadgroup A, B blocks
MLX_MTL_CONST int lda_tgp = (transpose_a ? BM : BK) + tgp_padding_a;
MLX_MTL_CONST int ldb_tgp = (transpose_b ? BK : BN) + tgp_padding_b;
// Strides of A, B along reduction axis
MLX_MTL_CONST short simd_stride_a =
transpose_a ? TM_stride : TM_stride * lda_tgp;
MLX_MTL_CONST short simd_stride_b =
transpose_b ? TN_stride * ldb_tgp : TN_stride;
// Jump between elements
MLX_MTL_CONST short jump_a = transpose_a ? lda_tgp : 1;
MLX_MTL_CONST short jump_b = transpose_b ? ldb_tgp : 1;
// Offsets within threadgroup
const int tm;
const int tn;
// Simdgroup matrices
simdgroup_matrix<AccumType, 8, 8> Asimd[TM];
simdgroup_matrix<AccumType, 8, 8> Bsimd[TN];
simdgroup_matrix<AccumType, 8, 8> results[TM * TN] = {
simdgroup_matrix<AccumType, 8, 8>(0)};
short sm;
short sn;
/* Constructor */
METAL_FUNC BlockMMA(
uint simd_group_id [[simdgroup_index_in_threadgroup]],
uint simd_lane_id [[thread_index_in_simdgroup]])
: tm(8 * (simd_group_id / WN)), tn(8 * (simd_group_id % WN)) {
short qid = simd_lane_id / 4;
sm = (qid & 4) + (simd_lane_id / 2) % 4;
sn = (qid & 2) * 2 + (simd_lane_id % 2) * 2;
}
/* (BM, BK) X (BK, BN) multiply accumulate function */
METAL_FUNC void mma(const threadgroup T* As, const threadgroup T* Bs) {
// Iterate over BK in blocks of 8
#pragma clang loop unroll(full)
for (short kk = 0; kk < BK; kk += 8) {
short2 offset_a =
transpose_a ? short2(tm + sm, kk + sn) : short2(kk + sn, tm + sm);
short2 offset_b =
transpose_b ? short2(kk + sm, tn + sn) : short2(tn + sn, kk + sm);
const threadgroup T* As__ = As + offset_a.y * lda_tgp + offset_a.x;
const threadgroup T* Bs__ = Bs + offset_b.y * ldb_tgp + offset_b.x;
simdgroup_barrier(mem_flags::mem_none);
// Load elements from threadgroup A as simdgroup matrices
#pragma clang loop unroll(full)
for (short i = 0; i < TM; i++) {
Asimd[i].thread_elements()[0] = static_cast<AccumType>(As__[0]);
Asimd[i].thread_elements()[1] = static_cast<AccumType>(As__[jump_a]);
As__ += simd_stride_a;
}
simdgroup_barrier(mem_flags::mem_none);
// Load elements from threadgroup B as simdgroup matrices
#pragma clang loop unroll(full)
for (short j = 0; j < TN; j++) {
Bsimd[j].thread_elements()[0] = static_cast<AccumType>(Bs__[0]);
Bsimd[j].thread_elements()[1] = static_cast<AccumType>(Bs__[jump_b]);
Bs__ += simd_stride_b;
}
simdgroup_barrier(mem_flags::mem_none);
// Multiply and accumulate into result simdgroup matrices
#pragma clang loop unroll(full)
for (short i = 0; i < TM; i++) {
#pragma clang loop unroll(full)
for (short j = 0; j < TN; j++) {
simdgroup_multiply_accumulate(
results[i * TN + j], Asimd[i], Bsimd[j], results[i * TN + j]);
}
}
}
}
/* Store results from simdgroup_matrix results into device memory */
METAL_FUNC void store_result(device T* C, const int ldc) const {
#pragma clang loop unroll(full)
for (int i = 0; i < TM; i++) {
#pragma clang loop unroll(full)
for (int j = 0; j < TN; j++) {
C[(i * TM_stride + sm + tm) * ldc + j * TN_stride + tn + sn] =
Epilogue::apply(results[i * TN + j].thread_elements()[0]);
C[(i * TM_stride + sm + tm) * ldc + j * TN_stride + tn + sn + 1] =
Epilogue::apply(results[i * TN + j].thread_elements()[1]);
}
}
}
METAL_FUNC void
store_result_safe(device T* C, const int ldc, short2 dst_tile_dims) const {
#pragma clang loop unroll(full)
for (int i = 0; i < TM; i++) {
if (tm + i * TM_stride + sm < dst_tile_dims.y) {
#pragma clang loop unroll(full)
for (int j = 0; j < TN; j++) {
if (tn + j * TN_stride + sn < dst_tile_dims.x) {
C[(tm + i * TM_stride + sm) * ldc + tn + j * TN_stride + sn] =
Epilogue::apply(results[i * TN + j].thread_elements()[0]);
}
if (tn + j * TN_stride + sn + 1 < dst_tile_dims.x) {
C[(tm + i * TM_stride + sm) * ldc + tn + j * TN_stride + sn + 1] =
Epilogue::apply(results[i * TN + j].thread_elements()[1]);
}
}
}
}
}
};
///////////////////////////////////////////////////////////////////////////////
// GEMM kernels
///////////////////////////////////////////////////////////////////////////////
template <
typename T,
int BM,
int BN,
int BK,
int WM,
int WN,
bool transpose_a,
bool transpose_b,
bool MN_aligned,
bool K_aligned,
typename AccumType = typename AccumHelper<T>::accum_type,
typename Epilogue = TransformNone<T, AccumType>>
struct GEMMKernel {
MLX_MTL_CONST short tgp_padding_a = 16 / sizeof(T);
MLX_MTL_CONST short tgp_padding_b = 16 / sizeof(T);
MLX_MTL_CONST short tgp_mem_size_a =
transpose_a ? BK * (BM + tgp_padding_a) : BM * (BK + tgp_padding_a);
MLX_MTL_CONST short tgp_mem_size_b =
transpose_b ? BN * (BK + tgp_padding_b) : BK * (BN + tgp_padding_b);
MLX_MTL_CONST short tgp_mem_size = tgp_mem_size_a + tgp_mem_size_b;
MLX_MTL_CONST short tgp_size = WM * WN * 32;
MLX_MTL_CONST short vec_size = (BM == 64 && BN == 64) ? 8 : 4;
using loader_a_t = BlockLoader<
T,
BM,
BK,
BK,
vec_size,
tgp_size,
transpose_a,
true,
tgp_padding_a>;
using loader_b_t = BlockLoader<
T,
BK,
BN,
BK,
vec_size,
tgp_size,
transpose_b,
false,
tgp_padding_b>;
using mma_t = BlockMMA<
T,
BM,
BN,
BK,
WM,
WN,
transpose_a,
transpose_b,
tgp_padding_a,
tgp_padding_b,
AccumType,
Epilogue>;
/* Main kernel function */
static METAL_FUNC void run(
const device T* A [[buffer(0)]],
const device T* B [[buffer(1)]],
device T* C [[buffer(2)]],
const constant int& M [[buffer(3)]],
const constant int& N [[buffer(4)]],
const constant int& K [[buffer(5)]],
const constant int& batch_stride_a [[buffer(6)]],
const constant int& batch_stride_b [[buffer(7)]],
const constant int& batch_stride_c [[buffer(8)]],
threadgroup T* tgp_memory [[threadgroup(0)]],
uint simd_lane_id [[thread_index_in_simdgroup]],
uint simd_group_id [[simdgroup_index_in_threadgroup]],
uint3 tid [[threadgroup_position_in_grid]],
uint3 lid [[thread_position_in_threadgroup]]) {
// Pacifying compiler
(void)lid;
// Adjust for batch
A += batch_stride_a * tid.z;
B += batch_stride_b * tid.z;
C += batch_stride_c * tid.z;
// Adjust for transpose
const int lda_dev = transpose_a ? M : K;
const int ldb_dev = transpose_b ? K : N;
// Find block in A, B, C
const int c_row = tid.y * BM;
const int c_col = tid.x * BN;
A += transpose_a ? c_row : c_row * K;
B += transpose_b ? c_col * K : c_col;
C += c_row * N + c_col;
// Prepare threadgroup memory for loading
threadgroup T* As = tgp_memory;
threadgroup T* Bs = tgp_memory + tgp_mem_size_a;
// Prepare threadgroup loading operations
loader_a_t loader_a(A, lda_dev, As, simd_group_id, simd_lane_id);
loader_b_t loader_b(B, ldb_dev, Bs, simd_group_id, simd_lane_id);
// Prepare threadgroup mma operation
mma_t mma_op(simd_group_id, simd_lane_id);
///////////////////////////////////////////////////////////////////////////////
// MNK aligned loop
if (MN_aligned && K_aligned) {
for (int k = 0; k < K; k += BK) {
threadgroup_barrier(mem_flags::mem_threadgroup);
// Load elements into threadgroup
loader_a.load_unsafe();
loader_b.load_unsafe();
threadgroup_barrier(mem_flags::mem_threadgroup);
// Multiply and accumulate threadgroup elements
mma_op.mma(As, Bs);
// Prepare for next iteration
loader_a.next();
loader_b.next();
}
threadgroup_barrier(mem_flags::mem_none);
// Store results to device memory
mma_op.store_result(C, N);
return;
}
///////////////////////////////////////////////////////////////////////////////
// MN aligned, K unaligned loop
else if (MN_aligned && !K_aligned) {
// Main loop
int k = 0;
for (; k + BK <= K; k += BK) {
threadgroup_barrier(mem_flags::mem_threadgroup);
// Load elements into threadgroup
loader_a.load_unsafe();
loader_b.load_unsafe();
threadgroup_barrier(mem_flags::mem_threadgroup);
// Multiply and accumulate threadgroup elements
mma_op.mma(As, Bs);
// Prepare for next iteration
loader_a.next();
loader_b.next();
}
// Loop tail
threadgroup_barrier(mem_flags::mem_threadgroup);
loader_a.load_safe(short2(K - k, BM));
loader_b.load_safe(short2(BN, K - k));
threadgroup_barrier(mem_flags::mem_threadgroup);
mma_op.mma(As, Bs);
// Store results to device memory
mma_op.store_result(C, N);
return;
}
///////////////////////////////////////////////////////////////////////////////
// MNK unaligned loop
else { // Loop over K - unaligned case
short2 src_tile_dims(min(BN, N - c_col), min(BM, M - c_row));
if (src_tile_dims.y == BM && src_tile_dims.x == BN) {
int k = 0;
for (; k + BK <= K; k += BK) {
threadgroup_barrier(mem_flags::mem_threadgroup);
// Load elements into threadgroup
loader_a.load_unsafe();
loader_b.load_unsafe();
threadgroup_barrier(mem_flags::mem_threadgroup);
// Multiply and accumulate threadgroup elements
mma_op.mma(As, Bs);
// Prepare for next iteration
loader_a.next();
loader_b.next();
}
threadgroup_barrier(mem_flags::mem_none);
if (k < K) {
loader_a.load_safe(short2(K - k, BM));
loader_b.load_safe(short2(BN, K - k));
threadgroup_barrier(mem_flags::mem_threadgroup);
mma_op.mma(As, Bs);
}
mma_op.store_result(C, N);
return;
} else {
int k = 0;
for (; k + BK <= K; k += BK) {
threadgroup_barrier(mem_flags::mem_threadgroup);
// Load elements into threadgroup
loader_a.load_safe(short2(BK, src_tile_dims.y));
loader_b.load_safe(short2(src_tile_dims.x, BK));
threadgroup_barrier(mem_flags::mem_threadgroup);
// Multiply and accumulate threadgroup elements
mma_op.mma(As, Bs);
// Prepare for next iteration
loader_a.next();
loader_b.next();
}
threadgroup_barrier(mem_flags::mem_none);
if (k < K) {
loader_a.load_safe(short2(K - k, src_tile_dims.y));
loader_b.load_safe(short2(src_tile_dims.x, K - k));
threadgroup_barrier(mem_flags::mem_threadgroup);
mma_op.mma(As, Bs);
}
threadgroup_barrier(mem_flags::mem_none);
mma_op.store_result_safe(C, N, src_tile_dims);
return;
}
}
}
};

12
mlx/backend/metal/kernels/quantized.metal
View File

@@ -5,9 +5,10 @@
#include "mlx/backend/metal/kernels/bf16.h"
#include "mlx/backend/metal/kernels/defines.h"
#include "mlx/backend/metal/kernels/gemm/gemm.h"
#include "mlx/backend/metal/kernels/utils.h"
#include "mlx/backend/metal/kernels/steel/gemm/gemm.h"
using namespace metal;
#define MLX_MTL_CONST static constant constexpr const
@@ -239,8 +240,9 @@ template <typename T, const int BM, const int BK, const int BN, const int group_
constexpr int w_els_per_thread = (BN * BK / el_per_int) / (SIMD_SIZE * WM * WN);
// Instantiate the appropriate BlockMMA and Loader
using mma_t = BlockMMA<T, BM, BN, BK, WM, WN, false, true>;
using loader_x_t = BlockLoader<T, BM, BK, BK, 4, WM * WN * SIMD_SIZE, false, true, 0>;
using mma_t = mlx::steel::BlockMMA<T, T, BM, BN, BK, WM, WN, false, true, BK, BK>;
using loader_x_t = mlx::steel::BlockLoader<T, BM, BK, BK, 1, WM * WN * SIMD_SIZE, 1, 4>;
threadgroup T scales_block[BN * groups_per_block];
threadgroup T biases_block[BN * groups_per_block];
@@ -392,8 +394,8 @@ template <typename T, const int BM, const int BK, const int BN, const int group_
constexpr int w_els_per_thread = (BK * BN / el_per_int) / (SIMD_SIZE * WM * WN);
// Instantiate the appropriate BlockMMA and Loader
using mma_t = BlockMMA<T, BM, BN, BK, WM, WN, false, false>;
using loader_x_t = BlockLoader<T, BM, BK, BK, 4, WM * WN * SIMD_SIZE, false, true, 0>;
using mma_t = mlx::steel::BlockMMA<T, T, BM, BN, BK, WM, WN, false, false, BK, BN>;
using loader_x_t = mlx::steel::BlockLoader<T, BM, BK, BK, 1, WM * WN * SIMD_SIZE, 1, 4>;
threadgroup T scales_block[BK * groups_per_block];
threadgroup T biases_block[BK * groups_per_block];

312
mlx/backend/metal/kernels/steel/gemm/gemm.h Normal file
View File

@@ -0,0 +1,312 @@
// Copyright © 2024 Apple Inc.
#pragma once
#include "mlx/backend/metal/kernels/steel/gemm/loader.h"
#include "mlx/backend/metal/kernels/steel/gemm/mma.h"
#include "mlx/backend/metal/kernels/steel/gemm/transforms.h"
#include "mlx/backend/metal/kernels/steel/utils.h"
using namespace metal;
///////////////////////////////////////////////////////////////////////////////
// GEMM kernel class
///////////////////////////////////////////////////////////////////////////////
namespace mlx {
namespace steel {
template <bool M_aligned, bool N_aligned, bool K_aligned>
struct LoopAlignment {};
template <
typename T,
typename U,
int BM,
int BN,
int BK,
int WM,
int WN,
bool transpose_a,
bool transpose_b,
bool MN_aligned,
bool K_aligned,
typename AccumType = typename AccumHelper<T>::accum_type,
typename Epilogue = TransformNone<U, AccumType>>
struct GEMMKernel {
STEEL_CONST short tgp_padding_a = 16 / sizeof(T);
STEEL_CONST short tgp_padding_b = 16 / sizeof(T);
STEEL_CONST short tgp_mem_size_a =
transpose_a ? BK * (BM + tgp_padding_a) : BM * (BK + tgp_padding_a);
STEEL_CONST short tgp_mem_size_b =
transpose_b ? BN * (BK + tgp_padding_b) : BK * (BN + tgp_padding_b);
STEEL_CONST short tgp_mem_size = tgp_mem_size_a + tgp_mem_size_b;
STEEL_CONST short tgp_size = WM * WN * 32;
using loader_a_t = BlockLoader<
T,
transpose_a ? BK : BM,
transpose_a ? BM : BK,
transpose_a ? BM + tgp_padding_a : BK + tgp_padding_a,
!transpose_a,
tgp_size>;
using loader_b_t = BlockLoader<
T,
transpose_b ? BN : BK,
transpose_b ? BK : BN,
transpose_b ? BK + tgp_padding_b : BN + tgp_padding_b,
transpose_b,
tgp_size>;
using mma_t = BlockMMA<
T,
U,
BM,
BN,
BK,
WM,
WN,
transpose_a,
transpose_b,
transpose_a ? BM + tgp_padding_a : BK + tgp_padding_a,
transpose_b ? BK + tgp_padding_b : BN + tgp_padding_b,
AccumType,
Epilogue>;
/* Main kernel function */
template <bool M_aligned, bool N_aligned, bool K_aligned_>
static METAL_FUNC void gemm_loop(
threadgroup T* As [[threadgroup(0)]],
threadgroup T* Bs [[threadgroup(1)]],
const int gemm_k_iterations,
thread loader_a_t& loader_a,
thread loader_b_t& loader_b,
thread mma_t& mma_op,
thread const short& tgp_bm,
thread const short& tgp_bn,
thread const short& lbk,
LoopAlignment<M_aligned, N_aligned, K_aligned_> l = {}) {
// Appease the compiler
(void)l;
thread bool mask_A[loader_a_t::n_rows][loader_a_t::vec_size];
thread bool mask_B[loader_b_t::n_rows][loader_b_t::vec_size];
if (!M_aligned) {
short2 tile_dims_A =
transpose_a ? short2(tgp_bm, BK) : short2(BK, tgp_bm);
loader_a.set_mask(tile_dims_A, mask_A);
}
if (!N_aligned) {
short2 tile_dims_B =
transpose_b ? short2(BK, tgp_bn) : short2(tgp_bn, BK);
loader_b.set_mask(tile_dims_B, mask_B);
}
for (int k = 0; k < gemm_k_iterations; k++) {
threadgroup_barrier(mem_flags::mem_threadgroup);
// Load elements into threadgroup
if (M_aligned) {
loader_a.load_unsafe();
} else {
loader_a.load_safe(mask_A);
}
if (N_aligned) {
loader_b.load_unsafe();
} else {
loader_b.load_safe(mask_B);
}
threadgroup_barrier(mem_flags::mem_threadgroup);
// Multiply and accumulate threadgroup elements
mma_op.mma(As, Bs);
// Prepare for next iteration
loader_a.next();
loader_b.next();
}
if (!K_aligned_) {
threadgroup_barrier(mem_flags::mem_threadgroup);
short2 tile_dims_A_last =
transpose_a ? short2(tgp_bm, lbk) : short2(lbk, tgp_bm);
short2 tile_dims_B_last =
transpose_b ? short2(lbk, tgp_bn) : short2(tgp_bn, lbk);
loader_a.set_mask(tile_dims_A_last, mask_A);
loader_b.set_mask(tile_dims_B_last, mask_B);
loader_a.load_safe(mask_A);
loader_b.load_safe(mask_B);
threadgroup_barrier(mem_flags::mem_threadgroup);
mma_op.mma(As, Bs);
}
}
/* Main kernel function */
static METAL_FUNC void run(
const device T* A [[buffer(0)]],
const device T* B [[buffer(1)]],
device U* C [[buffer(2)]],
const constant GEMMParams* params [[buffer(3)]],
threadgroup T* As [[threadgroup(0)]],
threadgroup T* Bs [[threadgroup(1)]],
uint simd_lane_id [[thread_index_in_simdgroup]],
uint simd_group_id [[simdgroup_index_in_threadgroup]],
uint3 tid [[threadgroup_position_in_grid]],
uint3 lid [[thread_position_in_threadgroup]]) {
// Pacifying compiler
(void)lid;
const int tid_y = ((tid.y) << params->swizzle_log) +
((tid.x) & ((1 << params->swizzle_log) - 1));
const int tid_x = (tid.x) >> params->swizzle_log;
if (params->tiles_n <= tid_x || params->tiles_m <= tid_y) {
return;
}
threadgroup_barrier(mem_flags::mem_none);
// Find block in A, B, C
const int c_row = tid_y * BM;
const int c_col = tid_x * BN;
A += transpose_a ? c_row : c_row * params->lda;
B += transpose_b ? c_col * params->ldb : c_col;
C += c_row * params->ldc + c_col;
// Prepare threadgroup loading operations
thread loader_a_t loader_a(A, params->lda, As, simd_group_id, simd_lane_id);
thread loader_b_t loader_b(B, params->ldb, Bs, simd_group_id, simd_lane_id);
// Prepare threadgroup mma operation
thread mma_t mma_op(simd_group_id, simd_lane_id);
int gemm_k_iterations = params->gemm_k_iterations_aligned;
///////////////////////////////////////////////////////////////////////////////
// MNK aligned loop
if (MN_aligned) {
for (int k = 0; k < gemm_k_iterations; k++) {
threadgroup_barrier(mem_flags::mem_threadgroup);
// Load elements into threadgroup
loader_a.load_unsafe();
loader_b.load_unsafe();
threadgroup_barrier(mem_flags::mem_threadgroup);
// Multiply and accumulate threadgroup elements
mma_op.mma(As, Bs);
// Prepare for next iteration
loader_a.next();
loader_b.next();
}
threadgroup_barrier(mem_flags::mem_none);
// Loop tail
if (!K_aligned) {
int lbk = params->K - params->gemm_k_iterations_aligned * BK;
short2 tile_dims_A = transpose_a ? short2(BM, lbk) : short2(lbk, BM);
short2 tile_dims_B = transpose_b ? short2(lbk, BN) : short2(BN, lbk);
thread bool mask_A[loader_a_t::n_rows][loader_a_t::vec_size];
thread bool mask_B[loader_b_t::n_rows][loader_b_t::vec_size];
loader_a.set_mask(tile_dims_A, mask_A);
loader_b.set_mask(tile_dims_B, mask_B);
loader_a.load_safe(mask_A);
loader_b.load_safe(mask_B);
threadgroup_barrier(mem_flags::mem_threadgroup);
mma_op.mma(As, Bs);
}
// Store results to device memory
mma_op.store_result(C, params->ldc);
return;
}
///////////////////////////////////////////////////////////////////////////////
// MN unaligned loop
else { // Loop over K - unaligned case
short tgp_bm = min(BM, params->M - c_row);
short tgp_bn = min(BN, params->N - c_col);
short leftover_bk = params->K - params->gemm_k_iterations_aligned * BK;
if (tgp_bm == BM && tgp_bn == BN) {
gemm_loop<true, true, K_aligned>(
As,
Bs,
gemm_k_iterations,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk);
mma_op.store_result(C, params->ldc);
return;
} else if (tgp_bn == BN) {
gemm_loop<false, true, K_aligned>(
As,
Bs,
gemm_k_iterations,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk);
mma_op.store_result_safe(C, params->ldc, short2(tgp_bn, tgp_bm));
return;
} else if (tgp_bm == BM) {
gemm_loop<true, false, K_aligned>(
As,
Bs,
gemm_k_iterations,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk);
mma_op.store_result_safe(C, params->ldc, short2(tgp_bn, tgp_bm));
return;
} else {
gemm_loop<false, false, K_aligned>(
As,
Bs,
gemm_k_iterations,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk);
mma_op.store_result_safe(C, params->ldc, short2(tgp_bn, tgp_bm));
return;
}
}
}
};
} // namespace steel
} // namespace mlx

44
mlx/backend/metal/kernels/gemm.metal → mlx/backend/metal/kernels/steel/gemm/kernels/steel_gemm.metal
View File

@@ -1,9 +1,10 @@
// Copyright © 2023 Apple Inc.
// Copyright © 2024 Apple Inc.
#include "mlx/backend/metal/kernels/bf16.h"
#include "mlx/backend/metal/kernels/gemm/gemm.h"
#include "mlx/backend/metal/kernels/steel/gemm/gemm.h"
using namespace metal;
using namespace mlx::steel;
///////////////////////////////////////////////////////////////////////////////
// GEMM kernels
@@ -23,26 +24,26 @@ template <typename T,
const device T *A [[buffer(0)]],
const device T *B [[buffer(1)]],
device T *C [[buffer(2)]],
const constant int &M [[buffer(3)]],
const constant int &N [[buffer(4)]],
const constant int &K [[buffer(5)]],
const constant int &batch_stride_a [[buffer(6)]],
const constant int &batch_stride_b [[buffer(7)]],
const constant int &batch_stride_c [[buffer(8)]],
const constant GEMMParams* params [[buffer(3)]],
uint simd_lane_id [[thread_index_in_simdgroup]],
uint simd_group_id [[simdgroup_index_in_threadgroup]],
uint3 tid [[threadgroup_position_in_grid]],
uint3 lid [[thread_position_in_threadgroup]]) {
uint3 lid [[thread_position_in_threadgroup]]) {
using gemm_kernel = GEMMKernel<T, BM, BN, BK, WM, WN, transpose_a, transpose_b, MN_aligned, K_aligned>;
using gemm_kernel = GEMMKernel<T, T, BM, BN, BK, WM, WN, transpose_a, transpose_b, MN_aligned, K_aligned>;
threadgroup T tgp_memory[gemm_kernel::tgp_mem_size];
threadgroup T As[gemm_kernel::tgp_mem_size_a];
threadgroup T Bs[gemm_kernel::tgp_mem_size_b];
// Adjust for batch
A += params->batch_stride_a * tid.z;
B += params->batch_stride_b * tid.z;
C += params->batch_stride_c * tid.z;
gemm_kernel::run(
A, B, C,
M, N, K,
batch_stride_a, batch_stride_b, batch_stride_c,
tgp_memory,
params,
As, Bs,
simd_lane_id, simd_group_id, tid, lid
);
}
@@ -52,17 +53,12 @@ template <typename T,
///////////////////////////////////////////////////////////////////////////////
#define instantiate_gemm(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, aname, mn_aligned, kname, k_aligned) \
template [[host_name("gemm_" #tname "_" #iname "_" #oname "_bm" #bm "_bn" #bn "_bk" #bk "_wm" #wm "_wn" #wn "_MN_" #aname "_K_" #kname)]] \
template [[host_name("steel_gemm_" #tname "_" #iname "_" #oname "_bm" #bm "_bn" #bn "_bk" #bk "_wm" #wm "_wn" #wn "_MN_" #aname "_K_" #kname)]] \
[[kernel]] void gemm<itype, bm, bn, bk, wm, wn, trans_a, trans_b, mn_aligned, k_aligned>( \
const device itype *A [[buffer(0)]], \
const device itype *B [[buffer(1)]], \
device itype *C [[buffer(2)]], \
const constant int &M [[buffer(3)]], \
const constant int &N [[buffer(4)]], \
const constant int &K [[buffer(5)]], \
const constant int &batch_stride_a [[buffer(6)]], \
const constant int &batch_stride_b [[buffer(7)]], \
const constant int &batch_stride_c [[buffer(8)]], \
const constant GEMMParams* params [[buffer(3)]], \
uint simd_lane_id [[thread_index_in_simdgroup]], \
uint simd_group_id [[simdgroup_index_in_threadgroup]], \
uint3 tid [[threadgroup_position_in_grid]], \
@@ -84,10 +80,10 @@ template <typename T,
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 32, 32, 16, 2, 2) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 64, 64, 16, 2, 2) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 64, 32, 32, 2, 2) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 64, 32, 16, 2, 2)
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 64, 32, 16, 2, 2) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 32, 64, 16, 2, 2)
instantiate_gemm_shapes_helper(float16, half, float16, half);
instantiate_gemm_shapes_helper(float32, float, float32, float);
instantiate_gemm_shapes_helper(bfloat16, bfloat16_t, bfloat16, bfloat16_t);
// TODO: Accumulation in different type
instantiate_gemm_shapes_helper(float32, float, float32, float);

260
mlx/backend/metal/kernels/steel/gemm/kernels/steel_gemm_addmm.metal Normal file
View File

@@ -0,0 +1,260 @@
// Copyright © 2024 Apple Inc.
#include "mlx/backend/metal/kernels/bf16.h"
#include "mlx/backend/metal/kernels/steel/gemm/gemm.h"
using namespace metal;
using namespace mlx::steel;
///////////////////////////////////////////////////////////////////////////////
// GEMM kernels
///////////////////////////////////////////////////////////////////////////////
template <typename T,
int BM,
int BN,
int BK,
int WM,
int WN,
bool transpose_a,
bool transpose_b,
bool MN_aligned,
bool K_aligned,
typename AccumType = float,
typename Epilogue = TransformAdd<T, AccumType>>
[[kernel, max_total_threads_per_threadgroup(WM * WN * 32)]] void addmm(
const device T *A [[buffer(0)]],
const device T *B [[buffer(1)]],
const device T *C [[buffer(2)]],
device T *D [[buffer(3)]],
const constant GEMMAddMMParams* params [[buffer(4)]],
uint simd_lane_id [[thread_index_in_simdgroup]],
uint simd_group_id [[simdgroup_index_in_threadgroup]],
uint3 tid [[threadgroup_position_in_grid]],
uint3 lid [[thread_position_in_threadgroup]]) {
// Pacifying compiler
(void)lid;
using gemm_kernel =
GEMMKernel<T, T, BM, BN, BK, WM, WN,
transpose_a, transpose_b,
MN_aligned, K_aligned,
AccumType, Epilogue>;
using loader_a_t = typename gemm_kernel::loader_a_t;
using loader_b_t = typename gemm_kernel::loader_b_t;
using mma_t = typename gemm_kernel::mma_t;
threadgroup T As[gemm_kernel::tgp_mem_size_a];
threadgroup T Bs[gemm_kernel::tgp_mem_size_b];
// Adjust for batch
A += params->batch_stride_a * tid.z;
B += params->batch_stride_b * tid.z;
C += params->batch_stride_c * tid.z;
D += params->batch_stride_d * tid.z;
const int tid_y = ((tid.y) << params->swizzle_log) +
((tid.x) & ((1 << params->swizzle_log) - 1));
const int tid_x = (tid.x) >> params->swizzle_log;
if (params->tiles_n <= tid_x || params->tiles_m <= tid_y) {
return;
}
threadgroup_barrier(mem_flags::mem_none);
// Find block in A, B, C
const int c_row = tid_y * BM;
const int c_col = tid_x * BN;
A += transpose_a ? c_row : c_row * params->lda;
B += transpose_b ? c_col * params->ldb : c_col;
C += c_row * params->ldc + c_col * params->fdc;
D += c_row * params->ldd + c_col;
// Prepare threadgroup loading operations
thread loader_a_t loader_a(A, params->lda, As, simd_group_id, simd_lane_id);
thread loader_b_t loader_b(B, params->ldb, Bs, simd_group_id, simd_lane_id);
// Prepare threadgroup mma operation
thread mma_t mma_op(simd_group_id, simd_lane_id);
int gemm_k_iterations = params->gemm_k_iterations_aligned;
const Epilogue epilogue_op(params->alpha, params->beta);
///////////////////////////////////////////////////////////////////////////////
// MNK aligned loop
if (MN_aligned) {
for (int k = 0; k < gemm_k_iterations; k++) {
threadgroup_barrier(mem_flags::mem_threadgroup);
// Load elements into threadgroup
loader_a.load_unsafe();
loader_b.load_unsafe();
threadgroup_barrier(mem_flags::mem_threadgroup);
// Multiply and accumulate threadgroup elements
mma_op.mma(As, Bs);
// Prepare for next iteration
loader_a.next();
loader_b.next();
}
threadgroup_barrier(mem_flags::mem_none);
// Loop tail
if (!K_aligned) {
int lbk = params->K - params->gemm_k_iterations_aligned * BK;
short2 tile_dims_A = transpose_a ? short2(BM, lbk) : short2(lbk, BM);
short2 tile_dims_B = transpose_b ? short2(lbk, BN) : short2(BN, lbk);
thread bool mask_A[loader_a_t::n_rows][loader_a_t::vec_size];
thread bool mask_B[loader_b_t::n_rows][loader_b_t::vec_size];
loader_a.set_mask(tile_dims_A, mask_A);
loader_b.set_mask(tile_dims_B, mask_B);
loader_a.load_safe(mask_A);
loader_b.load_safe(mask_B);
threadgroup_barrier(mem_flags::mem_threadgroup);
mma_op.mma(As, Bs);
}
// Store results to device memory
mma_op.store_result(D, params->ldd, C, params->ldc, params->fdc, epilogue_op);
return;
}
///////////////////////////////////////////////////////////////////////////////
// MN unaligned loop
else { // Loop over K - unaligned case
short tgp_bm = min(BM, params->M - c_row);
short tgp_bn = min(BN, params->N - c_col);
short leftover_bk = params->K - params->gemm_k_iterations_aligned * BK;
if (tgp_bm == BM && tgp_bn == BN) {
gemm_kernel::gemm_loop(
As,
Bs,
gemm_k_iterations,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk,
LoopAlignment<true, true, K_aligned>{});
mma_op.store_result(D, params->ldd, C, params->ldc, params->fdc, epilogue_op);
return;
} else if (tgp_bn == BN) {
gemm_kernel::gemm_loop(
As,
Bs,
gemm_k_iterations,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk,
LoopAlignment<false, true, K_aligned>{});
return mma_op.store_result_safe(
D, params->ldd,
C, params->ldc, params->fdc,
short2(tgp_bn, tgp_bm),
epilogue_op);
} else if (tgp_bm == BM) {
gemm_kernel::gemm_loop(
As,
Bs,
gemm_k_iterations,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk,
LoopAlignment<true, false, K_aligned>{});
return mma_op.store_result_safe(
D, params->ldd,
C, params->ldc, params->fdc,
short2(tgp_bn, tgp_bm),
epilogue_op);
} else {
gemm_kernel::gemm_loop(
As,
Bs,
gemm_k_iterations,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk,
LoopAlignment<false, false, K_aligned>{});
return mma_op.store_result_safe(
D, params->ldd,
C, params->ldc, params->fdc,
short2(tgp_bn, tgp_bm),
epilogue_op);
}
}
}
///////////////////////////////////////////////////////////////////////////////
// GEMM kernel initializations
///////////////////////////////////////////////////////////////////////////////
#define instantiate_gemm(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, aname, mn_aligned, kname, k_aligned, ep_name, epilogue) \
template [[host_name("steel_addmm_" #tname "_" #iname "_" #oname "_bm" #bm "_bn" #bn "_bk" #bk "_wm" #wm "_wn" #wn "_MN_" #aname "_K_" #kname "_" #ep_name)]] \
[[kernel]] void addmm<itype, bm, bn, bk, wm, wn, trans_a, trans_b, mn_aligned, k_aligned, float, epilogue<itype, float>>( \
const device itype *A [[buffer(0)]], \
const device itype *B [[buffer(1)]], \
const device itype *C [[buffer(2)]], \
device itype *D [[buffer(3)]], \
const constant GEMMAddMMParams* params [[buffer(4)]], \
uint simd_lane_id [[thread_index_in_simdgroup]], \
uint simd_group_id [[simdgroup_index_in_threadgroup]], \
uint3 tid [[threadgroup_position_in_grid]], \
uint3 lid [[thread_position_in_threadgroup]]);
#define instantiate_gemm_bias_helper(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, aname, mn_aligned, kname, k_aligned) \
instantiate_gemm(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, aname, mn_aligned, kname, k_aligned, add, TransformAdd) \
instantiate_gemm(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, aname, mn_aligned, kname, k_aligned, axpby, TransformAxpby)
#define instantiate_gemm_aligned_helper(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn) \
instantiate_gemm_bias_helper(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, taligned, true, taligned, true) \
instantiate_gemm_bias_helper(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, taligned, true, naligned, false) \
instantiate_gemm_bias_helper(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, naligned, false, taligned, true) \
instantiate_gemm_bias_helper(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, naligned, false, naligned, false)
#define instantiate_gemm_transpose_helper(iname, itype, oname, otype, bm, bn, bk, wm, wn) \
instantiate_gemm_aligned_helper(nn, false, false, iname, itype, oname, otype, bm, bn, bk, wm, wn) \
instantiate_gemm_aligned_helper(nt, false, true , iname, itype, oname, otype, bm, bn, bk, wm, wn) \
instantiate_gemm_aligned_helper(tn, true , false, iname, itype, oname, otype, bm, bn, bk, wm, wn) \
instantiate_gemm_aligned_helper(tt, true , true , iname, itype, oname, otype, bm, bn, bk, wm, wn)
#define instantiate_gemm_shapes_helper(iname, itype, oname, otype) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 32, 32, 16, 2, 2) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 64, 64, 16, 2, 2) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 64, 32, 32, 2, 2) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 64, 32, 16, 2, 2) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 32, 64, 16, 2, 2)
instantiate_gemm_shapes_helper(float16, half, float16, half);
instantiate_gemm_shapes_helper(bfloat16, bfloat16_t, bfloat16, bfloat16_t);
instantiate_gemm_shapes_helper(float32, float, float32, float);

280
mlx/backend/metal/kernels/steel/gemm/kernels/steel_gemm_splitk.metal Normal file
View File

@@ -0,0 +1,280 @@
// Copyright © 2024 Apple Inc.
#include "mlx/backend/metal/kernels/bf16.h"
#include "mlx/backend/metal/kernels/steel/gemm/gemm.h"
using namespace metal;
using namespace mlx::steel;
///////////////////////////////////////////////////////////////////////////////
// GEMM kernels
///////////////////////////////////////////////////////////////////////////////
template <typename T,
typename U,
int BM,
int BN,
int BK,
int WM,
int WN,
bool transpose_a,
bool transpose_b,
bool MN_aligned,
bool K_aligned>
[[kernel, max_total_threads_per_threadgroup(WM * WN * 32)]] void gemm_splitk(
const device T *A [[buffer(0)]],
const device T *B [[buffer(1)]],
device U *C [[buffer(2)]],
const constant GEMMSpiltKParams* params [[buffer(3)]],
uint simd_lane_id [[thread_index_in_simdgroup]],
uint simd_group_id [[simdgroup_index_in_threadgroup]],
uint3 tid [[threadgroup_position_in_grid]],
uint3 lid [[thread_position_in_threadgroup]]) {
(void)lid;
using gemm_kernel = GEMMKernel<T, U, BM, BN, BK, WM, WN, transpose_a, transpose_b, MN_aligned, K_aligned>;
using loader_a_t = typename gemm_kernel::loader_a_t;
using loader_b_t = typename gemm_kernel::loader_b_t;
using mma_t = typename gemm_kernel::mma_t;
threadgroup T As[gemm_kernel::tgp_mem_size_a];
threadgroup T Bs[gemm_kernel::tgp_mem_size_b];
const int tid_x = tid.x;
const int tid_y = tid.y;
const int tid_z = tid.z;
if (params->tiles_n <= tid_x || params->tiles_m <= tid_y) {
return;
}
// Find block in A, B, C
const int c_row = tid_y * BM;
const int c_col = tid_x * BN;
const int k_start = params->split_k_partition_size * tid_z;
A += transpose_a ? (c_row + k_start * params->lda) : (k_start + c_row * params->lda);
B += transpose_b ? (k_start + c_col * params->ldb) : (c_col + k_start * params->ldb);
C += (params->split_k_partition_stride * tid_z) + (c_row * params->ldc + c_col);
// Prepare threadgroup loading operations
thread loader_a_t loader_a(A, params->lda, As, simd_group_id, simd_lane_id);
thread loader_b_t loader_b(B, params->ldb, Bs, simd_group_id, simd_lane_id);
// Prepare threadgroup mma operation
thread mma_t mma_op(simd_group_id, simd_lane_id);
int gemm_k_iterations = params->gemm_k_iterations_aligned;
short tgp_bm = min(BM, params->M - c_row);
short tgp_bn = min(BN, params->N - c_col);
short leftover_bk = params->K % BK;
if(MN_aligned || (tgp_bm == BM && tgp_bn == BN)) {
gemm_kernel::gemm_loop(
As,
Bs,
gemm_k_iterations,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk,
LoopAlignment<true, true, true>{});
} else if (tgp_bn == BN) {
gemm_kernel::gemm_loop(
As,
Bs,
gemm_k_iterations,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk,
LoopAlignment<false, true, true>{});
} else if (tgp_bm == BM) {
gemm_kernel::gemm_loop(
As,
Bs,
gemm_k_iterations,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk,
LoopAlignment<true, false, true>{});
} else {
gemm_kernel::gemm_loop(
As,
Bs,
gemm_k_iterations,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk,
LoopAlignment<false, false, true>{});
}
threadgroup_barrier(mem_flags::mem_threadgroup);
if ((tid_z + 1) == (params->split_k_partitions)) {
int gemm_k_iter_remaining = (params->K - (k_start + params->split_k_partition_size)) / BK;
if(!K_aligned || gemm_k_iter_remaining > 0)
gemm_kernel::gemm_loop(
As,
Bs,
gemm_k_iter_remaining,
loader_a,
loader_b,
mma_op,
tgp_bm,
tgp_bn,
leftover_bk,
LoopAlignment<false, false, K_aligned>{});
}
if(MN_aligned || (tgp_bm == BM && tgp_bn == BN)) {
mma_op.store_result(C, params->ldc);
} else {
mma_op.store_result_safe(C, params->ldc, short2(tgp_bn, tgp_bm));
}
}
///////////////////////////////////////////////////////////////////////////////
// GEMM kernel initializations
///////////////////////////////////////////////////////////////////////////////
#define instantiate_gemm(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, aname, mn_aligned, kname, k_aligned) \
template [[host_name("steel_gemm_splitk_" #tname "_" #iname "_" #oname "_bm" #bm "_bn" #bn "_bk" #bk "_wm" #wm "_wn" #wn "_MN_" #aname "_K_" #kname)]] \
[[kernel]] void gemm_splitk<itype, otype, bm, bn, bk, wm, wn, trans_a, trans_b, mn_aligned, k_aligned>( \
const device itype *A [[buffer(0)]], \
const device itype *B [[buffer(1)]], \
device otype *C [[buffer(2)]], \
const constant GEMMSpiltKParams* params [[buffer(3)]], \
uint simd_lane_id [[thread_index_in_simdgroup]], \
uint simd_group_id [[simdgroup_index_in_threadgroup]], \
uint3 tid [[threadgroup_position_in_grid]], \
uint3 lid [[thread_position_in_threadgroup]]);
#define instantiate_gemm_aligned_helper(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn) \
instantiate_gemm(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, taligned, true, taligned, true) \
instantiate_gemm(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, taligned, true, naligned, false) \
instantiate_gemm(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, naligned, false, taligned, true) \
instantiate_gemm(tname, trans_a, trans_b, iname, itype, oname, otype, bm, bn, bk, wm, wn, naligned, false, naligned, false)
#define instantiate_gemm_transpose_helper(iname, itype, oname, otype, bm, bn, bk, wm, wn) \
instantiate_gemm_aligned_helper(nn, false, false, iname, itype, oname, otype, bm, bn, bk, wm, wn) \
instantiate_gemm_aligned_helper(nt, false, true , iname, itype, oname, otype, bm, bn, bk, wm, wn) \
instantiate_gemm_aligned_helper(tn, true , false, iname, itype, oname, otype, bm, bn, bk, wm, wn) \
instantiate_gemm_aligned_helper(tt, true , true , iname, itype, oname, otype, bm, bn, bk, wm, wn)
#define instantiate_gemm_shapes_helper(iname, itype, oname, otype) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 16, 16, 16, 2, 2) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 16, 32, 16, 2, 2) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 32, 16, 16, 2, 2) \
instantiate_gemm_transpose_helper(iname, itype, oname, otype, 32, 32, 16, 2, 2)
instantiate_gemm_shapes_helper(float16, half, float32, float);
instantiate_gemm_shapes_helper(bfloat16, bfloat16_t, float32, float);
instantiate_gemm_shapes_helper(float32, float, float32, float);
///////////////////////////////////////////////////////////////////////////////
// Split k accumulation kernel
///////////////////////////////////////////////////////////////////////////////
template <typename AccT,
typename OutT,
typename Epilogue = TransformNone<OutT, AccT>>
[[kernel]] void gemm_splitk_accum(
const device AccT *C_split [[buffer(0)]],
device OutT *D [[buffer(1)]],
const constant int& k_partitions [[buffer(2)]],
const constant int& partition_stride [[buffer(3)]],
const constant int& ldd [[buffer(4)]],
uint2 gid [[thread_position_in_grid]]) {
// Ajust D and C
D += gid.x + gid.y * ldd;
C_split += gid.x + gid.y * ldd;
int offset = 0;
AccT out = 0;
for(int i = 0; i < k_partitions; i++) {
out += C_split[offset];
offset += partition_stride;
}
// Write output
D[0] = Epilogue::apply(out);
}
template <typename AccT,
typename OutT,
typename Epilogue = TransformAxpby<OutT, AccT>>
[[kernel]] void gemm_splitk_accum_axpby(
const device AccT *C_split [[buffer(0)]],
device OutT *D [[buffer(1)]],
const constant int& k_partitions [[buffer(2)]],
const constant int& partition_stride [[buffer(3)]],
const constant int& ldd [[buffer(4)]],
const device OutT *C [[buffer(5)]],
const constant int& ldc [[buffer(6)]],
const constant int& fdc [[buffer(7)]],
const constant float& alpha [[buffer(8)]],
const constant float& beta [[buffer(9)]],
uint2 gid [[thread_position_in_grid]]) {
// Ajust D and C
C += gid.x * fdc + gid.y * ldc;
D += gid.x + gid.y * ldd;
C_split += gid.x + gid.y * ldd;
int offset = 0;
AccT out = 0;
for(int i = 0; i < k_partitions; i++) {
out += C_split[offset];
offset += partition_stride;
}
// Write output
Epilogue op(alpha, beta);
D[0] = op.apply(out, *C);
}
#define instantiate_accum(oname, otype, aname, atype) \
template [[host_name("steel_gemm_splitk_accum_" #oname "_" #aname)]] \
[[kernel]] void gemm_splitk_accum<atype, otype>( \
const device atype *C_split [[buffer(0)]], \
device otype *D [[buffer(1)]], \
const constant int& k_partitions [[buffer(2)]], \
const constant int& partition_stride [[buffer(3)]], \
const constant int& ldd [[buffer(4)]], \
uint2 gid [[thread_position_in_grid]]); \
template [[host_name("steel_gemm_splitk_accum_" #oname "_" #aname "_axpby")]] \
[[kernel]] void gemm_splitk_accum_axpby<atype, otype>( \
const device atype *C_split [[buffer(0)]], \
device otype *D [[buffer(1)]], \
const constant int& k_partitions [[buffer(2)]], \
const constant int& partition_stride [[buffer(3)]], \
const constant int& ldd [[buffer(4)]], \
const device otype *C [[buffer(5)]], \
const constant int& ldc [[buffer(6)]], \
const constant int& fdc [[buffer(7)]], \
const constant float& alpha [[buffer(8)]], \
const constant float& beta [[buffer(9)]], \
uint2 gid [[thread_position_in_grid]]);
instantiate_accum(bfloat16, bfloat16_t, float32, float);
instantiate_accum(float16, half, float32, float);
instantiate_accum(float32, float, float32, float);

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// Copyright © 2024 Apple Inc.
#pragma once
#include "mlx/backend/metal/kernels/steel/utils.h"
///////////////////////////////////////////////////////////////////////////////
// Loading helper
///////////////////////////////////////////////////////////////////////////////
namespace mlx {
namespace steel {
template <
typename T,
short BROWS,
short BCOLS,
short dst_ld,
short reduction_dim,
short tgp_size,
short alignment = 1,
short n_reads = (BCOLS * BROWS) / (tgp_size),
short TCOLS = BCOLS / n_reads,
short TROWS = tgp_size / TCOLS>
struct BlockLoader {
STEEL_CONST short n_rows = (BROWS + TROWS - 1) / TROWS;
STEEL_CONST short vec_size = n_reads;
// Leading dimension for src
const int src_ld;
const int tile_stride;
// Thread location indices
const short thread_idx;
const short bi;
const short bj;
// threadgroup and device memory
threadgroup T* dst;
const device T* src;
struct alignas(alignment * sizeof(T)) ReadVector {
uint8_t v[sizeof(T) * vec_size];
};
/* Constructor */
METAL_FUNC BlockLoader(
const device T* src_,
const int src_ld_,
threadgroup T* dst_,
ushort simd_group_id [[simdgroup_index_in_threadgroup]],
ushort simd_lane_id [[thread_index_in_simdgroup]])
: src_ld(src_ld_),
tile_stride(reduction_dim ? BCOLS : BROWS * src_ld),
thread_idx(simd_group_id * 32 + simd_lane_id),
bi(thread_idx / TCOLS),
bj(vec_size * (thread_idx % TCOLS)),
dst(dst_ + bi * dst_ld + bj),
src(src_ + bi * src_ld + bj) {}
/* Load from device memory into threadgroup memory - without bound checking */
METAL_FUNC void load_unsafe() const {
STEEL_PRAGMA_UNROLL
for (short i = 0; i < BROWS; i += TROWS) {
*((threadgroup ReadVector*)(&dst[i * dst_ld])) =
*((const device ReadVector*)(&src[i * src_ld]));
}
}
/* Load from device memory into threadgroup memory - without bound checking */
METAL_FUNC void set_mask(
thread const short2& src_tile_dims,
thread bool mask[n_rows][vec_size]) {
STEEL_PRAGMA_UNROLL
for (short i = 0; i < n_rows; i++) {
STEEL_PRAGMA_UNROLL
for (short j = 0; j < vec_size; j++) {
mask[i][j] =
((bi + i) < src_tile_dims.y) && ((bj + j) < src_tile_dims.x);
}
}
}
/* Load from device memory into threadgroup memory - with bound checking */
METAL_FUNC void load_safe(short2 src_tile_dim) const {
src_tile_dim = src_tile_dim - short2(bj, bi);
// Use fast thread memory for bound checks
bool tmp_idx[vec_size];
T tmp_val[vec_size];
STEEL_PRAGMA_UNROLL
for (short i = 0; i < BROWS; i += TROWS) {
// Make sure tmp_idx only contains valid indices
STEEL_PRAGMA_UNROLL
for (short j = 0; j < vec_size; j++) {
tmp_idx[j] = (i < src_tile_dim.y) && (j < src_tile_dim.x);
}
// Read valid indices into tmp_val
STEEL_PRAGMA_UNROLL
for (short j = 0; j < vec_size; j++) {
tmp_val[j] = src[(tmp_idx[j] ? i * src_ld + j : 0)];
}
// Zero out uneeded values
STEEL_PRAGMA_UNROLL
for (short j = 0; j < vec_size; j++) {
tmp_val[j] = tmp_idx[j] ? tmp_val[j] : T(0);
}
// Copy values to threadgroup memory
STEEL_PRAGMA_UNROLL
for (short j = 0; j < vec_size; j++) {
dst[i * dst_ld + j] = tmp_val[j];
}
}
}
/* Load from device memory into threadgroup memory - with bound checking */
METAL_FUNC void load_safe(const thread bool mask[n_rows][vec_size]) const {
T tmp_val[vec_size];
STEEL_PRAGMA_UNROLL
for (short i = 0, ii = 0; i < BROWS; i += TROWS, ii++) {
simdgroup_barrier(mem_flags::mem_none);
// Use fast thread memory for bound checks
// Read valid indices into tmp_val
STEEL_PRAGMA_UNROLL
for (short j = 0; j < vec_size; j++) {
tmp_val[j] = src[(mask[ii][j] ? i * src_ld + j : 0)];
}
simdgroup_barrier(mem_flags::mem_none);
// Zero out uneeded values
STEEL_PRAGMA_UNROLL
for (short j = 0; j < vec_size; j++) {
tmp_val[j] = mask[ii][j] ? tmp_val[j] : T(0);
}
simdgroup_barrier(mem_flags::mem_none);
// Copy values to threadgroup memory
STEEL_PRAGMA_UNROLL
for (short j = 0; j < vec_size; j++) {
dst[i * dst_ld + j] = tmp_val[j];
}
}
}
/* Iteration helper */
METAL_FUNC void next() {
src += tile_stride;
}
};
} // namespace steel
} // namespace mlx

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// Copyright © 2024 Apple Inc.
#pragma once
#include "mlx/backend/metal/kernels/steel/gemm/transforms.h"
#include "mlx/backend/metal/kernels/steel/utils.h"
///////////////////////////////////////////////////////////////////////////////
// MMA helper
///////////////////////////////////////////////////////////////////////////////
namespace mlx {
namespace steel {
template <
typename T,
typename U,
int BM,
int BN,
int BK,
int WM,
int WN,
bool transpose_a,
bool transpose_b,
short lda_tgp,
short ldb_tgp,
typename AccumType = float,
typename Epilogue = TransformNone<U, AccumType>>
struct BlockMMA {
// Warp tile simdgroup matrix strides along M
STEEL_CONST short TM_stride = 8 * WM;
// Warp tile simdgroup matrix strides along M
STEEL_CONST short TN_stride = 8 * WN;
// Warp tile size along M
STEEL_CONST short TM = BM / TM_stride;
// Warp tile size along N
STEEL_CONST short TN = BN / TN_stride;
// Strides of A, B along reduction axis
STEEL_CONST short simd_stride_a = {
transpose_a ? TM_stride : TM_stride * lda_tgp};
STEEL_CONST short simd_stride_b = {
transpose_b ? TN_stride * ldb_tgp : TN_stride};
// Jump between elements
STEEL_CONST short jump_a = {transpose_a ? lda_tgp : 1};
STEEL_CONST short jump_b = {transpose_b ? ldb_tgp : 1};
STEEL_CONST short tile_stride_a = {transpose_a ? 8 * lda_tgp : 8};
STEEL_CONST short tile_stride_b = {transpose_b ? 8 : 8 * ldb_tgp};
// Simdgroup matrices
simdgroup_matrix<AccumType, 8, 8> Asimd[TM];
simdgroup_matrix<AccumType, 8, 8> Bsimd[TN];
simdgroup_matrix<AccumType, 8, 8> results[TM * TN] = {
simdgroup_matrix<AccumType, 8, 8>(0)};
// Offsets within threadgroup
const short tm;
const short tn;
short sm;
short sn;
short As_offset;
short Bs_offset;
/* Constructor */
METAL_FUNC BlockMMA(
ushort simd_group_id [[simdgroup_index_in_threadgroup]],
ushort simd_lane_id [[thread_index_in_simdgroup]])
: tm(8 * (simd_group_id / WN)), tn(8 * (simd_group_id % WN)) {
// Determine thread position in simdgroup matrix
short qid = simd_lane_id / 4;
sm = (qid & 4) + (simd_lane_id / 2) % 4;
sn = (qid & 2) * 2 + (simd_lane_id % 2) * 2;
// Determine thread and simdgroup offset
As_offset =
transpose_a ? ((sn)*lda_tgp + (tm + sm)) : ((sn) + (tm + sm) * lda_tgp);
Bs_offset =
transpose_b ? ((tn + sn) * ldb_tgp + (sm)) : ((sm)*ldb_tgp + (tn + sn));
}
/* (BM, BK) X (BK, BN) multiply accumulate function */
METAL_FUNC void mma(const threadgroup T* As, const threadgroup T* Bs) {
// Adjust for simdgroup and thread location
As += As_offset;
Bs += Bs_offset;
// Iterate over BK in blocks of 8
STEEL_PRAGMA_UNROLL
for (short kk = 0; kk < BK; kk += 8) {
simdgroup_barrier(mem_flags::mem_none);
// Load elements from threadgroup A as simdgroup matrices
STEEL_PRAGMA_UNROLL
for (short i = 0; i < TM; i++) {
Asimd[i].thread_elements()[0] =
static_cast<AccumType>(As[i * simd_stride_a + 0]);
Asimd[i].thread_elements()[1] =
static_cast<AccumType>(As[i * simd_stride_a + jump_a]);
}
simdgroup_barrier(mem_flags::mem_none);
// Load elements from threadgroup B as simdgroup matrices
STEEL_PRAGMA_UNROLL
for (short j = 0; j < TN; j++) {
Bsimd[j].thread_elements()[0] =
static_cast<AccumType>(Bs[j * simd_stride_b + 0]);
Bsimd[j].thread_elements()[1] =
static_cast<AccumType>(Bs[j * simd_stride_b + jump_b]);
}
simdgroup_barrier(mem_flags::mem_none);
// Multiply and accumulate into result simdgroup matrices
STEEL_PRAGMA_UNROLL
for (short i = 0; i < TM; i++) {
STEEL_PRAGMA_UNROLL
for (short j = 0; j < TN; j++) {
short j_serp = (i % 2) ? (TN - 1 - j) : j;
simdgroup_multiply_accumulate(
results[i * TN + j_serp],
Asimd[i],
Bsimd[j_serp],
results[i * TN + j_serp]);
}
}
// Progress to next simdgroup tile
As += tile_stride_a;
Bs += tile_stride_b;
}
}
/* Store results from simdgroup_matrix results into device memory */
METAL_FUNC void store_result(device U* C, const int ldc) const {
// Adjust for simdgroup and thread location
C += (sm + tm) * ldc + tn + sn;
// Loop over all simdgroup tiles
STEEL_PRAGMA_UNROLL
for (short i = 0; i < TM; i++) {
STEEL_PRAGMA_UNROLL
for (short j = 0; j < TN; j++) {
// Get accumulated result and associated offset in C
thread const auto& accum = results[i * TN + j].thread_elements();
int offset = (i * TM_stride) * ldc + (j * TN_stride);
// Apply epilogue
U outs[2] = {Epilogue::apply(accum[0]), Epilogue::apply(accum[1])};
// Write out C
C[offset] = outs[0];
C[offset + 1] = outs[1];
}
}
}
METAL_FUNC void
store_result_safe(device U* C, const int ldc, short2 dst_tile_dims) const {
// Adjust for simdgroup and thread location
C += (sm + tm) * ldc + (tn + sn);
dst_tile_dims -= short2(tn + sn, sm + tm);
STEEL_PRAGMA_UNROLL
for (int i = 0; i < TM; i++) {
if (i * TM_stride < dst_tile_dims.y) {
STEEL_PRAGMA_UNROLL
for (int j = 0; j < TN; j++) {
// Get accumulated result and associated offset in C
thread const auto& accum = results[i * TN + j].thread_elements();
int offset = (i * TM_stride) * ldc + (j * TN_stride);
// Apply epilogue and output C
if (j * TN_stride < dst_tile_dims.x) {
C[offset] = Epilogue::apply(accum[0]);
}
if (j * TN_stride + 1 < dst_tile_dims.x) {
C[offset + 1] = Epilogue::apply(accum[1]);
}
}
}
}
}
/* Store results from simdgroup_matrix results into device memory */
METAL_FUNC void store_result(
device U* D,
const int ldd,
const device U* C,
const int ldc,
const int fdc,
thread const Epilogue& epilogue_op) const {
// Adjust for simdgroup and thread location
C += (sm + tm) * ldc + (tn + sn) * fdc;
D += (sm + tm) * ldd + tn + sn;
// Loop over all simdgroup tiles
STEEL_PRAGMA_UNROLL
for (short i = 0; i < TM; i++) {
STEEL_PRAGMA_UNROLL
for (short j = 0; j < TN; j++) {
// Get accumulated result and associated offset in C
thread const auto& accum = results[i * TN + j].thread_elements();
int offset_c = (i * TM_stride) * ldc + (j * TN_stride) * fdc;
int offset_d = (i * TM_stride) * ldd + (j * TN_stride);
// Apply epilogue
U outs[2] = {
epilogue_op.apply(accum[0], C[offset_c]),
epilogue_op.apply(accum[1], C[offset_c + fdc])};
// Write out D
D[offset_d] = outs[0];
D[offset_d + 1] = outs[1];
}
}
}
METAL_FUNC void store_result_safe(
device U* D,
const int ldd,
const device U* C,
const int ldc,
const int fdc,
short2 dst_tile_dims,
thread const Epilogue& epilogue_op) const {
// Adjust for simdgroup and thread location
C += (sm + tm) * ldc + (tn + sn) * fdc;
D += (sm + tm) * ldd + tn + sn;
dst_tile_dims -= short2(tn + sn, sm + tm);
STEEL_PRAGMA_UNROLL
for (int i = 0; i < TM; i++) {
if (i * TM_stride < dst_tile_dims.y) {
STEEL_PRAGMA_UNROLL
for (int j = 0; j < TN; j++) {
// Get accumulated result and associated offset in C
thread const auto& accum = results[i * TN + j].thread_elements();
int offset_c = (i * TM_stride) * ldc + (j * TN_stride) * fdc;
int offset_d = (i * TM_stride) * ldd + (j * TN_stride);
// Apply epilogue and output C
if (j * TN_stride < dst_tile_dims.x) {
D[offset_d] = epilogue_op.apply(accum[0], C[offset_c]);
}
if (j * TN_stride + 1 < dst_tile_dims.x) {
D[offset_d + 1] = epilogue_op.apply(accum[1], C[offset_c + fdc]);
}
}
}
}
}
};
} // namespace steel
} // namespace mlx

79
mlx/backend/metal/kernels/steel/gemm/params.h Normal file
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@@ -0,0 +1,79 @@
// Copyright © 2024 Apple Inc.
#pragma once
///////////////////////////////////////////////////////////////////////////////
// GEMM param classes
///////////////////////////////////////////////////////////////////////////////
namespace mlx {
namespace steel {
struct GEMMParams {
const int M;
const int N;
const int K;
const int lda;
const int ldb;
const int ldc;
const int tiles_n;
const int tiles_m;
const int batch_stride_a;
const int batch_stride_b;
const int batch_stride_c;
const int swizzle_log;
const int gemm_k_iterations_aligned;
};
struct GEMMSpiltKParams {
const int M;
const int N;
const int K;
const int lda;
const int ldb;
const int ldc;
const int tiles_n;
const int tiles_m;
const int split_k_partitions;
const int split_k_partition_stride;
const int split_k_partition_size;
const int gemm_k_iterations_aligned;
};
struct GEMMAddMMParams {
const int M;
const int N;
const int K;
const int lda;
const int ldb;
const int ldc;
const int ldd;
const int tiles_n;
const int tiles_m;
const int batch_stride_a;
const int batch_stride_b;
const int batch_stride_c;
const int batch_stride_d;
const int swizzle_log;
const int gemm_k_iterations_aligned;
const float alpha;
const float beta;
const int fdc;
};
} // namespace steel
} // namespace mlx

63
mlx/backend/metal/kernels/steel/gemm/transforms.h Normal file
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@@ -0,0 +1,63 @@
// Copyright © 2024 Apple Inc.
#pragma once
#include "mlx/backend/metal/kernels/steel/utils.h"
///////////////////////////////////////////////////////////////////////////////
// Transforms and Epilogues
///////////////////////////////////////////////////////////////////////////////
namespace mlx {
namespace steel {
template <typename OutT, typename InT>
struct TransformNone {
static METAL_FUNC OutT apply(InT x) {
return static_cast<OutT>(x);
}
static METAL_FUNC OutT apply(InT x, OutT) {
return static_cast<OutT>(x);
}
};
template <typename OutT, typename InT>
struct TransformAdd {
TransformAdd(const float, const float) {}
static METAL_FUNC OutT apply(InT x, OutT c) {
return static_cast<OutT>(x) + c;
}
};
template <typename OutT, typename InT>
struct TransformAxpby {
const float alpha;
const float beta;
TransformAxpby(const float alpha_, const float beta_)
: alpha(alpha_), beta(beta_) {}
METAL_FUNC OutT apply(InT x, OutT c) const {
return static_cast<OutT>(x * alpha + (beta * c));
}
};
template <typename T>
struct AccumHelper {
typedef float accum_type;
};
struct BlockSwizzle {
static METAL_FUNC int2
swizzle(uint3 tid [[threadgroup_position_in_grid]], const int swizzle_log) {
const int tid_x = (tid.x) >> swizzle_log;
const int tid_y =
((tid.y) << swizzle_log) + ((tid.x) & ((1 << swizzle_log) - 1));
return int2(tid_x, tid_y);
}
};
} // namespace steel
} // namespace mlx

5
mlx/backend/metal/kernels/steel/host.h Normal file
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@@ -0,0 +1,5 @@
// Copyright © 2024 Apple Inc.
#pragma once
#include "mlx/backend/metal/kernels/steel/gemm/params.h"

9
mlx/backend/metal/kernels/steel/utils.h Normal file
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@@ -0,0 +1,9 @@
// Copyright © 2024 Apple Inc.
#pragma once
#include <metal_stdlib>
#include "mlx/backend/metal/kernels/steel/host.h"
#define STEEL_CONST static constant constexpr const
#define STEEL_PRAGMA_UNROLL _Pragma("clang loop unroll(full)")

471
mlx/backend/metal/matmul.cpp
View File

@@ -8,6 +8,7 @@
#include "mlx/backend/metal/copy.h"
#include "mlx/backend/metal/device.h"
#include "mlx/backend/metal/kernels/defines.h"
#include "mlx/backend/metal/kernels/steel/host.h"
#include "mlx/backend/metal/matmul.h"
#include "mlx/backend/metal/mps/gemm.h"
#include "mlx/backend/metal/utils.h"
@@ -16,6 +17,10 @@
namespace mlx::core {
///////////////////////////////////////////////////////////////////////////////
// MPS Matmul fallback
///////////////////////////////////////////////////////////////////////////////
namespace {
bool use_mps() {
@@ -46,7 +51,9 @@ inline void mps_matmul(
int ldb,
bool transpose_a,
bool transpose_b,
std::vector<array>& copies) {
std::vector<array>& copies,
float alpha = 1.0f,
float beta = 0.0f) {
MPS::DataType mps_dtype = MPS::DataTypeFloat32;
if (out.dtype() == float16) {
@@ -121,7 +128,7 @@ inline void mps_matmul(
auto out_mat = MPS::Matrix::alloc()->init(out_buf, out_desc);
auto kernel = MPS::MatrixMultiplication::alloc()->init(
d.mtl_device(), transpose_a, transpose_b, M, N, K, 1.0, 0.0);
d.mtl_device(), transpose_a, transpose_b, M, N, K, alpha, beta);
auto command_buffer = d.get_command_buffer(s.index);
kernel->setBatchSize(batch_size_out);
@@ -162,7 +169,7 @@ inline void mps_matmul(
auto out_mat = MPS::Matrix::alloc()->init(out_buf, out_desc);
auto kernel = MPS::MatrixMultiplication::alloc()->init(
d.mtl_device(), transpose_a, transpose_b, M, N, K, 1.0, 0.0);
d.mtl_device(), transpose_a, transpose_b, M, N, K, alpha, beta);
auto command_buffer = d.get_command_buffer(s.index);
for (int i = 0; i < batch_size_out; ++i) {
@@ -186,7 +193,11 @@ inline void mps_matmul(
} // namespace
void mlx_matmul(
///////////////////////////////////////////////////////////////////////////////
// Steel matmul fallback
///////////////////////////////////////////////////////////////////////////////
void steel_matmul(
const Stream& s,
metal::Device& d,
const array& a,
@@ -201,6 +212,15 @@ void mlx_matmul(
bool transpose_a,
bool transpose_b,
std::vector<array>& copies) {
using namespace mlx::steel;
// Coalesce (B, M, K) X (K, N) to (B*M, K) X (K, N)
if (batch_size_out > 1 && !transpose_a &&
a.data_size() == batch_size_out * M * K && b.size() == K * N) {
M = M * batch_size_out;
batch_size_out = 1;
}
// Account for batch sizes and basic broadcasting
int batch_size_a = a.data_size() / (M * K);
int batch_size_b = b.data_size() / (K * N);
@@ -209,11 +229,108 @@ void mlx_matmul(
int matrix_stride_b = (batch_size_b == 1) ? 0 : K * N;
int matrix_stride_out = M * N;
/////////////////////////////////////////////////////////////////////////////
// Split K specialization
int _tm = M / 16;
int _tn = N / 16;
int _tk = K / 16;
if (batch_size_out == 1 && (_tm * _tn) <= 32 && _tk >= 8) {
int bm = M < 40 ? 16 : 32;
int bn = N < 40 ? 16 : 32;
int bk = 16;
int wm = 2, wn = 2;
int split_k_partitions =
_tk < 16 ? 2 : (_tk < 32 ? 4 : (_tk < 64 ? 8 : 16));
int split_k_partition_stride = M * N;
int gemm_k_iterations = (K / bk) / split_k_partitions;
int split_k_partition_size = gemm_k_iterations * bk;
array C_split({split_k_partitions, M, N}, float32, nullptr, {});
C_split.set_data(allocator::malloc_or_wait(C_split.nbytes()));
copies.push_back(C_split);
std::ostringstream kname;
kname << "steel_gemm_splitk_" << (transpose_a ? 't' : 'n')
<< (transpose_b ? 't' : 'n') << "_" << type_to_name(a) << "_"
<< type_to_name(C_split) << "_bm" << bm << "_bn" << bn << "_bk" << bk
<< "_wm" << wm << "_wn" << wn << "_MN_"
<< ((M % bm == 0 && N % bn == 0) ? "t" : "n") << "aligned"
<< "_K_" << ((K % bk == 0) ? "t" : "n") << "aligned";
// Encode and dispatch gemm kernel
auto compute_encoder = d.get_command_encoder(s.index);
auto kernel = d.get_kernel(kname.str());
compute_encoder->setComputePipelineState(kernel);
int tn = (N + bn - 1) / bn;
int tm = (M + bm - 1) / bm;
GEMMSpiltKParams params{
M,
N,
K,
lda,
ldb,
N,
tn,
tm,
split_k_partitions,
split_k_partition_stride,
split_k_partition_size,
gemm_k_iterations};
MTL::Size group_dims = MTL::Size(32, wn, wm);
MTL::Size grid_dims = MTL::Size(tn, tm, split_k_partitions);
set_array_buffer(compute_encoder, a, 0);
set_array_buffer(compute_encoder, b, 1);
set_array_buffer(compute_encoder, C_split, 2);
compute_encoder->setBytes(&params, sizeof(GEMMSpiltKParams), 3);
compute_encoder->dispatchThreadgroups(grid_dims, group_dims);
// Do accum kernel
{
auto c_split_buf =
static_cast<const MTL::Resource*>(C_split.buffer().ptr());
const class MTL::Resource* const resources[1] = {c_split_buf};
compute_encoder->memoryBarrier(resources, 1);
auto kernel = d.get_kernel(
"steel_gemm_splitk_accum_" + type_to_name(out) + "_" +
type_to_name(C_split));
compute_encoder->setComputePipelineState(kernel);
// Set the arguments for the kernel
set_array_buffer(compute_encoder, C_split, 0);
set_array_buffer(compute_encoder, out, 1);
compute_encoder->setBytes(&split_k_partitions, sizeof(int), 2);
compute_encoder->setBytes(&split_k_partition_stride, sizeof(int), 3);
compute_encoder->setBytes(&N, sizeof(int), 4);
// Launch enough thread groups for each output
MTL::Size grid_dims = MTL::Size(N, M, 1);
MTL::Size group_dims = MTL::Size(std::min(1024, N * M), 1, 1);
compute_encoder->dispatchThreads(grid_dims, group_dims);
}
d.get_command_buffer(s.index)->addCompletedHandler(
[copies](MTL::CommandBuffer*) mutable { copies.clear(); });
return;
}
/////////////////////////////////////////////////////////////////////////////
// Regular kernel dispatch
// Determine dispatch kernel
int bm = 32, bn = 32, bk = 16;
int wm = 2, wn = 2;
if ((size_t)batch_size_out * M * N >= 2ul << 20) {
if ((size_t)batch_size_out * M * N >= 1ul << 20) {
if (!transpose_a && transpose_b) {
bm = 64;
bn = (out.dtype() == float32) ? 64 : 32;
@@ -224,10 +341,12 @@ void mlx_matmul(
}
}
// Prepare kernel name
std::ostringstream kname;
kname << "gemm_" << (transpose_a ? 't' : 'n') << (transpose_b ? 't' : 'n')
<< "_" << type_to_name(a) << "_" << type_to_name(out) << "_bm" << bm
<< "_bn" << bn << "_bk" << bk << "_wm" << wm << "_wn" << wn << "_MN_"
kname << "steel_gemm_" << (transpose_a ? 't' : 'n')
<< (transpose_b ? 't' : 'n') << "_" << type_to_name(a) << "_"
<< type_to_name(out) << "_bm" << bm << "_bn" << bn << "_bk" << bk
<< "_wm" << wm << "_wn" << wn << "_MN_"
<< ((M % bm == 0 && N % bn == 0) ? "t" : "n") << "aligned"
<< "_K_" << ((K % bk == 0) ? "t" : "n") << "aligned";
@@ -236,34 +355,55 @@ void mlx_matmul(
auto kernel = d.get_kernel(kname.str());
compute_encoder->setComputePipelineState(kernel);
// Use problem size to determine threadblock swizzle
int tn = (N + bn - 1) / bn;
int tm = (M + bm - 1) / bm;
// TODO: Explore device-based tuning for swizzle
int swizzle_log = 0; // tm >= 6 ? 3 : (tm <= 3 ? 0 : 2);
// Prepare steel matmul params
GEMMParams params{
M,
N,
K,
lda,
ldb,
N,
tn,
tm,
matrix_stride_a,
matrix_stride_b,
matrix_stride_out,
swizzle_log,
(K / bk)};
// Prepare launch grid params
int tile = 1 << swizzle_log;
tm = (tm + tile - 1) / tile;
tn = tn * tile;
MTL::Size group_dims = MTL::Size(32, wn, wm);
MTL::Size grid_dims = MTL::Size(tn, tm, batch_size_out);
// Launch only 1 kernel in the case of simple batching / broadcasting
if (batch_size_out == std::max(batch_size_a, batch_size_b) &&
(batch_size_a == batch_size_b ||
std::min(batch_size_a, batch_size_b) == 1)) {
MTL::Size group_dims = MTL::Size(32, wn, wm);
MTL::Size grid_dims =
MTL::Size((N + bn - 1) / bn, (M + bm - 1) / bm, batch_size_out);
set_array_buffer(compute_encoder, a, 0);
set_array_buffer(compute_encoder, b, 1);
set_array_buffer(compute_encoder, out, 2);
compute_encoder->setBytes(&M, sizeof(int), 3);
compute_encoder->setBytes(&N, sizeof(int), 4);
compute_encoder->setBytes(&K, sizeof(int), 5);
compute_encoder->setBytes(&matrix_stride_a, sizeof(int), 6);
compute_encoder->setBytes(&matrix_stride_b, sizeof(int), 7);
compute_encoder->setBytes(&matrix_stride_out, sizeof(int), 8);
compute_encoder->setBytes(&params, sizeof(GEMMParams), 3);
compute_encoder->dispatchThreadgroups(grid_dims, group_dims);
} else { // Other launch kernels with set offsets
} else { // Otherwise launch kernels with set offsets
MTL::Size grid_dims_single = MTL::Size(tn, tm, 1);
for (int i = 0; i < batch_size_out; ++i) {
auto a_off = elem_to_loc(M * K * i, a.shape(), a.strides());
auto b_off = elem_to_loc(K * N * i, b.shape(), b.strides());
MTL::Size group_dims = MTL::Size(32, wn, wm);
MTL::Size grid_dims = MTL::Size((N + bn - 1) / bn, (M + bm - 1) / bm, 1);
auto a_buf = static_cast<const MTL::Buffer*>(a.buffer().ptr());
auto b_buf = static_cast<const MTL::Buffer*>(b.buffer().ptr());
auto out_buf = static_cast<const MTL::Buffer*>(out.buffer().ptr());
@@ -272,13 +412,8 @@ void mlx_matmul(
compute_encoder->setBuffer(b_buf, b_off * b.itemsize(), 1);
compute_encoder->setBuffer(out_buf, i * M * N * out.itemsize(), 2);
compute_encoder->setBytes(&M, sizeof(int), 3);
compute_encoder->setBytes(&N, sizeof(int), 4);
compute_encoder->setBytes(&K, sizeof(int), 5);
compute_encoder->setBytes(&matrix_stride_a, sizeof(int), 6);
compute_encoder->setBytes(&matrix_stride_b, sizeof(int), 7);
compute_encoder->setBytes(&matrix_stride_out, sizeof(int), 8);
compute_encoder->dispatchThreadgroups(grid_dims, group_dims);
compute_encoder->setBytes(&params, sizeof(GEMMParams), 3);
compute_encoder->dispatchThreadgroups(grid_dims_single, group_dims);
}
}
@@ -300,6 +435,9 @@ void Matmul::eval_gpu(const std::vector<array>& inputs, array& out) {
auto& a_pre = inputs[0];
auto& b_pre = inputs[1];
/////////////////////////////////////////////////////////////////////////////
// Init checks and prep
// Keep a vector with copies to be cleared in the completed buffer to release
// the arrays
std::vector<array> copies;
@@ -328,6 +466,9 @@ void Matmul::eval_gpu(const std::vector<array>& inputs, array& out) {
auto batch_size_out = out.size() / (M * N);
/////////////////////////////////////////////////////////////////////////////
// Gemv specialization
// Route to gemv if needed
if (std::min(M, N) == 1) {
// Collect problem info
@@ -433,10 +574,13 @@ void Matmul::eval_gpu(const std::vector<array>& inputs, array& out) {
return;
}
d.end_encoding(s.index);
/////////////////////////////////////////////////////////////////////////////
// Gemm specialization
if (use_mps()) {
mps_matmul(
d.end_encoding(s.index);
return mps_matmul(
s,
d,
a,
@@ -451,10 +595,9 @@ void Matmul::eval_gpu(const std::vector<array>& inputs, array& out) {
a_transposed,
b_transposed,
copies);
return;
}
mlx_matmul(
return steel_matmul(
s,
d,
a,
@@ -471,4 +614,266 @@ void Matmul::eval_gpu(const std::vector<array>& inputs, array& out) {
copies);
}
void AddMM::eval_gpu(const std::vector<array>& inputs, array& out) {
assert(inputs.size() == 2);
if (!is_floating_point(out.dtype())) {
throw std::runtime_error(
"[matmul] Does not yet support non-floating point types.");
}
out.set_data(allocator::malloc_or_wait(out.nbytes()));
auto& s = stream();
auto& d = metal::device(s.device);
auto& a_pre = inputs[0];
auto& b_pre = inputs[1];
auto& c_pre = inputs[2];
/////////////////////////////////////////////////////////////////////////////
// Init checks and prep
// Keep a vector with copies to be cleared in the completed buffer to release
// the arrays
std::vector<array> copies;
auto check_transpose = [&copies, &s](const array& arr) {
auto stx = arr.strides()[arr.ndim() - 2];
auto sty = arr.strides()[arr.ndim() - 1];
if (stx == arr.shape(-1) && sty == 1) {
return std::make_tuple(false, stx, arr);
} else if (stx == 1 && sty == arr.shape(-2)) {
return std::make_tuple(true, sty, arr);
} else {
array arr_copy(arr.shape(), arr.dtype(), nullptr, {});
copy_gpu(arr, arr_copy, CopyType::General, s);
copies.push_back(arr_copy);
size_t stx = arr.shape(-1);
return std::make_tuple(false, stx, arr_copy);
}
};
auto [transpose_a, a_cols, a] = check_transpose(a_pre);
auto [transpose_b, b_cols, b] = check_transpose(b_pre);
int M = a.shape(-2);
int N = b.shape(-1);
int K = a.shape(-1);
auto batch_size_out = out.size() / (M * N);
array c = c_pre;
int ldc = c.strides()[c.ndim() - 2];
int fdc = c.strides()[c.ndim() - 1];
int matrix_stride_c = c.ndim() <= 2 ? 0 : c.strides()[c.ndim() - 3];
int lda = a_cols;
int ldb = b_cols;
using namespace mlx::steel;
// Account for batch sizes and basic broadcasting
int batch_size_a = a.data_size() / (M * K);
int batch_size_b = b.data_size() / (K * N);
int matrix_stride_a = (batch_size_a == 1) ? 0 : M * K;
int matrix_stride_b = (batch_size_b == 1) ? 0 : K * N;
int matrix_stride_out = M * N;
int _tm = M / 16;
int _tn = N / 16;
int _tk = K / 16;
/////////////////////////////////////////////////////////////////////////////
// Split K specialization
if (batch_size_out == 1 && (_tm * _tn) <= 32 && _tk >= 8) {
int bm = M < 40 ? 16 : 32;
int bn = N < 40 ? 16 : 32;
int bk = 16;
int wm = 2, wn = 2;
int split_k_partitions =
_tk < 16 ? 2 : (_tk < 32 ? 4 : (_tk < 64 ? 8 : 16));
int split_k_partition_stride = M * N;
int gemm_k_iterations = (K / bk) / split_k_partitions;
int split_k_partition_size = gemm_k_iterations * bk;
array C_split({split_k_partitions, M, N}, float32, nullptr, {});
C_split.set_data(allocator::malloc_or_wait(C_split.nbytes()));
copies.push_back(C_split);
std::ostringstream kname;
kname << "steel_gemm_splitk_" << (transpose_a ? 't' : 'n')
<< (transpose_b ? 't' : 'n') << "_" << type_to_name(a) << "_"
<< type_to_name(C_split) << "_bm" << bm << "_bn" << bn << "_bk" << bk
<< "_wm" << wm << "_wn" << wn << "_MN_"
<< ((M % bm == 0 && N % bn == 0) ? "t" : "n") << "aligned"
<< "_K_" << ((K % bk == 0) ? "t" : "n") << "aligned";
// Encode and dispatch gemm kernel
auto compute_encoder = d.get_command_encoder(s.index);
auto kernel = d.get_kernel(kname.str());
compute_encoder->setComputePipelineState(kernel);
int tn = (N + bn - 1) / bn;
int tm = (M + bm - 1) / bm;
GEMMSpiltKParams params{
M,
N,
K,
lda,
ldb,
N,
tn,
tm,
split_k_partitions,
split_k_partition_stride,
split_k_partition_size,
gemm_k_iterations};
MTL::Size group_dims = MTL::Size(32, wn, wm);
MTL::Size grid_dims = MTL::Size(tn, tm, split_k_partitions);
set_array_buffer(compute_encoder, a, 0);
set_array_buffer(compute_encoder, b, 1);
set_array_buffer(compute_encoder, C_split, 2);
compute_encoder->setBytes(&params, sizeof(GEMMSpiltKParams), 3);
compute_encoder->dispatchThreadgroups(grid_dims, group_dims);
// Do accum kernel
{
auto kernel = d.get_kernel(
"steel_gemm_splitk_accum_" + type_to_name(out) + "_" +
type_to_name(C_split) + "_axpby");
compute_encoder->setComputePipelineState(kernel);
// Set the arguments for the kernel
set_array_buffer(compute_encoder, C_split, 0);
set_array_buffer(compute_encoder, out, 1);
compute_encoder->setBytes(&split_k_partitions, sizeof(int), 2);
compute_encoder->setBytes(&split_k_partition_stride, sizeof(int), 3);
compute_encoder->setBytes(&N, sizeof(int), 4);
set_array_buffer(compute_encoder, c, 5);
compute_encoder->setBytes(&ldc, sizeof(int), 6);
compute_encoder->setBytes(&fdc, sizeof(int), 7);
compute_encoder->setBytes(&alpha_, sizeof(float), 8);
compute_encoder->setBytes(&beta_, sizeof(float), 9);
// Launch enough thread groups for each output
MTL::Size grid_dims = MTL::Size(N, M, 1);
MTL::Size group_dims = MTL::Size(std::min(1024, N * M), 1, 1);
compute_encoder->dispatchThreads(grid_dims, group_dims);
}
d.get_command_buffer(s.index)->addCompletedHandler(
[copies](MTL::CommandBuffer*) mutable { copies.clear(); });
return;
}
/////////////////////////////////////////////////////////////////////////////
// Regular addmm dispatch
// Determine dispatch kernel
int bm = 32, bn = 32, bk = 16;
int wm = 2, wn = 2;
if ((size_t)batch_size_out * M * N >= 1ul << 20) {
if (!transpose_a && transpose_b) {
bm = 64;
bn = (out.dtype() == float32) ? 64 : 32;
bk = (out.dtype() == float32) ? 16 : 32;
} else {
bm = 64;
bn = 64;
}
}
std::ostringstream kname;
kname << "steel_addmm_" << (transpose_a ? 't' : 'n')
<< (transpose_b ? 't' : 'n') << "_" << type_to_name(a) << "_"
<< type_to_name(out) << "_bm" << bm << "_bn" << bn << "_bk" << bk
<< "_wm" << wm << "_wn" << wn << "_MN_"
<< ((M % bm == 0 && N % bn == 0) ? "t" : "n") << "aligned"
<< "_K_" << ((K % bk == 0) ? "t" : "n") << "aligned"
<< ((alpha_ == 1. && beta_ == 1.) ? "_add" : "_axpby");
// Encode and dispatch kernel
auto compute_encoder = d.get_command_encoder(s.index);
auto kernel = d.get_kernel(kname.str());
compute_encoder->setComputePipelineState(kernel);
int tn = (N + bn - 1) / bn;
int tm = (M + bm - 1) / bm;
// TODO: Explore device-based tuning for swizzle
int swizzle_log = 0; // tm >= 6 ? 3 : (tm <= 3 ? 0 : 2);
GEMMAddMMParams params{
M,
N,
K,
lda,
ldb,
ldc,
N,
tn,
tm,
matrix_stride_a,
matrix_stride_b,
matrix_stride_c,
matrix_stride_out,
swizzle_log,
(K / bk),
alpha_,
beta_,
fdc};
int tile = 1 << swizzle_log;
tm = (tm + tile - 1) / tile;
tn = tn * tile;
MTL::Size group_dims = MTL::Size(32, wn, wm);
MTL::Size grid_dims = MTL::Size(tn, tm, batch_size_out);
// Launch only 1 kernel in the case of simple batching / broadcasting
if (batch_size_out == std::max(batch_size_a, batch_size_b) &&
(batch_size_a == batch_size_b ||
std::min(batch_size_a, batch_size_b) == 1)) {
set_array_buffer(compute_encoder, a, 0);
set_array_buffer(compute_encoder, b, 1);
set_array_buffer(compute_encoder, c, 2);
set_array_buffer(compute_encoder, out, 3);
compute_encoder->setBytes(&params, sizeof(GEMMAddMMParams), 4);
compute_encoder->dispatchThreadgroups(grid_dims, group_dims);
} else { // Otherwise launch kernels with set offsets
MTL::Size grid_dims_single = MTL::Size(tn, tm, 1);
for (int i = 0; i < batch_size_out; ++i) {
auto a_off = elem_to_loc(M * K * i, a.shape(), a.strides());
auto b_off = elem_to_loc(K * N * i, b.shape(), b.strides());
auto c_off = elem_to_loc(M * N * i, c.shape(), c.strides());
auto a_buf = static_cast<const MTL::Buffer*>(a.buffer().ptr());
auto b_buf = static_cast<const MTL::Buffer*>(b.buffer().ptr());
auto c_buf = static_cast<const MTL::Buffer*>(c.buffer().ptr());
auto out_buf = static_cast<const MTL::Buffer*>(out.buffer().ptr());
compute_encoder->setBuffer(a_buf, a_off * a.itemsize(), 0);
compute_encoder->setBuffer(b_buf, b_off * b.itemsize(), 1);
compute_encoder->setBuffer(c_buf, c_off * c.itemsize(), 2);
compute_encoder->setBuffer(out_buf, i * M * N * out.itemsize(), 3);
compute_encoder->setBytes(&params, sizeof(GEMMAddMMParams), 4);
compute_encoder->dispatchThreadgroups(grid_dims_single, group_dims);
}
}
d.get_command_buffer(s.index)->addCompletedHandler(
[copies](MTL::CommandBuffer*) mutable { copies.clear(); });
return;
}
} // namespace mlx::core

2
mlx/backend/metal/matmul.h
View File

@@ -12,7 +12,7 @@
namespace mlx::core {
void mlx_matmul(
void steel_matmul(
const Stream& s,
metal::Device& d,
const array& a,