mirror of
https://github.com/ml-explore/mlx.git
synced 2025-07-23 18:11:17 +08:00
Fix gemv broadcasting bug (#6)
* Fix broadcasting bug in gemv * Add relevant tests in test_blas.py
This commit is contained in:
Jagrit Digani
GitHub
parent
49cda449b1
commit
d518b3b6a5
@ -3,8 +3,9 @@
|
||||
#include <metal_stdlib>
|
||||
#include <metal_simdgroup>
|
||||
|
||||
#include "mlx/backend/metal/kernels/defines.h"
|
||||
#include "mlx/backend/metal/kernels/bf16.h"
|
||||
#include "mlx/backend/metal/kernels/defines.h"
|
||||
#include "mlx/backend/metal/kernels/utils.h"
|
||||
|
||||
using namespace metal;
|
||||
|
||||
@ -12,52 +13,57 @@ using namespace metal;
|
||||
/// Matrix vector multiplication
|
||||
///////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
static constant constexpr int SIMD_SIZE = 32;
|
||||
#define MLX_MTL_CONST static constant constexpr const
|
||||
|
||||
template <typename T,
|
||||
const int BM, /* Threadgroup rows (in threads) */
|
||||
const int BN, /* Threadgroup cols (in threads) */
|
||||
const int TM, /* Thread rows (in elements) */
|
||||
const int TN> /* Thread cols (in elements) */
|
||||
[[kernel]] void gemv(
|
||||
const device T* mat [[buffer(0)]],
|
||||
const device T* in_vec [[buffer(1)]],
|
||||
device T* out_vec [[buffer(2)]],
|
||||
const constant int& in_vec_size [[buffer(3)]],
|
||||
const constant int& out_vec_size [[buffer(4)]],
|
||||
const constant int& vector_batch_stride [[buffer(5)]],
|
||||
const constant int& matrix_batch_stride [[buffer(6)]],
|
||||
uint3 tid [[threadgroup_position_in_grid]],
|
||||
uint simd_gid [[simdgroup_index_in_threadgroup]],
|
||||
uint simd_lid [[thread_index_in_simdgroup]]) {
|
||||
MLX_MTL_CONST int SIMD_SIZE = 32;
|
||||
|
||||
static_assert(BN == SIMD_SIZE, "gemv block must have a width of SIMD_SIZE");
|
||||
template <
|
||||
typename T,
|
||||
const int BM, /* Threadgroup rows (in threads) */
|
||||
const int BN, /* Threadgroup cols (in threads) */
|
||||
const int TM, /* Thread rows (in elements) */
|
||||
const int TN > /* Thread cols (in elements) */
|
||||
struct GEMVKernel {
|
||||
|
||||
// - The matrix of size (M = out_vec_size, N = in_vec_size) is divided up
|
||||
// into blocks of (BM * TM, BN * TN) divided amoung threadgroups
|
||||
// - Every thread works on a block of (TM, TN)
|
||||
// - We assume each thead group is launched with (BN, BM, 1) threads
|
||||
//
|
||||
// 1. A thread loads TN elements each from mat along TM contiguous rows
|
||||
// and the corresponding scalar from the vector
|
||||
// 2. The thread then multiplies and adds to accumulate its local result for the block
|
||||
// 3. At the end, each thread has accumulated results over all blocks across the rows
|
||||
// These are then summed up across the threadgroup
|
||||
// 4. Each threadgroup writes its accumulated BN * TN outputs
|
||||
//
|
||||
// Edge case handling:
|
||||
// - The threadgroup with the largest tid will have blocks that exceed the matrix
|
||||
// * The blocks that start outside the matrix are never read (thread results remain zero)
|
||||
// * The last thread that partialy overlaps with the matrix is shifted inwards
|
||||
// such that the thread block fits exactly in the matrix
|
||||
static_assert(BN == SIMD_SIZE, "gemv block must have a width of SIMD_SIZE");
|
||||
|
||||
// - The matrix of size (M = out_vec_size, N = in_vec_size) is divided up
|
||||
// into blocks of (BM * TM, BN * TN) divided amoung threadgroups
|
||||
// - Every thread works on a block of (TM, TN)
|
||||
// - We assume each thead group is launched with (BN, BM, 1) threads
|
||||
//
|
||||
// 1. A thread loads TN elements each from mat along TM contiguous rows
|
||||
// and the corresponding scalar from the vector
|
||||
// 2. The thread then multiplies and adds to accumulate its local result for the block
|
||||
// 3. At the end, each thread has accumulated results over all blocks across the rows
|
||||
// These are then summed up across the threadgroup
|
||||
// 4. Each threadgroup writes its accumulated BN * TN outputs
|
||||
//
|
||||
// Edge case handling:
|
||||
// - The threadgroup with the largest tid will have blocks that exceed the matrix
|
||||
// * The blocks that start outside the matrix are never read (thread results remain zero)
|
||||
// * The last thread that partialy overlaps with the matrix is shifted inwards
|
||||
// such that the thread block fits exactly in the matrix
|
||||
|
||||
MLX_MTL_CONST short tgp_mem_size = BN * TN * 2;
|
||||
|
||||
static METAL_FUNC void run(
|
||||
const device T* mat,
|
||||
const device T* in_vec,
|
||||
device T* out_vec,
|
||||
const constant int& in_vec_size [[buffer(3)]],
|
||||
const constant int& out_vec_size [[buffer(4)]],
|
||||
threadgroup T* tgp_memory [[threadgroup(0)]],
|
||||
uint3 tid [[threadgroup_position_in_grid]],
|
||||
uint3 lid [[thread_position_in_threadgroup]],
|
||||
uint simd_gid [[simdgroup_index_in_threadgroup]],
|
||||
uint simd_lid [[thread_index_in_simdgroup]]) {
|
||||
|
||||
// Appease compiler
|
||||
(void)lid;
|
||||
|
||||
// Update batch offsets
|
||||
in_vec += tid.z * vector_batch_stride;
|
||||
mat += tid.z * matrix_batch_stride;
|
||||
out_vec += tid.z * out_vec_size;
|
||||
|
||||
// Threadgroup in_vec cache
|
||||
threadgroup T in_vec_block[BN][TN * 2];
|
||||
threadgroup T* in_vec_block = tgp_memory + simd_lid * TN * 2;
|
||||
|
||||
// Thread local accumulation results
|
||||
thread T result[TM] = {0};
|
||||
@ -69,7 +75,7 @@ template <typename T,
|
||||
|
||||
// Exit simdgroup if rows out of bound
|
||||
if(out_row >= out_vec_size)
|
||||
return;
|
||||
return;
|
||||
|
||||
// Adjust tail simdgroup to ensure in bound reads
|
||||
out_row = out_row + TM <= out_vec_size ? out_row : out_vec_size - TM;
|
||||
@ -79,62 +85,304 @@ template <typename T,
|
||||
|
||||
// Loop over in_vec in blocks of BN * TN
|
||||
for(int bn = simd_lid * TN; bn < in_vec_size; bn += BN * TN) {
|
||||
threadgroup_barrier(mem_flags::mem_threadgroup);
|
||||
// Prefetch in_vector for threadgroup use
|
||||
if(simd_gid == 0) {
|
||||
// Main load loop
|
||||
if(bn + TN <= in_vec_size) {
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
in_vec_block[simd_lid][tn] = in_vec[bn + tn];
|
||||
}
|
||||
} else { // Edgecase
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
in_vec_block[simd_lid][tn] = bn + tn < in_vec_size ? in_vec[bn + tn] : 0;
|
||||
}
|
||||
}
|
||||
}
|
||||
threadgroup_barrier(mem_flags::mem_threadgroup);
|
||||
|
||||
// Load for all rows
|
||||
#pragma clang loop unroll(full)
|
||||
threadgroup_barrier(mem_flags::mem_threadgroup);
|
||||
|
||||
// Prefetch in_vector for threadgroup use
|
||||
if(simd_gid == 0) {
|
||||
// Main load loop
|
||||
if(bn + TN <= in_vec_size) {
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
in_vec_block[tn] = in_vec[bn + tn];
|
||||
}
|
||||
|
||||
} else { // Edgecase
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
in_vec_block[tn] = bn + tn < in_vec_size ? in_vec[bn + tn] : 0;
|
||||
}
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
threadgroup_barrier(mem_flags::mem_threadgroup);
|
||||
|
||||
// Load for all rows
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
v_coeff[tn] = in_vec_block[tn];
|
||||
}
|
||||
|
||||
// Per thread work loop
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tm = 0; tm < TM; tm++) {
|
||||
|
||||
// Load for the row
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
v_coeff[tn] = in_vec_block[simd_lid][tn];
|
||||
inter[tn] = mat[tm * in_vec_size + bn + tn];
|
||||
}
|
||||
|
||||
// Per thread work loop
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tm = 0; tm < TM; tm++) {
|
||||
// Load for the row
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
inter[tn] = mat[tm * in_vec_size + bn + tn];
|
||||
}
|
||||
|
||||
// Accumulate results
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
result[tm] += inter[tn] * v_coeff[tn];
|
||||
}
|
||||
// Accumulate results
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
result[tm] += inter[tn] * v_coeff[tn];
|
||||
}
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
// Simdgroup accumulations
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tm = 0; tm < TM; tm++) {
|
||||
result[tm] = simd_sum(result[tm]);
|
||||
result[tm] = simd_sum(result[tm]);
|
||||
}
|
||||
|
||||
// Write outputs
|
||||
if(simd_lid == 0) {
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tm = 0; tm < TM; tm++) {
|
||||
out_vec[out_row + tm] = result[tm];
|
||||
}
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tm = 0; tm < TM; tm++) {
|
||||
out_vec[out_row + tm] = result[tm];
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
};
|
||||
|
||||
///////////////////////////////////////////////////////////////////////////////
|
||||
/// Vector matrix multiplication
|
||||
///////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
template <
|
||||
typename T,
|
||||
const int BM, /* Threadgroup rows (in threads) */
|
||||
const int BN, /* Threadgroup cols (in threads) */
|
||||
const int TM, /* Thread rows (in elements) */
|
||||
const int TN > /* Thread cols (in elements) */
|
||||
struct GEMVTKernel {
|
||||
|
||||
// - The matrix of size (M = in_vec_size, N = out_vec_size) is divided up
|
||||
// into blocks of (BM * TM, BN * TN) divided amoung threadgroups
|
||||
// - Every thread works on a block of (TM, TN)
|
||||
// - We assume each thead group is launched with (BN, BM, 1) threads
|
||||
//
|
||||
// 1. A thread loads TN elements each from mat along TM contiguous rows
|
||||
// and the corresponding scalar from the vector
|
||||
// 2. The thread then multiplies and adds to accumulate its local result for the block
|
||||
// 3. At the end, each thread has accumulated results over all blocks across the rows
|
||||
// These are then summed up across the threadgroup
|
||||
// 4. Each threadgroup writes its accumulated BN * TN outputs
|
||||
//
|
||||
// Edge case handling:
|
||||
// - The threadgroup with the largest tid will have blocks that exceed the matrix
|
||||
// * The blocks that start outside the matrix are never read (thread results remain zero)
|
||||
// * The last thread that partialy overlaps with the matrix is shifted inwards
|
||||
// such that the thread block fits exactly in the matrix
|
||||
|
||||
|
||||
MLX_MTL_CONST short tgp_mem_size = BN * BM * TN;
|
||||
|
||||
static METAL_FUNC void run(
|
||||
const device T* mat,
|
||||
const device T* in_vec,
|
||||
device T* out_vec,
|
||||
const constant int& in_vec_size [[buffer(3)]],
|
||||
const constant int& out_vec_size [[buffer(4)]],
|
||||
threadgroup T* tgp_memory [[threadgroup(0)]],
|
||||
uint3 tid [[threadgroup_position_in_grid]],
|
||||
uint3 lid [[thread_position_in_threadgroup]],
|
||||
uint simd_gid [[simdgroup_index_in_threadgroup]],
|
||||
uint simd_lid [[thread_index_in_simdgroup]]) {
|
||||
|
||||
// Appease compiler
|
||||
(void)simd_gid;
|
||||
(void)simd_lid;
|
||||
|
||||
// Thread local accumulation results
|
||||
T result[TN] = {0};
|
||||
T inter[TN];
|
||||
T v_coeff[TM];
|
||||
|
||||
// Threadgroup accumulation results
|
||||
threadgroup T* tgp_results = tgp_memory + lid.x * BM * TN;
|
||||
|
||||
int out_col = (tid.x * BN + lid.x) * TN;
|
||||
int in_row = lid.y * TM;
|
||||
|
||||
// Edgecase handling
|
||||
if (out_col < out_vec_size) {
|
||||
|
||||
out_col = out_col + TN < out_vec_size ? out_col : out_vec_size - TN;
|
||||
|
||||
// Per thread accumulation main loop
|
||||
int bm = in_row;
|
||||
for(; bm < in_vec_size; bm += BM * TM) {
|
||||
// Adding a threadgroup_barrier improves performance slightly
|
||||
// This is possibly it may help exploit cache better
|
||||
threadgroup_barrier(mem_flags::mem_none);
|
||||
|
||||
if(bm + TM <= in_vec_size) {
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tm = 0; tm < TM; tm++) {
|
||||
v_coeff[tm] = in_vec[bm + tm];
|
||||
}
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tm = 0; tm < TM; tm++) {
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
inter[tn] = mat[(bm + tm) * out_vec_size + out_col + tn];
|
||||
}
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
result[tn] += v_coeff[tm] * inter[tn];
|
||||
}
|
||||
}
|
||||
|
||||
} else { // Edgecase handling
|
||||
for(int tm = 0; bm + tm < in_vec_size; tm++) {
|
||||
v_coeff[tm] = in_vec[bm + tm];
|
||||
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
inter[tn] = mat[(bm + tm) * out_vec_size + out_col + tn];
|
||||
}
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
result[tn] += v_coeff[tm] * inter[tn];
|
||||
}
|
||||
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
// Threadgroup collection
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for(int i = 0; i < TN; i++) {
|
||||
tgp_results[lid.y * TN + i] = result[i];
|
||||
}
|
||||
|
||||
threadgroup_barrier(mem_flags::mem_threadgroup);
|
||||
|
||||
// Threadgroup accumulation and writing out results
|
||||
if(lid.y == 0 && out_col < out_vec_size) {
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for(int i = 1; i < BM; i++) {
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for(int j = 0; j < TN; j++) {
|
||||
result[j] += tgp_results[i * TN + j];
|
||||
}
|
||||
}
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for(int j = 0; j < TN; j++) {
|
||||
out_vec[out_col + j] = result[j];
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
|
||||
};
|
||||
|
||||
///////////////////////////////////////////////////////////////////////////////
|
||||
/// Matrix vector multiplication
|
||||
///////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
template <
|
||||
typename T,
|
||||
const int BM, /* Threadgroup rows (in threads) */
|
||||
const int BN, /* Threadgroup cols (in threads) */
|
||||
const int TM, /* Thread rows (in elements) */
|
||||
const int TN> /* Thread cols (in elements) */
|
||||
[[kernel, max_total_threads_per_threadgroup(BM * BN)]] void gemv(
|
||||
const device T* mat [[buffer(0)]],
|
||||
const device T* in_vec [[buffer(1)]],
|
||||
device T* out_vec [[buffer(2)]],
|
||||
const constant int& in_vec_size [[buffer(3)]],
|
||||
const constant int& out_vec_size [[buffer(4)]],
|
||||
const constant int& vector_batch_stride [[buffer(5)]],
|
||||
const constant int& matrix_batch_stride [[buffer(6)]],
|
||||
uint3 tid [[threadgroup_position_in_grid]],
|
||||
uint3 lid [[thread_position_in_threadgroup]],
|
||||
uint simd_gid [[simdgroup_index_in_threadgroup]],
|
||||
uint simd_lid [[thread_index_in_simdgroup]]) {
|
||||
|
||||
using gemv_kernel = GEMVKernel<T, BM, BN, TM, TN>;
|
||||
threadgroup T tgp_memory[gemv_kernel::tgp_mem_size];
|
||||
|
||||
// Update batch offsets
|
||||
in_vec += tid.z * vector_batch_stride;
|
||||
mat += tid.z * matrix_batch_stride;
|
||||
out_vec += tid.z * out_vec_size;
|
||||
|
||||
gemv_kernel::run(
|
||||
mat,
|
||||
in_vec,
|
||||
out_vec,
|
||||
in_vec_size,
|
||||
out_vec_size,
|
||||
tgp_memory,
|
||||
tid,
|
||||
lid,
|
||||
simd_gid,
|
||||
simd_lid
|
||||
);
|
||||
|
||||
}
|
||||
|
||||
#define instantiate_gemv(name, itype, bm, bn, tm, tn) \
|
||||
template <
|
||||
typename T,
|
||||
const int BM, /* Threadgroup rows (in threads) */
|
||||
const int BN, /* Threadgroup cols (in threads) */
|
||||
const int TM, /* Thread rows (in elements) */
|
||||
const int TN> /* Thread cols (in elements) */
|
||||
[[kernel, max_total_threads_per_threadgroup(BM * BN)]] void gemv_nc(
|
||||
const device T* mat [[buffer(0)]],
|
||||
const device T* in_vec [[buffer(1)]],
|
||||
device T* out_vec [[buffer(2)]],
|
||||
const constant int& in_vec_size [[buffer(3)]],
|
||||
const constant int& out_vec_size [[buffer(4)]],
|
||||
const constant int& nc_dim [[buffer(5)]],
|
||||
const device int* nc_shape [[buffer(6)]],
|
||||
const device size_t* nc_strides_vec [[buffer(7)]],
|
||||
const device size_t* nc_strides_mat [[buffer(8)]],
|
||||
uint3 tid [[threadgroup_position_in_grid]],
|
||||
uint3 lid [[thread_position_in_threadgroup]],
|
||||
uint simd_gid [[simdgroup_index_in_threadgroup]],
|
||||
uint simd_lid [[thread_index_in_simdgroup]]) {
|
||||
|
||||
using gemv_kernel = GEMVKernel<T, BM, BN, TM, TN>;
|
||||
threadgroup T tgp_memory[gemv_kernel::tgp_mem_size];
|
||||
|
||||
// Update batch offsets
|
||||
in_vec += elem_to_loc(tid.z, nc_shape, nc_strides_vec, nc_dim);
|
||||
mat += elem_to_loc(tid.z, nc_shape, nc_strides_mat, nc_dim);
|
||||
out_vec += tid.z * out_vec_size;
|
||||
|
||||
gemv_kernel::run(
|
||||
mat,
|
||||
in_vec,
|
||||
out_vec,
|
||||
in_vec_size,
|
||||
out_vec_size,
|
||||
tgp_memory,
|
||||
tid,
|
||||
lid,
|
||||
simd_gid,
|
||||
simd_lid
|
||||
);
|
||||
|
||||
}
|
||||
|
||||
|
||||
#define instantiate_gemv_c(name, itype, bm, bn, tm, tn) \
|
||||
template [[host_name("gemv_" #name "_bm" #bm "_bn" #bn "_tm" #tm "_tn" #tn)]] \
|
||||
[[kernel]] void gemv<itype, bm, bn, tm, tn>( \
|
||||
const device itype* mat [[buffer(0)]], \
|
||||
@ -145,28 +393,51 @@ template <typename T,
|
||||
const constant int& vector_batch_stride [[buffer(5)]], \
|
||||
const constant int& matrix_batch_stride [[buffer(6)]], \
|
||||
uint3 tid [[threadgroup_position_in_grid]], \
|
||||
uint3 lid [[thread_position_in_threadgroup]], \
|
||||
uint simd_gid [[simdgroup_index_in_threadgroup]], \
|
||||
uint simd_lid [[thread_index_in_simdgroup]]);
|
||||
|
||||
#define instantiate_gemv_blocks(name, itype) \
|
||||
instantiate_gemv(name, itype, 4, 32, 1, 4) \
|
||||
instantiate_gemv(name, itype, 4, 32, 4, 4) \
|
||||
instantiate_gemv(name, itype, 8, 32, 4, 4)
|
||||
#define instantiate_gemv_nc(name, itype, bm, bn, tm, tn) \
|
||||
template [[host_name("gemv_" #name "_bm" #bm "_bn" #bn "_tm" #tm "_tn" #tn "_nc")]] \
|
||||
[[kernel]] void gemv_nc<itype, bm, bn, tm, tn>( \
|
||||
const device itype* mat [[buffer(0)]], \
|
||||
const device itype* vec [[buffer(1)]], \
|
||||
device itype* out [[buffer(2)]], \
|
||||
const constant int& in_vec_size [[buffer(3)]], \
|
||||
const constant int& out_vec_size [[buffer(4)]], \
|
||||
const constant int& nc_dim [[buffer(5)]], \
|
||||
const device int* nc_shape [[buffer(6)]], \
|
||||
const device size_t* nc_strides_vec [[buffer(7)]], \
|
||||
const device size_t* nc_strides_mat [[buffer(8)]], \
|
||||
uint3 tid [[threadgroup_position_in_grid]], \
|
||||
uint3 lid [[thread_position_in_threadgroup]], \
|
||||
uint simd_gid [[simdgroup_index_in_threadgroup]], \
|
||||
uint simd_lid [[thread_index_in_simdgroup]]);
|
||||
|
||||
instantiate_gemv_blocks(float32, float)
|
||||
instantiate_gemv_blocks(float16, half)
|
||||
instantiate_gemv_blocks(bfloat16, bfloat16_t)
|
||||
#define instantiate_gemv(name, itype, bm, bn, tm, tn) \
|
||||
instantiate_gemv_c(name, itype, bm, bn, tm, tn) \
|
||||
instantiate_gemv_nc(name, itype, bm, bn, tm, tn)
|
||||
|
||||
#define instantiate_gemv_blocks(name, itype) \
|
||||
instantiate_gemv(name, itype, 4, 32, 1, 4) \
|
||||
instantiate_gemv(name, itype, 4, 32, 4, 4) \
|
||||
instantiate_gemv(name, itype, 8, 32, 4, 4)
|
||||
|
||||
instantiate_gemv_blocks(float32, float);
|
||||
instantiate_gemv_blocks(float16, half);
|
||||
instantiate_gemv_blocks(bfloat16, bfloat16_t);
|
||||
|
||||
///////////////////////////////////////////////////////////////////////////////
|
||||
/// Vector matrix multiplication
|
||||
///////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
template <typename T,
|
||||
const int BM, /* Threadgroup rows (in threads) */
|
||||
const int BN, /* Threadgroup cols (in threads) */
|
||||
const int TM, /* Thread rows (in elements) */
|
||||
const int TN> /* Thread cols (in elements) */
|
||||
[[kernel]] void gemv_t(
|
||||
template <
|
||||
typename T,
|
||||
const int BM, /* Threadgroup rows (in threads) */
|
||||
const int BN, /* Threadgroup cols (in threads) */
|
||||
const int TM, /* Thread rows (in elements) */
|
||||
const int TN> /* Thread cols (in elements) */
|
||||
[[kernel, max_total_threads_per_threadgroup(BM * BN)]] void gemv_t(
|
||||
const device T* mat [[buffer(0)]],
|
||||
const device T* in_vec [[buffer(1)]],
|
||||
device T* out_vec [[buffer(2)]],
|
||||
@ -175,110 +446,77 @@ template <typename T,
|
||||
const constant int& vector_batch_stride [[buffer(5)]],
|
||||
const constant int& matrix_batch_stride [[buffer(6)]],
|
||||
uint3 tid [[threadgroup_position_in_grid]],
|
||||
uint3 lid [[thread_position_in_threadgroup]]) {
|
||||
uint3 lid [[thread_position_in_threadgroup]],
|
||||
uint simd_gid [[simdgroup_index_in_threadgroup]],
|
||||
uint simd_lid [[thread_index_in_simdgroup]]) {
|
||||
|
||||
// - The matrix of size (M = in_vec_size, N = out_vec_size) is divided up
|
||||
// into blocks of (BM * TM, BN * TN) divided amoung threadgroups
|
||||
// - Every thread works on a block of (TM, TN)
|
||||
// - We assume each thead group is launched with (BN, BM, 1) threads
|
||||
//
|
||||
// 1. A thread loads TN elements each from mat along TM contiguous rows
|
||||
// and the corresponding scalar from the vector
|
||||
// 2. The thread then multiplies and adds to accumulate its local result for the block
|
||||
// 3. At the end, each thread has accumulated results over all blocks across the rows
|
||||
// These are then summed up across the threadgroup
|
||||
// 4. Each threadgroup writes its accumulated BN * TN outputs
|
||||
//
|
||||
// Edge case handling:
|
||||
// - The threadgroup with the largest tid will have blocks that exceed the matrix
|
||||
// * The blocks that start outside the matrix are never read (thread results remain zero)
|
||||
// * The last thread that partialy overlaps with the matrix is shifted inwards
|
||||
// such that the thread block fits exactly in the matrix
|
||||
using gemv_kernel = GEMVTKernel<T, BM, BN, TM, TN>;
|
||||
threadgroup T tgp_memory[gemv_kernel::tgp_mem_size];
|
||||
|
||||
// Update batch offsets
|
||||
in_vec += tid.z * vector_batch_stride;
|
||||
mat += tid.z * matrix_batch_stride;
|
||||
out_vec += tid.z * out_vec_size;
|
||||
|
||||
// Thread local accumulation results
|
||||
T result[TN] = {0};
|
||||
T inter[TN];
|
||||
T v_coeff[TM];
|
||||
// Update batch offsets
|
||||
in_vec += tid.z * vector_batch_stride;
|
||||
mat += tid.z * matrix_batch_stride;
|
||||
out_vec += tid.z * out_vec_size;
|
||||
|
||||
// Threadgroup accumulation results
|
||||
threadgroup T tgp_results[BN][BM][TM];
|
||||
gemv_kernel::run(
|
||||
mat,
|
||||
in_vec,
|
||||
out_vec,
|
||||
in_vec_size,
|
||||
out_vec_size,
|
||||
tgp_memory,
|
||||
tid,
|
||||
lid,
|
||||
simd_gid,
|
||||
simd_lid
|
||||
);
|
||||
}
|
||||
|
||||
int out_col = (tid.x * BN + lid.x) * TN;
|
||||
int in_row = lid.y * TM;
|
||||
template <
|
||||
typename T,
|
||||
const int BM, /* Threadgroup rows (in threads) */
|
||||
const int BN, /* Threadgroup cols (in threads) */
|
||||
const int TM, /* Thread rows (in elements) */
|
||||
const int TN> /* Thread cols (in elements) */
|
||||
[[kernel, max_total_threads_per_threadgroup(BM * BN)]] void gemv_t_nc(
|
||||
const device T* mat [[buffer(0)]],
|
||||
const device T* in_vec [[buffer(1)]],
|
||||
device T* out_vec [[buffer(2)]],
|
||||
const constant int& in_vec_size [[buffer(3)]],
|
||||
const constant int& out_vec_size [[buffer(4)]],
|
||||
const constant int& nc_dim [[buffer(5)]],
|
||||
const device int* nc_shape [[buffer(6)]],
|
||||
const device size_t* nc_strides_vec [[buffer(7)]],
|
||||
const device size_t* nc_strides_mat [[buffer(8)]],
|
||||
uint3 tid [[threadgroup_position_in_grid]],
|
||||
uint3 lid [[thread_position_in_threadgroup]],
|
||||
uint simd_gid [[simdgroup_index_in_threadgroup]],
|
||||
uint simd_lid [[thread_index_in_simdgroup]]) {
|
||||
|
||||
// Edgecase handling
|
||||
if (out_col < out_vec_size) {
|
||||
// Edgecase handling
|
||||
out_col = out_col + TN < out_vec_size ? out_col : out_vec_size - TN;
|
||||
using gemv_kernel = GEMVTKernel<T, BM, BN, TM, TN>;
|
||||
threadgroup T tgp_memory[gemv_kernel::tgp_mem_size];
|
||||
|
||||
// Per thread accumulation main loop
|
||||
int bm = in_row;
|
||||
for(; bm < in_vec_size; bm += BM * TM) {
|
||||
// Adding a threadgroup_barrier improves performance slightly
|
||||
// This is possibly it may help exploit cache better
|
||||
threadgroup_barrier(mem_flags::mem_none);
|
||||
// Update batch offsets
|
||||
in_vec += elem_to_loc(tid.z, nc_shape, nc_strides_vec, nc_dim);
|
||||
mat += elem_to_loc(tid.z, nc_shape, nc_strides_mat, nc_dim);
|
||||
out_vec += tid.z * out_vec_size;
|
||||
|
||||
if(bm + TM <= in_vec_size) {
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tm = 0; tm < TM; tm++) {
|
||||
v_coeff[tm] = in_vec[bm + tm];
|
||||
}
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for(int tm = 0; tm < TM; tm++) {
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
inter[tn] = mat[(bm + tm) * out_vec_size + out_col + tn];
|
||||
}
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
result[tn] += v_coeff[tm] * inter[tn];
|
||||
}
|
||||
}
|
||||
|
||||
} else { // Edgecase handling
|
||||
for(int tm = 0; bm + tm < in_vec_size; tm++) {
|
||||
v_coeff[tm] = in_vec[bm + tm];
|
||||
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
inter[tn] = mat[(bm + tm) * out_vec_size + out_col + tn];
|
||||
}
|
||||
for(int tn = 0; tn < TN; tn++) {
|
||||
result[tn] += v_coeff[tm] * inter[tn];
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
// Threadgroup collection
|
||||
for(int i = 0; i < TN; i++) {
|
||||
tgp_results[lid.x][lid.y][i] = result[i];
|
||||
}
|
||||
threadgroup_barrier(mem_flags::mem_threadgroup);
|
||||
|
||||
if(lid.y == 0 && out_col < out_vec_size) {
|
||||
// Threadgroup accumulation
|
||||
#pragma clang loop unroll(full)
|
||||
for(int i = 1; i < BM; i++) {
|
||||
for(int j = 0; j < TN; j++) {
|
||||
result[j] += tgp_results[lid.x][i][j];
|
||||
}
|
||||
}
|
||||
|
||||
for(int j = 0; j < TN; j++) {
|
||||
out_vec[out_col + j] = result[j];
|
||||
}
|
||||
}
|
||||
gemv_kernel::run(
|
||||
mat,
|
||||
in_vec,
|
||||
out_vec,
|
||||
in_vec_size,
|
||||
out_vec_size,
|
||||
tgp_memory,
|
||||
tid,
|
||||
lid,
|
||||
simd_gid,
|
||||
simd_lid
|
||||
);
|
||||
|
||||
}
|
||||
|
||||
#define instantiate_gemv_t(name, itype, bm, bn, tm, tn) \
|
||||
#define instantiate_gemv_t_c(name, itype, bm, bn, tm, tn) \
|
||||
template [[host_name("gemv_t_" #name "_bm" #bm "_bn" #bn "_tm" #tm "_tn" #tn)]] \
|
||||
[[kernel]] void gemv_t<itype, bm, bn, tm, tn>( \
|
||||
const device itype* mat [[buffer(0)]], \
|
||||
@ -289,16 +527,39 @@ template <typename T,
|
||||
const constant int& vector_batch_stride [[buffer(5)]], \
|
||||
const constant int& matrix_batch_stride [[buffer(6)]], \
|
||||
uint3 tid [[threadgroup_position_in_grid]], \
|
||||
uint3 lid [[thread_position_in_threadgroup]]);
|
||||
uint3 lid [[thread_position_in_threadgroup]], \
|
||||
uint simd_gid [[simdgroup_index_in_threadgroup]], \
|
||||
uint simd_lid [[thread_index_in_simdgroup]]);
|
||||
|
||||
#define instantiate_gemv_t_nc(name, itype, bm, bn, tm, tn) \
|
||||
template [[host_name("gemv_t_" #name "_bm" #bm "_bn" #bn "_tm" #tm "_tn" #tn "_nc")]] \
|
||||
[[kernel]] void gemv_t_nc<itype, bm, bn, tm, tn>( \
|
||||
const device itype* mat [[buffer(0)]], \
|
||||
const device itype* vec [[buffer(1)]], \
|
||||
device itype* out [[buffer(2)]], \
|
||||
const constant int& in_vec_size [[buffer(3)]], \
|
||||
const constant int& out_vec_size [[buffer(4)]], \
|
||||
const constant int& nc_dim [[buffer(5)]], \
|
||||
const device int* nc_shape [[buffer(6)]], \
|
||||
const device size_t* nc_strides_vec [[buffer(7)]], \
|
||||
const device size_t* nc_strides_mat [[buffer(8)]], \
|
||||
uint3 tid [[threadgroup_position_in_grid]], \
|
||||
uint3 lid [[thread_position_in_threadgroup]], \
|
||||
uint simd_gid [[simdgroup_index_in_threadgroup]], \
|
||||
uint simd_lid [[thread_index_in_simdgroup]]);
|
||||
|
||||
#define instantiate_gemv_t(name, itype, bm, bn, tm, tn) \
|
||||
instantiate_gemv_t_c(name, itype, bm, bn, tm, tn) \
|
||||
instantiate_gemv_t_nc(name, itype, bm, bn, tm, tn)
|
||||
|
||||
#define instantiate_gemv_t_blocks(name, itype) \
|
||||
instantiate_gemv_t(name, itype, 8, 8, 4, 1) \
|
||||
instantiate_gemv_t(name, itype, 8, 8, 4, 4) \
|
||||
instantiate_gemv_t(name, itype, 8, 16, 4, 4) \
|
||||
instantiate_gemv_t(name, itype, 8, 32, 4, 4) \
|
||||
instantiate_gemv_t(name, itype, 8, 64, 4, 4) \
|
||||
instantiate_gemv_t(name, itype, 8, 128, 4, 4)
|
||||
instantiate_gemv_t(name, itype, 8, 8, 4, 1) \
|
||||
instantiate_gemv_t(name, itype, 8, 8, 4, 4) \
|
||||
instantiate_gemv_t(name, itype, 8, 16, 4, 4) \
|
||||
instantiate_gemv_t(name, itype, 8, 32, 4, 4) \
|
||||
instantiate_gemv_t(name, itype, 8, 64, 4, 4) \
|
||||
instantiate_gemv_t(name, itype, 8, 128, 4, 4)
|
||||
|
||||
instantiate_gemv_t_blocks(float32, float)
|
||||
instantiate_gemv_t_blocks(float16, half)
|
||||
instantiate_gemv_t_blocks(bfloat16, bfloat16_t)
|
||||
instantiate_gemv_t_blocks(float32, float);
|
||||
instantiate_gemv_t_blocks(float16, half);
|
||||
instantiate_gemv_t_blocks(bfloat16, bfloat16_t);
|
||||
|
||||
@ -9,7 +9,7 @@
|
||||
#define MLX_MTL_CONST static constant constexpr const
|
||||
#define MLX_MTL_LOOP_UNROLL _Pragma("clang loop unroll(full)")
|
||||
|
||||
using namespace metal;\
|
||||
using namespace metal;
|
||||
|
||||
// Based on GPU merge sort algorithm at https://github.com/NVIDIA/cccl/tree/main/cub/cub
|
||||
|
||||
|
||||
@ -343,10 +343,18 @@ void Matmul::eval_gpu(const std::vector<array>& inputs, array& out) {
|
||||
int mat_rows = transpose_mat ? in_vector_len : out_vector_len;
|
||||
|
||||
int batch_size_mat = mat.data_size() / (mat_cols * mat_rows);
|
||||
int stride_mat = batch_size_mat == batch_size_out ? mat_cols * mat_rows : 0;
|
||||
int stride_mat = batch_size_mat == 1 ? 0 : mat_cols * mat_rows;
|
||||
|
||||
int batch_size_vec = vec.data_size() / in_vector_len;
|
||||
int stride_vec = batch_size_vec == batch_size_out ? in_vector_len : 0;
|
||||
int stride_vec = batch_size_vec == 1 ? 0 : in_vector_len;
|
||||
|
||||
// Determine if inputs have simple batching / broadcasting
|
||||
bool contiguous_kernel =
|
||||
(batch_size_out == std::max(batch_size_mat, batch_size_vec) &&
|
||||
(batch_size_mat == batch_size_vec ||
|
||||
std::min(batch_size_mat, batch_size_vec) == 1));
|
||||
|
||||
int nc_dim = out.ndim() - 2;
|
||||
|
||||
// Determine dispatch kernel
|
||||
int tm = 4, tn = 4;
|
||||
@ -383,6 +391,10 @@ void Matmul::eval_gpu(const std::vector<array>& inputs, array& out) {
|
||||
|
||||
kname << "_bm" << bm << "_bn" << bn << "_tm" << tm << "_tn" << tn;
|
||||
|
||||
if (!contiguous_kernel) {
|
||||
kname << "_nc";
|
||||
}
|
||||
|
||||
// Encode and dispatch kernel
|
||||
auto compute_encoder = d.get_command_encoder(s.index);
|
||||
auto kernel = d.get_kernel(kname.str());
|
||||
@ -398,8 +410,22 @@ void Matmul::eval_gpu(const std::vector<array>& inputs, array& out) {
|
||||
|
||||
compute_encoder->setBytes(&in_vector_len, sizeof(int), 3);
|
||||
compute_encoder->setBytes(&out_vector_len, sizeof(int), 4);
|
||||
compute_encoder->setBytes(&stride_vec, sizeof(int), 5);
|
||||
compute_encoder->setBytes(&stride_mat, sizeof(int), 6);
|
||||
|
||||
if (contiguous_kernel) {
|
||||
compute_encoder->setBytes(&stride_vec, sizeof(int), 5);
|
||||
compute_encoder->setBytes(&stride_mat, sizeof(int), 6);
|
||||
} else {
|
||||
// In case of complex broadcasting, we consider the shape[:-2] and
|
||||
// strides [:-2] to determine the location of a batch
|
||||
// nc_dim = out.ndim() - 2
|
||||
compute_encoder->setBytes(&nc_dim, sizeof(int), 5);
|
||||
compute_encoder->setBytes(out.shape().data(), nc_dim * sizeof(int), 6);
|
||||
compute_encoder->setBytes(
|
||||
vec.strides().data(), nc_dim * sizeof(size_t), 7);
|
||||
compute_encoder->setBytes(
|
||||
mat.strides().data(), nc_dim * sizeof(size_t), 8);
|
||||
}
|
||||
|
||||
compute_encoder->dispatchThreadgroups(grid_dims, group_dims);
|
||||
|
||||
d.get_command_buffer(s.index)->addCompletedHandler(
|
||||
|
||||
@ -340,6 +340,7 @@ class TestBlas(mlx_tests.MLXTestCase):
|
||||
((32, 128, 64), (32, 64, 1)),
|
||||
((128, 64), (32, 64, 1)),
|
||||
((32, 128, 64), (64, 1)),
|
||||
((2, 1, 8, 1, 6, 128), (2, 1, 8, 4, 128, 1)),
|
||||
):
|
||||
self.__gemv_test(
|
||||
shape_mat, shape_vec, mat_first=True, np_dtype=np_dtype
|
||||
@ -350,6 +351,7 @@ class TestBlas(mlx_tests.MLXTestCase):
|
||||
((32, 1, 128), (32, 128, 64)),
|
||||
((32, 1, 128), (128, 64)),
|
||||
((1, 128), (32, 128, 64)),
|
||||
((1, 8, 4, 1, 128), (1, 8, 1, 128, 6)),
|
||||
):
|
||||
self.__gemv_test(
|
||||
shape_mat, shape_vec, mat_first=False, np_dtype=np_dtype
|
||||
|
||||
Loading…
Reference in New Issue
Block a user