vulkan: use vec dot for matrix matrix multiplications (#16056)

* vulkan: Change the mul_mm shared memory and register caching system to use vec2 instead of scalars, to enable using dot2 instructions

* use fma instead of dot to fix Nvidia and Apple performance issues
This commit is contained in:
Ruben Ortlam
2025-09-20 10:42:56 +02:00
committed by GitHub
parent 459c0c2c1a
commit 803dac2e48
4 changed files with 187 additions and 199 deletions
+15 -15
View File
@@ -31,10 +31,10 @@
#include "types.comp"
#ifndef LOAD_VEC_A
#define LOAD_VEC_A 1
#define LOAD_VEC_A 2
#endif
#ifndef LOAD_VEC_B
#define LOAD_VEC_B 1
#define LOAD_VEC_B 2
#endif
#if !defined(TO_FLOAT_TYPE)
@@ -98,13 +98,13 @@ layout (constant_id = 9) const uint TK = 1; // Only needed for coopmat
layout (constant_id = 10) const uint WARP = 32;
#ifdef COOPMAT
#define SHMEM_STRIDE (BK + 8)
#define SHMEM_STRIDE (BK / 2 + 4)
#else
#define SHMEM_STRIDE (BK + 1)
#define SHMEM_STRIDE (BK / 2 + 1)
#endif
shared FLOAT_TYPE buf_a[BM * SHMEM_STRIDE];
shared FLOAT_TYPE buf_b[BN * SHMEM_STRIDE];
shared FLOAT_TYPE_VEC2 buf_a[BM * SHMEM_STRIDE];
shared FLOAT_TYPE_VEC2 buf_b[BN * SHMEM_STRIDE];
#define NUM_WARPS (BLOCK_SIZE / WARP)
@@ -302,8 +302,8 @@ void main() {
}
#else
ACC_TYPE sums[WMITER * TM * WNITER * TN];
FLOAT_TYPE cache_a[WMITER * TM];
FLOAT_TYPE cache_b[TN];
FLOAT_TYPE_VEC2 cache_a[WMITER * TM];
FLOAT_TYPE_VEC2 cache_b[TN];
[[unroll]] for (uint i = 0; i < WMITER*TM*WNITER*TN; i++) {
sums[i] = ACC_TYPE(0.0f);
@@ -312,13 +312,13 @@ void main() {
for (uint block = start_k; block < end_k; block += BK) {
[[unroll]] for (uint l = 0; l < BM; l += loadstride_a) {
load_a_to_shmem(pos_a, loadr_a, loadc_a + l, ir * BM + loadc_a + l, block + loadr_a, end_k);
load_a_to_shmem(pos_a, loadr_a, loadc_a + l, ir * BM + loadc_a + l, block, end_k);
}
[[unroll]] for (uint l = 0; l < BN; l += loadstride_b) {
#if !defined(MUL_MAT_ID)
load_b_to_shmem(pos_b, loadr_b, loadc_b + l, ic * BN + loadc_b + l, block + loadr_b, end_k);
load_b_to_shmem(pos_b, loadr_b, loadc_b + l, ic * BN + loadc_b + l, block, end_k);
#else
load_b_to_shmem(pos_b, loadr_b, loadc_b + l, ic, _ne1, block + loadr_b, end_k);
load_b_to_shmem(pos_b, loadr_b, loadc_b + l, ic, _ne1, block, end_k);
#endif
}
@@ -331,17 +331,17 @@ void main() {
[[unroll]] for (uint i = 0; i < BK; i += TK) {
[[unroll]] for (uint cm_row = 0; cm_row < cms_per_row; cm_row++) {
// Load from shared into cache
coopMatLoad(cache_a, buf_a, (warp_r * WM + cm_row * TM) * SHMEM_STRIDE + i, SHMEM_STRIDE, gl_CooperativeMatrixLayoutRowMajor);
coopMatLoad(cache_a, buf_a, (warp_r * WM + cm_row * TM) * SHMEM_STRIDE + i / 2, SHMEM_STRIDE, gl_CooperativeMatrixLayoutRowMajor);
[[unroll]] for (uint cm_col = 0; cm_col < cms_per_col; cm_col++) {
coopMatLoad(cache_b, buf_b, (warp_c * WN + cm_col * TN) * SHMEM_STRIDE + i, SHMEM_STRIDE, gl_CooperativeMatrixLayoutColumnMajor);
coopMatLoad(cache_b, buf_b, (warp_c * WN + cm_col * TN) * SHMEM_STRIDE + i / 2, SHMEM_STRIDE, gl_CooperativeMatrixLayoutColumnMajor);
sums[cm_col * cms_per_row + cm_row] = coopMatMulAdd(cache_a, cache_b, sums[cm_col * cms_per_row + cm_row]);
}
}
}
#else
[[unroll]] for (uint i = 0; i < BK; i++) {
[[unroll]] for (uint i = 0; i < BK / 2; i++) {
// Load from shared into cache
[[unroll]] for (uint wsir = 0; wsir < WMITER; wsir++) {
[[unroll]] for (uint j = 0; j < TM; j++) {
@@ -357,7 +357,7 @@ void main() {
[[unroll]] for (uint cc = 0; cc < TN; cc++) {
[[unroll]] for (uint cr = 0; cr < TM; cr++) {
const uint sums_idx = (wsic * TN + cc) * (WMITER * TM) + wsir * TM + cr;
sums[sums_idx] = fma(ACC_TYPE(cache_a[wsir * TM + cr]), ACC_TYPE(cache_b[cc]), sums[sums_idx]);
sums[sums_idx] = fma(ACC_TYPE(cache_a[wsir * TM + cr].x), ACC_TYPE(cache_b[cc].x), fma(ACC_TYPE(cache_a[wsir * TM + cr].y), ACC_TYPE(cache_b[cc].y), sums[sums_idx]));
}
}
}