wip : 8 rows per simd group

This commit is contained in:
Georgi Gerganov 2024-01-21 12:23:22 +02:00
parent b97325800a
commit 8cde449b8b
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GPG Key ID: 449E073F9DC10735
2 changed files with 140 additions and 45 deletions

View File

@ -2252,14 +2252,14 @@ static bool ggml_metal_graph_compute(
[encoder setBytes:&ne3 length:sizeof( int64_t) atIndex:26];
[encoder setBytes:&scale length:sizeof( float) atIndex:27];
const int nwarps = 1;
const int64_t nwarps = 2;
const size_t shalf = sizeof(float)/2;
const size_t smem = nwarps*(2*8*nwarps*ne00 + 128)*(sizeof(float)/2);
GGML_ASSERT(2*32*nwarps*ne00*shalf <= ctx->device.maxThreadgroupMemoryLength);
[encoder setThreadgroupMemoryLength:2*32*nwarps*ne00*shalf atIndex:0];
GGML_ASSERT(smem <= ctx->device.maxThreadgroupMemoryLength);
[encoder setThreadgroupMemoryLength:smem atIndex:0];
[encoder dispatchThreadgroups:MTLSizeMake((ne01 + 31)/32, ne02, ne03) threadsPerThreadgroup:MTLSizeMake(32, 1, 1)];
[encoder dispatchThreadgroups:MTLSizeMake(ne01, (ne02 + 8*nwarps - 1)/(8*nwarps), ne03) threadsPerThreadgroup:MTLSizeMake(32*nwarps, 1, 1)];
} break;
case GGML_OP_DUP:
case GGML_OP_CPY:

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@ -2031,33 +2031,20 @@ kernel void kernel_flash_attn_ext_f16(
uint3 ntg[[threads_per_threadgroup]],
uint tiisg[[thread_index_in_simdgroup]],
uint sgitg[[simdgroup_index_in_threadgroup]]) {
const int64_t iq3 = tgpig[2];
const int64_t iq2 = tgpig[1];
const int64_t iq1 = tgpig[0]*N_SIMDWIDTH + tiisg;
//const int64_t iq3 = tgpig[2];
//const int64_t iq2 = tgpig[1];
//const int64_t iq1 = tgpig[0]*N_SIMDWIDTH + tiisg;
if (iq1 >= ne01) {
const uint nsg = ntg.x/N_SIMDWIDTH; // number of simdgroups
const int64_t iq3 = tgpig[2];
const int64_t iq2 = tgpig[1]*(8*nsg) + 8*sgitg + tiisg/4;
const int64_t iq1 = tgpig[0];
if (iq2 >= ne02) {
return;
}
const int64_t D4 = D/4;
// TODO: can we move this to the stack?
threadgroup half4 * V16 = (threadgroup half4 *) (shared + (2*sgitg*N_SIMDWIDTH + tiisg)*D);
// initialize with zeros
for (int64_t d = 0; d < D4; ++d) {
V16[d] = 0.0h;
}
threadgroup half4 * pq4 = (threadgroup half4 *) (shared + (2*sgitg*N_SIMDWIDTH + N_SIMDWIDTH)*D + tiisg*D);
half S = 0.0h;
half M = -INFINITY;
const int64_t ir = iq3*ne02*ne01 + iq2*ne01 + iq1;
device const float * mp = mask ? (device const float *) (mask + (ir%ne31)*nb31) : nullptr;
// assume K and V are same shape
const int64_t ne22 = ne12;
const int64_t ne23 = ne13;
@ -2081,11 +2068,97 @@ kernel void kernel_flash_attn_ext_f16(
const int64_t iv2 = iq2 / rv2;
const int64_t iv3 = iq3 / rv3;
// load Q to shared memory
for (int64_t d = 0; d < D4; ++d) {
pq4[d] = ((device const half4 *) ((device const char *) q + (iq1*nb01 + iq2*nb02 + iq3*nb03)))[d];
const int64_t ir = iq3*ne02*ne01 + iq2*ne01 + iq1;
device const float * mp = mask ? (device const float *) (mask + (ir%ne31)*nb31) : nullptr;
// const int64_t D4 = D/4;
//
// // TODO: can we move this to the stack?
// threadgroup half4x4 * V16 = (threadgroup half4x4 *) (shared);
//
// // initialize with zeros
// for (int64_t d = 0; d < D4; ++d) {
//
// }
//
// threadgroup half4 * pq4 = (threadgroup half4 *) (shared + 4*D);
//
// // load Q to shared memory
// for (int64_t d = 0; d < D4; ++d) {
// pq4[d] = ((device const half4 *) ((device const char *) q + (iq1*nb01 + iq2*nb02 + iq3*nb03)))[d];
// }
//
// half S = 0.0h;
// half M = -INFINITY;
//
// for (int64_t ic = 0; ic < ne11; ++ic) {
// const half mv = mp ? mp[ic] : 0.0h;
// if (mv == -INFINITY) {
// continue;
// }
//
// device const half4 * pk4 = (device const half4 *) ((device char *) k + (ic*nb11 + ik2*nb12 + ik3*nb13));
// device const half4 * pv4 = (device const half4 *) ((device char *) v + (ic*nb21 + iv2*nb22 + iv3*nb23));
//
// half4 s4 = 0.0h;
//
// for (int64_t d = 0; d < D4; ++d) {
// s4 += pk4[d] * pq4[d];
// }
//
// half s = (s4.x + s4.y + s4.z + s4.w)*scale + mv;
//
// const half Mold = M;
//
// M = max(M, s);
//
// const half ms = exp(Mold - M);
// const half vs = exp(s - M);
//
// for (int64_t d = 0; d < D4; ++d) {
// V16[d] = V16[d]*ms + pv4[d]*vs;
// }
//
// S = S*ms + vs;
// }
//
// for (int64_t d = 0; d < D4; ++d) {
// V16[d] /= S;
// }
//
// // dst indices
// const int64_t i1 = iq1;
// const int64_t i2 = iq2;
// const int64_t i3 = iq3;
//
// device float4 * dst4 = (device float4 *) dst;
//
// for (int64_t d = 0; d < D4; ++d) {
// dst4[(i3*ne2*ne1 + i2 + i1*ne1)*D4 + d] = (float4) V16[d];
// }
const int64_t D4 = D/4;
threadgroup half4 * pq4 = (threadgroup half4 *) (shared + sgitg*(16*D + 128) );
threadgroup half4 * ps4 = (threadgroup half4 *) (shared + sgitg*(16*D + 128) + 8*D);
threadgroup half4 * ss4 = (threadgroup half4 *) (shared + sgitg*(16*D + 128) + 16*D);
threadgroup half * ss = (threadgroup half *) (shared + sgitg*(16*D + 128) + 16*D);
const uint tiih = tiisg%4; // thread index in head
const uint hiisg = tiisg/4; // head index in simdgroup
// load 8 heads from Q to shared memory
for (int64_t i = 0; i < D4/4; ++i) {
pq4[hiisg*D4 + 4*i + tiih] = ((device const half4 *) ((device const char *) q + (iq1*nb01 + iq2*nb02 + iq3*nb03)))[4*i + tiih];
ps4[hiisg*D4 + 4*i + tiih] = 0.0h;
}
simdgroup_barrier(mem_flags::mem_threadgroup);
half S = 0.0h;
half M = -INFINITY;
for (int64_t ic = 0; ic < ne11; ++ic) {
const half mv = mp ? mp[ic] : 0.0h;
if (mv == -INFINITY) {
@ -2097,10 +2170,17 @@ kernel void kernel_flash_attn_ext_f16(
half4 s4 = 0.0h;
for (int64_t d = 0; d < D4; ++d) {
s4 += pk4[d] * pq4[d];
for (int64_t i = 0; i < D4/4; ++i) {
s4 += pk4[4*i + tiih] * pq4[hiisg*D4 + 4*i + tiih];
}
ss4[hiisg*4 + tiih] = s4;
simdgroup_barrier(mem_flags::mem_threadgroup);
if (tiih == 0) {
s4 = ss4[4*hiisg + 0] + ss4[4*hiisg + 1] + ss4[4*hiisg + 2] + ss4[4*hiisg + 3];
half s = (s4.x + s4.y + s4.z + s4.w)*scale + mv;
const half Mold = M;
@ -2110,16 +2190,31 @@ kernel void kernel_flash_attn_ext_f16(
const half ms = exp(Mold - M);
const half vs = exp(s - M);
for (int64_t d = 0; d < D4; ++d) {
V16[d] = V16[d]*ms + pv4[d]*vs;
}
S = S*ms + vs;
ss[2*hiisg + 0] = ms;
ss[2*hiisg + 1] = vs;
}
for (int64_t d = 0; d < D4; ++d) {
V16[d] /= S;
simdgroup_barrier(mem_flags::mem_threadgroup);
const half ms = ss[2*hiisg + 0];
const half vs = ss[2*hiisg + 1];
for (int64_t i = 0; i < D4/4; ++i) {
ps4[hiisg*D4 + 4*i + tiih] = ps4[hiisg*D4 + 4*i + tiih]*ms + pv4[4*i + tiih]*vs;
}
}
simdgroup_barrier(mem_flags::mem_threadgroup);
if (tiih == 0) {
for (int64_t i = 0; i < D4; ++i) {
ps4[hiisg*D4 + i] /= S;
}
}
simdgroup_barrier(mem_flags::mem_threadgroup);
// dst indices
const int64_t i1 = iq1;
@ -2128,8 +2223,8 @@ kernel void kernel_flash_attn_ext_f16(
device float4 * dst4 = (device float4 *) dst;
for (int64_t d = 0; d < D4; ++d) {
dst4[(i3*ne2*ne1 + i2 + i1*ne1)*D4 + d] = (float4) V16[d];
for (int64_t i = 0; i < D4/4; ++i) {
dst4[(i3*ne2*ne1 + i2 + i1*ne1)*D4 + 4*i + tiih] = (float4) ps4[hiisg*D4 + 4*i + tiih];
}
}