vulkan: use larger K step per iteration in mul_mat_vec.

Add vec4 dequantization functions, and use them to do K=8 per iteration in
mul_mat_vec. This uses 16b loads for the quant values and 128b loads for B
which helps reduce the load on the memory system.

The K_PER_ITER==2 logic is still there, just for F16/F32, and really only
because they support unaligned sizes.

Tweak the num_iters/unrolling logic to be simpler and catch a couple missed
unrolling opportunities.
This commit is contained in:
Jeff Bolz 2024-11-17 23:41:51 -06:00
parent 55f477b114
commit 57b2bf23cc
2 changed files with 108 additions and 10 deletions

View file

@ -29,6 +29,11 @@ vec2 dequantize(uint ib, uint iqs, uint a_offset) {
const uint vui = uint(data_a[a_offset + ib].qs[iqs]);
return (vec2(vui & 0xF, vui >> 4) - 8.0f) * d;
}
vec4 dequantize4(uint ib, uint iqs, uint a_offset) {
const float d = float(data_a_packed16[a_offset + ib].d);
const uint vui = uint(data_a_packed16[a_offset + ib].qs[iqs/2]);
return (vec4(vui & 0xF, (vui >> 4) & 0xF, (vui >> 8) & 0xF, (vui >> 12) & 0xF) - 8.0f) * d;
}
#endif
#if defined(DATA_A_Q4_1)
@ -38,6 +43,12 @@ vec2 dequantize(uint ib, uint iqs, uint a_offset) {
const uint vui = uint(data_a[a_offset + ib].qs[iqs]);
return vec2(vui & 0xF, vui >> 4) * d + m;
}
vec4 dequantize4(uint ib, uint iqs, uint a_offset) {
const float d = float(data_a_packed16[a_offset + ib].d);
const float m = float(data_a_packed16[a_offset + ib].m);
const uint vui = uint(data_a_packed16[a_offset + ib].qs[iqs/2]);
return vec4(vui & 0xF, (vui >> 4) & 0xF, (vui >> 8) & 0xF, (vui >> 12) & 0xF) * d + m;
}
#endif
#if defined(DATA_A_Q5_0)
@ -48,6 +59,14 @@ vec2 dequantize(uint ib, uint iqs, uint a_offset) {
const uint vui = uint(data_a[a_offset + ib].qs[iqs]);
return (vec2((vui & 0xF) | qh.x, (vui >> 4) | qh.y) - 16.0f) * d;
}
vec4 dequantize4(uint ib, uint iqs, uint a_offset) {
const float d = float(data_a_packed16[a_offset + ib].d);
const uint uint_qh = uint(data_a_packed16[a_offset + ib].qh[1]) << 16 | data_a_packed16[a_offset + ib].qh[0];
const ivec2 qh0 = ivec2(((uint_qh >> iqs) << 4) & 0x10, (uint_qh >> (iqs + 12)) & 0x10);
const ivec2 qh1 = ivec2(((uint_qh >> (iqs + 1)) << 4) & 0x10, (uint_qh >> (iqs + 13)) & 0x10);
const uint vui = uint(data_a_packed16[a_offset + ib].qs[iqs/2]);
return (vec4(((vui >> 0) & 0xF) | qh0.x, ((vui >> 4) & 0xF) | qh0.y, ((vui >> 8) & 0xF) | qh1.x, ((vui >> 12) & 0xF) | qh1.y) - 16.0f) * d;
}
#endif
#if defined(DATA_A_Q5_1)
@ -59,6 +78,15 @@ vec2 dequantize(uint ib, uint iqs, uint a_offset) {
const uint vui = uint(data_a[a_offset + ib].qs[iqs]);
return vec2((vui & 0xF) | qh.x, (vui >> 4) | qh.y) * d + m;
}
vec4 dequantize4(uint ib, uint iqs, uint a_offset) {
const float d = float(data_a_packed16[a_offset + ib].d);
const float m = float(data_a_packed16[a_offset + ib].m);
const uint uint_qh = data_a_packed16[a_offset + ib].qh;
const ivec2 qh0 = ivec2(((uint_qh >> iqs) << 4) & 0x10, (uint_qh >> (iqs + 12)) & 0x10);
const ivec2 qh1 = ivec2(((uint_qh >> (iqs + 1)) << 4) & 0x10, (uint_qh >> (iqs + 13)) & 0x10);
const uint vui = uint(data_a_packed16[a_offset + ib].qs[iqs/2]);
return vec4(((vui >> 0) & 0xF) | qh0.x, ((vui >> 4) & 0xF) | qh0.y, ((vui >> 8) & 0xF) | qh1.x, ((vui >> 12) & 0xF) | qh1.y) * d + m;
}
#endif
#if defined(DATA_A_Q8_0)
@ -66,6 +94,12 @@ vec2 dequantize(uint ib, uint iqs, uint a_offset) {
const float d = float(data_a[a_offset + ib].d);
return vec2(int(data_a[a_offset + ib].qs[iqs]), int(data_a[a_offset + ib].qs[iqs + 1])) * d;
}
vec4 dequantize4(uint ib, uint iqs, uint a_offset) {
const float d = float(data_a_packed16[a_offset + ib].d);
uint32_t v0 = data_a_packed16[a_offset + ib].qs[iqs/2];
uint32_t v1 = data_a_packed16[a_offset + ib].qs[iqs/2 + 1];
return vec4(int8_t(v0 & 0xFF), int8_t((v0 >> 8) & 0xFF), int8_t(v1 & 0xFF), int8_t((v1 >> 8) & 0xFF)) * d;
}
#endif
#if defined(DATA_A_IQ4_NL)
@ -74,4 +108,9 @@ vec2 dequantize(uint ib, uint iqs, uint a_offset) {
const uint vui = uint(data_a[a_offset + ib].qs[iqs]);
return vec2(kvalues_iq4nl[vui & 0xF], kvalues_iq4nl[vui >> 4]) * d;
}
vec4 dequantize4(uint ib, uint iqs, uint a_offset) {
const float d = float(data_a_packed16[a_offset + ib].d);
const uint vui = uint(data_a_packed16[a_offset + ib].qs[iqs/2]);
return vec4(kvalues_iq4nl[vui & 0xF], kvalues_iq4nl[(vui >> 4) & 0xF], kvalues_iq4nl[(vui >> 8) & 0xF], kvalues_iq4nl[(vui >> 12) & 0xF]) * d;
}
#endif

View file

@ -3,7 +3,7 @@
#ifdef FLOAT16
#extension GL_EXT_shader_explicit_arithmetic_types_float16 : require
#endif
#extension GL_EXT_shader_explicit_arithmetic_types_int32 : require
#extension GL_EXT_shader_explicit_arithmetic_types : require
#include "mul_mat_vec_base.comp"
@ -12,16 +12,48 @@ layout(local_size_x_id = 0, local_size_y = 1, local_size_z = 1) in;
layout (constant_id = 0) const uint BLOCK_SIZE = 32;
layout (constant_id = 1) const uint NUM_ROWS = 1;
#if !defined(DATA_A_F32) && !defined(DATA_A_F16)
#define K_PER_ITER 8
#else
#define K_PER_ITER 2
#endif
uint a_offset, b_offset, d_offset, y_offset;
shared FLOAT_TYPE tmpsh[NUM_ROWS][BLOCK_SIZE];
void iter(inout FLOAT_TYPE temp[NUM_ROWS], const uint first_row, const uint num_rows, const uint tid, const uint i, bool lastiter)
{
const uint col = i*BLOCK_SIZE + 2*tid;
const uint col = i*BLOCK_SIZE + K_PER_ITER*tid;
const uint iqs = (col%QUANT_K)/QUANT_R; // quant index
const uint iybs = col - col%QUANT_K; // y block start index
#if K_PER_ITER == 8
#if QUANT_R == 2
B_TYPE_VEC4 bv02 = data_b_v4[(b_offset + iybs + iqs) / 4];
B_TYPE_VEC4 bv13 = data_b_v4[(b_offset + iybs + iqs + y_offset) / 4];
FLOAT_TYPE b0 = FLOAT_TYPE(bv02.x);
FLOAT_TYPE b1 = FLOAT_TYPE(bv13.x);
FLOAT_TYPE b2 = FLOAT_TYPE(bv02.y);
FLOAT_TYPE b3 = FLOAT_TYPE(bv13.y);
FLOAT_TYPE b4 = FLOAT_TYPE(bv02.z);
FLOAT_TYPE b5 = FLOAT_TYPE(bv13.z);
FLOAT_TYPE b6 = FLOAT_TYPE(bv02.w);
FLOAT_TYPE b7 = FLOAT_TYPE(bv13.w);
#else
B_TYPE_VEC4 bv0 = data_b_v4[(b_offset + iybs + iqs) / 4];
B_TYPE_VEC4 bv1 = data_b_v4[(b_offset + iybs + iqs) / 4 + 1];
FLOAT_TYPE b0 = FLOAT_TYPE(bv0.x);
FLOAT_TYPE b1 = FLOAT_TYPE(bv0.y);
FLOAT_TYPE b2 = FLOAT_TYPE(bv0.z);
FLOAT_TYPE b3 = FLOAT_TYPE(bv0.w);
FLOAT_TYPE b4 = FLOAT_TYPE(bv1.x);
FLOAT_TYPE b5 = FLOAT_TYPE(bv1.y);
FLOAT_TYPE b6 = FLOAT_TYPE(bv1.z);
FLOAT_TYPE b7 = FLOAT_TYPE(bv1.w);
#endif
#else
// Check if the second of the pair of elements is OOB, and don't fetch B or
// accumulate it. We still fetch a pair of elements for A, which is fine for
// quantized formats since they'll be within the same block. We should
@ -34,9 +66,24 @@ void iter(inout FLOAT_TYPE temp[NUM_ROWS], const uint first_row, const uint num_
if (!OOB) {
b1 = FLOAT_TYPE(data_b[b_offset + iybs + iqs + y_offset]);
}
#endif
[[unroll]] for (uint n = 0; n < num_rows; ++n) {
const uint ib = ((first_row + n)*p.ncols + col)/QUANT_K; // block index
#if K_PER_ITER == 8
const vec4 v = dequantize4(ib, iqs, a_offset);
const vec4 v2 = dequantize4(ib, iqs+(4/QUANT_R), a_offset);
// matrix multiplication
temp[n] = fma(FLOAT_TYPE(v.x), b0, temp[n]);
temp[n] = fma(FLOAT_TYPE(v.y), b1, temp[n]);
temp[n] = fma(FLOAT_TYPE(v.z), b2, temp[n]);
temp[n] = fma(FLOAT_TYPE(v.w), b3, temp[n]);
temp[n] = fma(FLOAT_TYPE(v2.x), b4, temp[n]);
temp[n] = fma(FLOAT_TYPE(v2.y), b5, temp[n]);
temp[n] = fma(FLOAT_TYPE(v2.z), b6, temp[n]);
temp[n] = fma(FLOAT_TYPE(v2.w), b7, temp[n]);
#else
const vec2 v = dequantize(ib, iqs, a_offset);
// matrix multiplication
@ -44,6 +91,7 @@ void iter(inout FLOAT_TYPE temp[NUM_ROWS], const uint first_row, const uint num_
if (!OOB) {
temp[n] = fma(FLOAT_TYPE(v.y), b1, temp[n]);
}
#endif
}
}
@ -61,22 +109,33 @@ void compute_outputs(const uint32_t first_row, const uint32_t num_rows) {
temp[i] = FLOAT_TYPE(0);
}
const int unroll_count = 8;
const uint num_iters = (p.ncols >= 2*tid) ? ((p.ncols - 2*tid + BLOCK_SIZE - 1) / BLOCK_SIZE) : 0;
const uint unrolled_iters = num_iters & ~(2*unroll_count - 1);
uint num_iters = p.ncols / (K_PER_ITER * BLOCK_SIZE);
if (num_iters * K_PER_ITER * BLOCK_SIZE + K_PER_ITER*tid < p.ncols) {
num_iters++;
}
int unroll_count = 4;
uint unrolled_iters = num_iters & ~(unroll_count - 1);
uint i = 0;
while (i < unrolled_iters) {
// Manually partially unroll the loop
[[unroll]] for (uint k = 0; k < unroll_count; ++k) {
iter(temp, first_row, num_rows, tid, i, false);
i += 2;
iter(temp, first_row, num_rows, tid, i*K_PER_ITER, false);
i++;
}
}
unroll_count = 2;
unrolled_iters = num_iters & ~(unroll_count - 1);
while (i < unrolled_iters) {
// Manually partially unroll the loop
[[unroll]] for (uint k = 0; k < unroll_count; ++k) {
iter(temp, first_row, num_rows, tid, i*K_PER_ITER, false);
i++;
}
}
while (i < num_iters) {
iter(temp, first_row, num_rows, tid, i, true);
i += 2;
iter(temp, first_row, num_rows, tid, i*K_PER_ITER, true);
i++;
}
// sum up partial sums and write back result