ggml: aarch64: implement smmla kernel for q4_0_q8_0 quantized gemm

armv8.2-a and above supports MMLA instructions that have higher
throughput than DOT. this commit adds mmla kernel for
q4_0_q8_0 gemm. The feature is enabled if the platform supports
"__ARM_FEATURE_MATMUL_INT8"

On AWS Graviton3 processors this kernel resulted up to 1.5x
improvement for prompt evaluation throughput compared to the
default sdot kernel.
This commit is contained in:
Sunita Nadampalli 2024-02-08 15:15:02 +00:00
parent 52489546fb
commit ba668572ce
2 changed files with 76 additions and 4 deletions

View file

@ -3673,15 +3673,83 @@ void ggml_vec_dot_q4_0_q8_0(int n, float * restrict s, size_t bs, const void * r
const int nb = n / qk;
assert(n % qk == 0);
#if defined(__ARM_FEATURE_MATMUL_INT8)
assert((nrc == 2) || (nrc == 1));
#else
assert(nrc == 1);
UNUSED(nrc);
UNUSED(bx);
UNUSED(by);
UNUSED(bs);
#endif
const block_q4_0 * restrict x = vx;
const block_q8_0 * restrict y = vy;
#if defined(__ARM_FEATURE_MATMUL_INT8)
if (nrc == 2) {
const block_q4_0 * restrict vx0 = vx;
const block_q4_0 * restrict vx1 = vx + bx;
const block_q8_0 * restrict vy0 = vy;
const block_q8_0 * restrict vy1 = vy + by;
float32x4_t sumv0 = vdupq_n_f32(0.0f);
for (int i = 0; i < nb; i++) {
const block_q4_0 * restrict b_x0 = &vx0[i];
const block_q4_0 * restrict b_x1 = &vx1[i];
const block_q8_0 * restrict b_y0 = &vy0[i];
const block_q8_0 * restrict b_y1 = &vy1[i];
const uint8x16_t m4b = vdupq_n_u8(0x0F);
const int8x16_t s8b = vdupq_n_s8(0x8);
const uint8x16_t v0_0 = vld1q_u8(b_x0->qs);
const uint8x16_t v0_1 = vld1q_u8(b_x1->qs);
// 4-bit -> 8-bit
const int8x16_t v0_0l = vreinterpretq_s8_u8(vandq_u8 (v0_0, m4b));
const int8x16_t v0_0h = vreinterpretq_s8_u8(vshrq_n_u8(v0_0, 4));
const int8x16_t v0_1l = vreinterpretq_s8_u8(vandq_u8 (v0_1, m4b));
const int8x16_t v0_1h = vreinterpretq_s8_u8(vshrq_n_u8(v0_1, 4));
// sub 8
const int8x16_t x0_l = vsubq_s8(v0_0l, s8b);
const int8x16_t x0_h = vsubq_s8(v0_0h, s8b);
const int8x16_t x1_l = vsubq_s8(v0_1l, s8b);
const int8x16_t x1_h = vsubq_s8(v0_1h, s8b);
// load y
const int8x16_t y0_l = vld1q_s8(b_y0->qs);
const int8x16_t y0_h = vld1q_s8(b_y0->qs + 16);
const int8x16_t y1_l = vld1q_s8(b_y1->qs);
const int8x16_t y1_h = vld1q_s8(b_y1->qs + 16);
float32x4_t scale = {GGML_FP16_TO_FP32(b_x0->d)*GGML_FP16_TO_FP32(b_y0->d),
GGML_FP16_TO_FP32(b_x0->d)*GGML_FP16_TO_FP32(b_y1->d),
GGML_FP16_TO_FP32(b_x1->d)*GGML_FP16_TO_FP32(b_y0->d),
GGML_FP16_TO_FP32(b_x1->d)*GGML_FP16_TO_FP32(b_y1->d)};
int8x16_t l0 = vreinterpretq_s8_s64(vzip1q_s64(vreinterpretq_s64_s8(x0_l), vreinterpretq_s64_s8(x1_l)));
int8x16_t l1 = vreinterpretq_s8_s64(vzip2q_s64(vreinterpretq_s64_s8(x0_l), vreinterpretq_s64_s8(x1_l)));
int8x16_t l2 = vreinterpretq_s8_s64(vzip1q_s64(vreinterpretq_s64_s8(x0_h), vreinterpretq_s64_s8(x1_h)));
int8x16_t l3 = vreinterpretq_s8_s64(vzip2q_s64(vreinterpretq_s64_s8(x0_h), vreinterpretq_s64_s8(x1_h)));
int8x16_t r0 = vreinterpretq_s8_s64(vzip1q_s64(vreinterpretq_s64_s8(y0_l), vreinterpretq_s64_s8(y1_l)));
int8x16_t r1 = vreinterpretq_s8_s64(vzip2q_s64(vreinterpretq_s64_s8(y0_l), vreinterpretq_s64_s8(y1_l)));
int8x16_t r2 = vreinterpretq_s8_s64(vzip1q_s64(vreinterpretq_s64_s8(y0_h), vreinterpretq_s64_s8(y1_h)));
int8x16_t r3 = vreinterpretq_s8_s64(vzip2q_s64(vreinterpretq_s64_s8(y0_h), vreinterpretq_s64_s8(y1_h)));
sumv0 = vmlaq_f32(sumv0,(vcvtq_f32_s32(vmmlaq_s32((vmmlaq_s32((vmmlaq_s32((vmmlaq_s32(vdupq_n_s32(0), l0, r0)),
l1, r1)), l2, r2)), l3, r3))), scale);
}
float32x4_t sumv1 = vextq_f32(sumv0, sumv0, 2);
float32x4_t sumv2 = vzip1q_f32(sumv0, sumv1);
vst1_f32(s, vget_low_f32(sumv2));
vst1_f32(s + bs, vget_high_f32(sumv2));
return;
}
#endif
#if defined(__ARM_NEON)
float32x4_t sumv0 = vdupq_n_f32(0.0f);
float32x4_t sumv1 = vdupq_n_f32(0.0f);

4
ggml.c
View file

@ -481,7 +481,11 @@ static const ggml_type_traits_t type_traits[GGML_TYPE_COUNT] = {
.from_float_reference = (ggml_from_float_t) quantize_row_q4_0_reference,
.vec_dot = ggml_vec_dot_q4_0_q8_0,
.vec_dot_type = GGML_TYPE_Q8_0,
#if defined (__ARM_FEATURE_MATMUL_INT8)
.nrows = 2,
#else
.nrows = 1,
#endif
},
[GGML_TYPE_Q4_1] = {
.type_name = "q4_1",