arm64: optimize q6_k_q8_k kernel with i8mm (llama/13519)

This PR improves q6_k_q8_k gemm kernel with arm64 i8mm instruction.

Tested on neoverse-n2 with llama3 8b q6_k quantization model.
- 40% ~ 54% S_PP uplift for all batch sizes
- 16% ~ 47% S_TG uplift for batch size 4 and above

Perplexity doesn't change with this PR.

```
// tested on neoverse-n2
$ llama-batched-bench \
      -m Meta-Llama-3-8B-Instruct-Q6_K.gguf \
      --no-mmap -fa \
      -c 8192 -b 4096 -ub 512 -npp 128 -ntg 128 \
      -npl 1,2,4,8,16,32 \
      -t 64

---------------------------------------------------------------------
|    PP |     TG |    B |       S_PP t/s      |       S_TG t/s      |
|       |        |      | original |  this pr | original |  this pr |
|-------|--------|------|----------|----------|----------|----------|
|   128 |    128 |    1 |    78.52 |   109.18 |    18.63 |    18.88 |
|   128 |    128 |    2 |    84.62 |   123.94 |    34.54 |    36.92 |
|   128 |    128 |    4 |    84.36 |   122.49 |    52.65 |    61.32 |
|   128 |    128 |    8 |    90.52 |   138.87 |    63.46 |    84.41 |
|   128 |    128 |   16 |    90.11 |   138.56 |    71.04 |   101.33 |
|   128 |    128 |   32 |    89.81 |   137.79 |    75.14 |   110.47 |
---------------------------------------------------------------------
```
This commit is contained in:
Yibo Cai 2025-05-15 03:53:52 +08:00 committed by Georgi Gerganov
parent 0dda27bc0b
commit 8e9bf548f4
2 changed files with 199 additions and 0 deletions

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@ -8519,7 +8519,11 @@ void ggml_vec_dot_q5_K_q8_K(int n, float * GGML_RESTRICT s, size_t bs, const voi
void ggml_vec_dot_q6_K_q8_K(int n, float * GGML_RESTRICT s, size_t bs, const void * GGML_RESTRICT vx, size_t bx, const void * GGML_RESTRICT vy, size_t by, int nrc) { void ggml_vec_dot_q6_K_q8_K(int n, float * GGML_RESTRICT s, size_t bs, const void * GGML_RESTRICT vx, size_t bx, const void * GGML_RESTRICT vy, size_t by, int nrc) {
assert(n % QK_K == 0); assert(n % QK_K == 0);
#ifdef __ARM_FEATURE_MATMUL_INT8
assert((nrc == 2) || (nrc == 1));
#else
assert(nrc == 1); assert(nrc == 1);
#endif
UNUSED(nrc); UNUSED(nrc);
UNUSED(bx); UNUSED(bx);
UNUSED(by); UNUSED(by);
@ -8530,6 +8534,197 @@ void ggml_vec_dot_q6_K_q8_K(int n, float * GGML_RESTRICT s, size_t bs, const voi
const int nb = n / QK_K; const int nb = n / QK_K;
#if defined(__ARM_FEATURE_MATMUL_INT8)
if (nrc == 2) {
const block_q6_K * GGML_RESTRICT x0 = x;
const block_q6_K * GGML_RESTRICT x1 = (const block_q6_K *) ((const uint8_t *)vx + bx);
const block_q8_K * GGML_RESTRICT y0 = y;
const block_q8_K * GGML_RESTRICT y1 = (const block_q8_K *) ((const uint8_t *)vy + by);
float32x4_t vfsum = vdupq_n_f32(0.0f);
for (int i = 0; i < nb; ++i, ++x0, ++x1, ++y0, ++y1) {
const uint8_t * GGML_RESTRICT ql0 = x0->ql;
const uint8_t * GGML_RESTRICT ql1 = x1->ql;
const uint8_t * GGML_RESTRICT qh0 = x0->qh;
const uint8_t * GGML_RESTRICT qh1 = x1->qh;
const int8_t * GGML_RESTRICT qy0 = y0->qs;
const int8_t * GGML_RESTRICT qy1 = y1->qs;
const uint8x16_t mone = vdupq_n_u8(0x30);
const uint8x16_t m4b = vdupq_n_u8(0x0f);
int32x4_t visum = vdupq_n_s32(0);
// process 8 blocks per iteration, totally 16 blocks
for (int j = 0; j < 2; ++j, qh0 += 32, ql0 += 64, qh1 += 32, ql1 += 64) {
int8x16_t vx0[8], vx1[8];
// de-quantize vx0[8]
{
const uint8x16x2_t qh_bits = vld1q_u8_x2(qh0);
const uint8x16x4_t ql_bits = vld1q_u8_x4(ql0);
uint8x16_t q6h_0 = vandq_u8(mone, vshlq_n_u8(qh_bits.val[0], 4));
uint8x16_t q6h_1 = vandq_u8(mone, vshlq_n_u8(qh_bits.val[1], 4));
uint8x16_t q6h_2 = vandq_u8(mone, vshlq_n_u8(qh_bits.val[0], 2));
uint8x16_t q6h_3 = vandq_u8(mone, vshlq_n_u8(qh_bits.val[1], 2));
vx0[0] = vreinterpretq_s8_u8(vorrq_u8(vandq_u8(ql_bits.val[0], m4b), q6h_0));
vx0[1] = vreinterpretq_s8_u8(vorrq_u8(vandq_u8(ql_bits.val[1], m4b), q6h_1));
vx0[2] = vreinterpretq_s8_u8(vorrq_u8(vandq_u8(ql_bits.val[2], m4b), q6h_2));
vx0[3] = vreinterpretq_s8_u8(vorrq_u8(vandq_u8(ql_bits.val[3], m4b), q6h_3));
q6h_0 = vandq_u8(mone, qh_bits.val[0]);
q6h_1 = vandq_u8(mone, qh_bits.val[1]);
q6h_2 = vandq_u8(mone, vshrq_n_u8(qh_bits.val[0], 2));
q6h_3 = vandq_u8(mone, vshrq_n_u8(qh_bits.val[1], 2));
vx0[4] = vreinterpretq_s8_u8(vorrq_u8(vshrq_n_u8(ql_bits.val[0], 4), q6h_0));
vx0[5] = vreinterpretq_s8_u8(vorrq_u8(vshrq_n_u8(ql_bits.val[1], 4), q6h_1));
vx0[6] = vreinterpretq_s8_u8(vorrq_u8(vshrq_n_u8(ql_bits.val[2], 4), q6h_2));
vx0[7] = vreinterpretq_s8_u8(vorrq_u8(vshrq_n_u8(ql_bits.val[3], 4), q6h_3));
}
// de-quantize vx1[8]
{
const uint8x16x2_t qh_bits = vld1q_u8_x2(qh1);
const uint8x16x4_t ql_bits = vld1q_u8_x4(ql1);
uint8x16_t q6h_0 = vandq_u8(mone, vshlq_n_u8(qh_bits.val[0], 4));
uint8x16_t q6h_1 = vandq_u8(mone, vshlq_n_u8(qh_bits.val[1], 4));
uint8x16_t q6h_2 = vandq_u8(mone, vshlq_n_u8(qh_bits.val[0], 2));
uint8x16_t q6h_3 = vandq_u8(mone, vshlq_n_u8(qh_bits.val[1], 2));
vx1[0] = vreinterpretq_s8_u8(vorrq_u8(vandq_u8(ql_bits.val[0], m4b), q6h_0));
vx1[1] = vreinterpretq_s8_u8(vorrq_u8(vandq_u8(ql_bits.val[1], m4b), q6h_1));
vx1[2] = vreinterpretq_s8_u8(vorrq_u8(vandq_u8(ql_bits.val[2], m4b), q6h_2));
vx1[3] = vreinterpretq_s8_u8(vorrq_u8(vandq_u8(ql_bits.val[3], m4b), q6h_3));
q6h_0 = vandq_u8(mone, qh_bits.val[0]);
q6h_1 = vandq_u8(mone, qh_bits.val[1]);
q6h_2 = vandq_u8(mone, vshrq_n_u8(qh_bits.val[0], 2));
q6h_3 = vandq_u8(mone, vshrq_n_u8(qh_bits.val[1], 2));
vx1[4] = vreinterpretq_s8_u8(vorrq_u8(vshrq_n_u8(ql_bits.val[0], 4), q6h_0));
vx1[5] = vreinterpretq_s8_u8(vorrq_u8(vshrq_n_u8(ql_bits.val[1], 4), q6h_1));
vx1[6] = vreinterpretq_s8_u8(vorrq_u8(vshrq_n_u8(ql_bits.val[2], 4), q6h_2));
vx1[7] = vreinterpretq_s8_u8(vorrq_u8(vshrq_n_u8(ql_bits.val[3], 4), q6h_3));
}
// process 16 elements (one block with same scale) per iteration
// - vx = concat(ql, qh) - 32
// - r1,r2,r3,r4 = smmla(vx, vy)
for (int k = 0; k < 8; ++k) {
const int blk = j * 8 + k;
const int8x16_t vy0 = vld1q_s8(qy0);
const int8x16_t vy1 = vld1q_s8(qy1);
qy0 += 16;
qy1 += 16;
const int32x4_t block_scale = {
x0->scales[blk],
x0->scales[blk],
x1->scales[blk],
x1->scales[blk],
};
// calculate four results at once with outer product
const int8x16_t vx_l = vreinterpretq_s8_s64(vzip1q_s64(vreinterpretq_s64_s8(vx0[k]), vreinterpretq_s64_s8(vx1[k])));
const int8x16_t vx_h = vreinterpretq_s8_s64(vzip2q_s64(vreinterpretq_s64_s8(vx0[k]), vreinterpretq_s64_s8(vx1[k])));
const int8x16_t vy_l = vreinterpretq_s8_s64(vzip1q_s64(vreinterpretq_s64_s8(vy0), vreinterpretq_s64_s8(vy1)));
const int8x16_t vy_h = vreinterpretq_s8_s64(vzip2q_s64(vreinterpretq_s64_s8(vy0), vreinterpretq_s64_s8(vy1)));
int32x4_t vr = vdupq_n_s32(0);
vr = vmmlaq_s32(vr, vx_l, vy_l);
vr = vmmlaq_s32(vr, vx_h, vy_h);
// apply block scale, will NOT overflow
// block_scale * sum_256(int6*int8) <= 2^(8+8+6+8) = 30 bits
visum = vmlaq_s32(visum, vr, block_scale);
}
}
// adjust bias, apply superblock scale
{
int32_t bias[4];
#ifdef __ARM_FEATURE_SVE
const svbool_t pg16_8 = svptrue_pat_b16(SV_VL8);
const svbool_t pg8_8 = svptrue_pat_b8(SV_VL8);
const svint16_t y0_q8sums_0 = svld1_s16(pg16_8, y0->bsums);
const svint16_t y0_q8sums_1 = svld1_s16(pg16_8, y0->bsums + 8);
const svint16_t y1_q8sums_0 = svld1_s16(pg16_8, y1->bsums);
const svint16_t y1_q8sums_1 = svld1_s16(pg16_8, y1->bsums + 8);
const svint16_t x0_q6scales_0 = svunpklo_s16(svld1_s8(pg8_8, x0->scales));
const svint16_t x0_q6scales_1 = svunpklo_s16(svld1_s8(pg8_8, x0->scales + 8));
const svint16_t x1_q6scales_0 = svunpklo_s16(svld1_s8(pg8_8, x1->scales));
const svint16_t x1_q6scales_1 = svunpklo_s16(svld1_s8(pg8_8, x1->scales + 8));
const svint64_t zero = svdup_n_s64(0);
bias[0] = svaddv_s64(svptrue_b64(), svadd_s64_x(svptrue_b64(), svdot_s64(zero, y0_q8sums_0, x0_q6scales_0),
svdot_s64(zero, y0_q8sums_1, x0_q6scales_1)));
bias[1] = svaddv_s64(svptrue_b64(), svadd_s64_x(svptrue_b64(), svdot_s64(zero, y1_q8sums_0, x0_q6scales_0),
svdot_s64(zero, y1_q8sums_1, x0_q6scales_1)));
bias[2] = svaddv_s64(svptrue_b64(), svadd_s64_x(svptrue_b64(), svdot_s64(zero, y0_q8sums_0, x1_q6scales_0),
svdot_s64(zero, y0_q8sums_1, x1_q6scales_1)));
bias[3] = svaddv_s64(svptrue_b64(), svadd_s64_x(svptrue_b64(), svdot_s64(zero, y1_q8sums_0, x1_q6scales_0),
svdot_s64(zero, y1_q8sums_1, x1_q6scales_1)));
#else
// NEON doesn't support int16 dot product, fallback to separated mul and add
const int16x8x2_t q8sums0 = vld1q_s16_x2(y0->bsums);
const int16x8x2_t q8sums1 = vld1q_s16_x2(y1->bsums);
int8x16_t scales_s8 = vld1q_s8(x0->scales);
const int16x8x2_t q6scales0 = {{vmovl_s8(vget_low_s8(scales_s8)), vmovl_s8(vget_high_s8(scales_s8))}};
scales_s8 = vld1q_s8(x1->scales);
const int16x8x2_t q6scales1 = {{vmovl_s8(vget_low_s8(scales_s8)), vmovl_s8(vget_high_s8(scales_s8))}};
int32x4_t prod;
prod = vaddq_s32(vaddq_s32(vmull_s16(vget_low_s16 (q8sums0.val[0]), vget_low_s16 (q6scales0.val[0])),
vmull_s16(vget_high_s16(q8sums0.val[0]), vget_high_s16(q6scales0.val[0]))),
vaddq_s32(vmull_s16(vget_low_s16 (q8sums0.val[1]), vget_low_s16 (q6scales0.val[1])),
vmull_s16(vget_high_s16(q8sums0.val[1]), vget_high_s16(q6scales0.val[1]))));
bias[0] = vaddvq_s32(prod);
prod = vaddq_s32(vaddq_s32(vmull_s16(vget_low_s16 (q8sums1.val[0]), vget_low_s16 (q6scales0.val[0])),
vmull_s16(vget_high_s16(q8sums1.val[0]), vget_high_s16(q6scales0.val[0]))),
vaddq_s32(vmull_s16(vget_low_s16 (q8sums1.val[1]), vget_low_s16 (q6scales0.val[1])),
vmull_s16(vget_high_s16(q8sums1.val[1]), vget_high_s16(q6scales0.val[1]))));
bias[1] = vaddvq_s32(prod);
prod = vaddq_s32(vaddq_s32(vmull_s16(vget_low_s16 (q8sums0.val[0]), vget_low_s16 (q6scales1.val[0])),
vmull_s16(vget_high_s16(q8sums0.val[0]), vget_high_s16(q6scales1.val[0]))),
vaddq_s32(vmull_s16(vget_low_s16 (q8sums0.val[1]), vget_low_s16 (q6scales1.val[1])),
vmull_s16(vget_high_s16(q8sums0.val[1]), vget_high_s16(q6scales1.val[1]))));
bias[2] = vaddvq_s32(prod);
prod = vaddq_s32(vaddq_s32(vmull_s16(vget_low_s16 (q8sums1.val[0]), vget_low_s16 (q6scales1.val[0])),
vmull_s16(vget_high_s16(q8sums1.val[0]), vget_high_s16(q6scales1.val[0]))),
vaddq_s32(vmull_s16(vget_low_s16 (q8sums1.val[1]), vget_low_s16 (q6scales1.val[1])),
vmull_s16(vget_high_s16(q8sums1.val[1]), vget_high_s16(q6scales1.val[1]))));
bias[3] = vaddvq_s32(prod);
#endif
const int32x4_t vibias = vmulq_n_s32(vld1q_s32(bias), 32);
const float32x4_t superblock_scale = {
GGML_FP16_TO_FP32(x0->d) * y0->d,
GGML_FP16_TO_FP32(x0->d) * y1->d,
GGML_FP16_TO_FP32(x1->d) * y0->d,
GGML_FP16_TO_FP32(x1->d) * y1->d,
};
visum = vsubq_s32(visum, vibias);
vfsum = vmlaq_f32(vfsum, vcvtq_f32_s32(visum), superblock_scale);
}
}
// vfsum = ABCD -> ACBD
// AC -> s, BD -> (s+bs)
vfsum = vzip1q_f32(vfsum, vextq_f32(vfsum, vfsum, 2));
vst1_f32(s, vget_low_f32 (vfsum));
vst1_f32(s + bs, vget_high_f32(vfsum));
return;
}
#endif
#ifdef __ARM_FEATURE_SVE #ifdef __ARM_FEATURE_SVE
const int vector_length = ggml_cpu_get_sve_cnt()*8; const int vector_length = ggml_cpu_get_sve_cnt()*8;
float sum = 0; float sum = 0;

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@ -282,7 +282,11 @@ static const struct ggml_type_traits_cpu type_traits_cpu[GGML_TYPE_COUNT] = {
.from_float = quantize_row_q6_K, .from_float = quantize_row_q6_K,
.vec_dot = ggml_vec_dot_q6_K_q8_K, .vec_dot = ggml_vec_dot_q6_K_q8_K,
.vec_dot_type = GGML_TYPE_Q8_K, .vec_dot_type = GGML_TYPE_Q8_K,
#if defined (__ARM_FEATURE_MATMUL_INT8)
.nrows = 2,
#else
.nrows = 1, .nrows = 1,
#endif
}, },
[GGML_TYPE_IQ2_XXS] = { [GGML_TYPE_IQ2_XXS] = {
.from_float = NULL, .from_float = NULL,