Use bperm trick for iq2_ks gemm -> 7% gain

This commit is contained in:
Iwan Kawrakow
2025-08-21 17:08:16 +03:00
parent 05cd6994c8
commit eb488f98da

View File

@@ -2554,6 +2554,15 @@ template <int mmq_y, int nwarps, bool need_check> static __device__ __forceinlin
}
}
#ifdef __CUDA_ARCH__
static __device__ __forceinline__ int2 get_int_from_table_8(const int & q4, const int8_t * values) {
const uint32_t * values32 = (const uint32_t *)values;
uint32_t v1 = __byte_perm(values32[0], values32[1], q4);
uint32_t v2 = __byte_perm(values32[0], values32[1], q4 >> 16);
return make_int2(__byte_perm(v1, v2, 0x6420), __byte_perm(v1, v2, 0x7531));
}
#endif
template <int mmq_y, int nwarps, bool need_check> static __device__ __forceinline__ void load_tiles_iq2_ks(
const char * __restrict__ x, int * __restrict__ x_tile, const int & kbx0, const int & i_max, const int & stride) {
@@ -2566,11 +2575,45 @@ template <int mmq_y, int nwarps, bool need_check> static __device__ __forceinlin
float * x_df = (float *) (x_qs + txs.qs);
#endif // INT8_MMA_AVAILABLE
const int * all_values = (const int *)iq2k_table;
const int kqsx = threadIdx.x%16;
#pragma unroll
#ifdef __CUDA_ARCH__
#pragma unroll
for (int i0 = 0; i0 < mmq_y; i0 += 2*nwarps) {
int i = i0 + 2*threadIdx.y + threadIdx.x/16;
if (need_check) {
i = min(i, i_max);
}
const block_iq2_ks * bxi = (const block_iq2_ks *)(x + i*stride + sizeof(half)) + kbx0;
uint16_t extra = bxi->extra >> 4*(kqsx/8);
int q2 = get_int_b2(bxi->qs, kqsx);
uint32_t extra32 = uint32_t(extra & 0xf) * 0x01010101;
uint32_t val1 = ((q2 >> 0) & 0x33333333) | ((extra32 << 2) & 0x04040404) | ((extra32 << 4) & 0x40404040);
uint32_t val2 = ((q2 >> 2) & 0x33333333) | ((extra32 << 1) & 0x04040404) | ((extra32 << 3) & 0x40404040);
int2 v1 = get_int_from_table_8(val1, iq2nl_values);
int2 v2 = get_int_from_table_8(val2, iq2nl_values);
#ifdef INT8_MMA_AVAILABLE
x_qs[i*MMQ_MMA_TILE_X_K_Q8_0 + kqsx%8 + 32*(kqsx/8) + 0] = v1.x;
x_qs[i*MMQ_MMA_TILE_X_K_Q8_0 + kqsx%8 + 32*(kqsx/8) + 8] = v2.x;
x_qs[i*MMQ_MMA_TILE_X_K_Q8_0 + kqsx%8 + 32*(kqsx/8) + 16] = v1.y;
x_qs[i*MMQ_MMA_TILE_X_K_Q8_0 + kqsx%8 + 32*(kqsx/8) + 24] = v2.y;
#else
x_qs[i*(2*WARP_SIZE + 1) + kqsx%8 + 32*(kqsx/8) + 0] = v1.x;
x_qs[i*(2*WARP_SIZE + 1) + kqsx%8 + 32*(kqsx/8) + 8] = v2.x;
x_qs[i*(2*WARP_SIZE + 1) + kqsx%8 + 32*(kqsx/8) + 16] = v1.y;
x_qs[i*(2*WARP_SIZE + 1) + kqsx%8 + 32*(kqsx/8) + 24] = v2.y;
#endif // INT8_MMA_AVAILABLE
}
#else // __CUDA_ARCH__
const int * all_values = (const int *)iq2k_table;
#pragma unroll
for (int i0 = 0; i0 < mmq_y; i0 += 2*nwarps) {
int i = i0 + 2*threadIdx.y + threadIdx.x/16;
@@ -2595,6 +2638,7 @@ template <int mmq_y, int nwarps, bool need_check> static __device__ __forceinlin
x_qs[i*(2*WARP_SIZE + 1) + kqsx%8 + 32*(kqsx/8) + 24] = int_from_table_4((q2 >> 6) & 0x03030303, all_values + ((extra & 8) << 5));
#endif // INT8_MMA_AVAILABLE
}
#endif // __CUDA_ARCH__
#pragma unroll
for (int i0 = 0; i0 < mmq_y; i0 += nwarps * 8) {