@@ -540,10 +540,12 @@ static __device__ __forceinline__ void flash_attn_tile_iter(
540540 KQ_acc[(i_KQ_0/(np*warp_size))*cpw + jc0] = logit_softcap * tanhf (KQ_acc[(i_KQ_0/(np*warp_size))*cpw + jc0]);
541541 }
542542
543- KQ_acc[(i_KQ_0/(np*warp_size))*cpw + jc0] += (ncols2 > 1 || mask) && (!oob_check || i_KQ < k_VKQ_sup) ?
544- slope*__half2float (mask[j*stride_mask + k_VKQ_0 + i_KQ]) : 0 .0f ;
543+ if (!oob_check || i_KQ < k_VKQ_sup) {
544+ KQ_acc[(i_KQ_0/(np*warp_size))*cpw + jc0] += (ncols2 > 1 || mask) ?
545+ slope*__half2float (mask[j*stride_mask + k_VKQ_0 + i_KQ]) : 0 .0f ;
545546
546- KQ_max_new[jc0] = fmaxf (KQ_max_new[jc0], KQ_acc[(i_KQ_0/(np*warp_size))*cpw + jc0]);
547+ KQ_max_new[jc0] = fmaxf (KQ_max_new[jc0], KQ_acc[(i_KQ_0/(np*warp_size))*cpw + jc0]);
548+ }
547549 }
548550
549551 KQ_max_new[jc0] = warp_reduce_max<warp_size>(KQ_max_new[jc0]);
@@ -581,10 +583,9 @@ static __device__ __forceinline__ void flash_attn_tile_iter(
581583 float KQ_sum_add = 0 .0f ;
582584#pragma unroll
583585 for (int i0 = 0 ; i0 < nbatch_fa; i0 += np*warp_size) {
584- const float val = expf (KQ_acc[(i0/(np*warp_size))*cpw + jc] - KQ_max[jc]);
585- if (!oob_check || i0 + (threadIdx .y % np)*warp_size + threadIdx .x < k_VKQ_sup) {
586- KQ_sum_add += val;
587- }
586+ const float val = !oob_check || i0 + (threadIdx .y % np)*warp_size + threadIdx .x < k_VKQ_sup ?
587+ expf (KQ_acc[(i0/(np*warp_size))*cpw + jc] - KQ_max[jc]) : 0 .0f ;
588+ KQ_sum_add += val;
588589 tmp[i0/(np*warp_size)][jc1] = val;
589590 }
590591 KQ_sum[jc] = KQ_sum[jc]*KQ_max_scale + KQ_sum_add;
@@ -975,26 +976,6 @@ static __global__ void flash_attn_tile(
975976 }
976977 }
977978
978- if (gridDim .y == 1 ) {
979- #pragma unroll
980- for (int jc0 = 0 ; jc0 < cpw; ++jc0) {
981- #ifdef FAST_FP16_AVAILABLE
982- const half2 KQ_sum_jc_inv = make_half2 (1 .0f /KQ_sum[jc0], 1 .0f /KQ_sum[jc0]);
983- #pragma unroll
984- for (int i = 0 ; i < (DVp/2 )/warp_size; ++i) {
985- VKQ[jc0*((DVp/2 )/warp_size) + i] *= KQ_sum_jc_inv;
986- }
987- #else
988- const float KQ_sum_jc_inv = 1 .0f /KQ_sum[jc0];
989- #pragma unroll
990- for (int i = 0 ; i < (DVp/2 )/warp_size; ++i) {
991- VKQ[jc0*((DVp/2 )/warp_size) + i].x *= KQ_sum_jc_inv;
992- VKQ[jc0*((DVp/2 )/warp_size) + i].y *= KQ_sum_jc_inv;
993- }
994- #endif // FAST_FP16_AVAILABLE
995- }
996- }
997-
998979 // Write back results:
999980#pragma unroll
1000981 for (int jc0 = 0 ; jc0 < cpw; ++jc0) {
@@ -1007,6 +988,8 @@ static __global__ void flash_attn_tile(
1007988 return ;
1008989 }
1009990
991+ const float scale = gridDim .y == 1 ? 1 .0f /KQ_sum[jc0] : 1 .0f ;
992+
1010993 const int j_dst_unrolled = ((sequence*ne01 + col_Q_0 + j)*ne02 + head0 + c)*gridDim .y + blockIdx .y ;
1011994
1012995#ifdef FAST_FP16_AVAILABLE
@@ -1017,6 +1000,8 @@ static __global__ void flash_attn_tile(
10171000#pragma unroll
10181001 for (int i1 = 0 ; i1 < cpy_ne_D; ++i1) {
10191002 tmp[i1] = __half22float2 (VKQ[jc0*((DVp/2 )/warp_size) + i0/warp_size + i1]);
1003+ tmp[i1].x *= scale;
1004+ tmp[i1].y *= scale;
10201005 }
10211006 if (i0 + warp_size*cpy_ne_D <= DV/2 || i0 + threadIdx .x *cpy_ne_D < DV/2 ) {
10221007 ggml_cuda_memcpy_1<sizeof (tmp)>(&dst[j_dst_unrolled*DV + 2 *i0 + threadIdx .x *(2 *cpy_ne_D)], tmp);
@@ -1027,6 +1012,11 @@ static __global__ void flash_attn_tile(
10271012#pragma unroll
10281013 for (int i0 = 0 ; i0 < DVp; i0 += warp_size*cpy_ne_D) {
10291014 if (i0 + warp_size*cpy_ne_D <= DV || i0 + threadIdx .x *cpy_ne_D < DV) {
1015+ #pragma unroll
1016+ for (int i1 = 0 ; i1 < cpy_ne_D/2 ; ++i1) {
1017+ VKQ[jc0*((DVp/2 )/warp_size) + i0/(2 *warp_size) + i1].x *= scale;
1018+ VKQ[jc0*((DVp/2 )/warp_size) + i0/(2 *warp_size) + i1].y *= scale;
1019+ }
10301020 ggml_cuda_memcpy_1<cpy_ne_D*4 >(
10311021 &dst[j_dst_unrolled*DV + i0 + threadIdx .x *cpy_ne_D],
10321022 &VKQ[jc0*((DVp/2 )/warp_size) + i0/(2 *warp_size)]);
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