diff --git a/tests/test_fmha_v3_softmax.py b/tests/test_fmha_v3_softmax.py index cbff5a44..166dc904 100644 --- a/tests/test_fmha_v3_softmax.py +++ b/tests/test_fmha_v3_softmax.py @@ -63,6 +63,7 @@ class FmhaV3Softmax: q_s = cute.slice_(self.q_smem_s,(None,None,None,0)); k_s = cute.slice_(self.k_smem_s,(None,None,None,0)) self.q_tx_bytes = cute.size_in_bytes(self.q_dtype, q_s) * cta self.kv_tx_bytes = cute.size_in_bytes(self.q_dtype, k_s) * cta + self.scale_softmax_log2 = Float32(1.0 / math.sqrt(HEAD_DIM) * math.log2(math.e)) @cute.jit def __call__(self, q, k, v, c, stream): @@ -348,16 +349,34 @@ class FmhaV3Softmax: row_sum = row_sum + tile_sum - # --- C9: Final normalization + epilogue TMA store --- + # --- C9: Final normalization via O TMEM rescale --- + # After all KV tiles, O = sum(P_i @ V_i) but unnormalized. + # Load O, multiply by 1/row_sum, store O. Then use identity epilogue. + inv_row_sum = cutlass.Float32(1.0) / row_sum + + tTMrO_final = cute.make_rmem_tensor((tTMEM_LOADcO.shape, o_col_tiles), self.qk_acc_dtype) + for i in range(o_col_tiles): + tTMrO_i_ = tTMrO_final[None, i] + tTMrO_i_layout = cute.composition(tTMrO_i_.layout, cute.make_layout(tTMrO_final.shape[0])) + tTMrO_i = cute.make_tensor(tTMrO_i_.iterator, tTMrO_i_layout) + tTMEM_LOADtO_i = cute.make_tensor( + tTMEM_LOADtO.iterator + i * corr_tile_size, tTMEM_LOADtO.layout) + tTMEM_STOREtO_i = cute.make_tensor( + tTMEM_STOREtO.iterator + i * corr_tile_size, tTMEM_STOREtO.layout) + cute.copy(o_tiled_tmem_load, tTMEM_LOADtO_i, tTMrO_i) + for j in cutlass.range(cute.size(tTMrO_i), vectorize=True): + tTMrO_i[j] = tTMrO_i[j] * inv_row_sum + cute.copy(o_tiled_tmem_store, tTMrO_i, tTMEM_STOREtO_i) + cute.arch.fence_view_async_tmem_store() + + # Now O in TMEM is normalized. Use standard epilogue_tma_store with identity. tCtO_base = cute.make_tensor(tmem_ptr + self.tmem_o0_offset, tCtO_fake.layout) acc_cons_st = pipeline.make_pipeline_state(pipeline.PipelineUserType.Consumer, self.num_acc_stage) c_grp = pipeline.CooperativeGroup(pipeline.Agent.Thread, 32 * len(self.epilogue_warp_id)) c_pipe = pipeline.PipelineTmaStore.create(num_stages=self.num_c_stage, producer_group=c_grp) - # C9: Normalize by 1/row_sum - inv_row_sum = cutlass.Float32(1.0) / row_sum acc_cons_st = utils.gemm.sm100.epilogue_tma_store( self, tidx, warp_idx, tma_c, tCtO_base, sC, tCgC, epi_tile, 0, - const_expr(lambda x, s=inv_row_sum: x * s), + const_expr(lambda x: x), (0,0,0), acc_cons_st, acc_pipe, c_pipe) c_pipe.producer_tail() tmem.relinquish_alloc_permit()