chech bias pointer is nullptr

include/ck/tensor_operation/gpu/grid/gridwise_batched_mha_bwd_xdl_cshuffle_qloop_b2t_v2.hpp

@@ -2335,6 +2335,8 @@ struct GridwiseBatchedMultiheadAttentionBackward_Qloop_Xdl_CShuffle_V2
 
             // add bias
             if constexpr(!is_same<D0DataType, void>::value)
+            {
+                if(p_d0_grid != nullptr)
                 {
                     static constexpr auto& c_thread_desc = s_blockwise_gemm.GetCThreadDesc();
 
@@ -2361,7 +2363,8 @@ struct GridwiseBatchedMultiheadAttentionBackward_Qloop_Xdl_CShuffle_V2
                             D0Operator::d0_block_global_desc_m0_n0_m1_m2_n1_m3, d0_block_buf);
                         block_sync_lds();
                         // read data form lds
-                    d0_thread_copy_lds_to_vgpr.Run(D0Operator::d0_block_vgpr_desc_n0_n1_m0_m1_m2,
+                        d0_thread_copy_lds_to_vgpr.Run(
+                            D0Operator::d0_block_vgpr_desc_n0_n1_m0_m1_m2,
                             make_tuple(I0, I0, I0, I0, I0),
                             d0_block_buf,
                             D0Operator::d0_thread_desc_,
@@ -2379,7 +2382,9 @@ struct GridwiseBatchedMultiheadAttentionBackward_Qloop_Xdl_CShuffle_V2
                     });
 
                     d0_block_copy_global_to_lds.MoveSrcSliceWindow(
-                    d0_grid_desc_m0_n0_m1_m2_n1_m3, make_multi_index(-1, 0, -D0M0.value, 0, 0, 0));
+                        d0_grid_desc_m0_n0_m1_m2_n1_m3,
+                        make_multi_index(-1, 0, -D0M0.value, 0, 0, 0));
+                }
             }
 
             // do MNK padding or upper triangular masking
@@ -2607,6 +2612,8 @@ struct GridwiseBatchedMultiheadAttentionBackward_Qloop_Xdl_CShuffle_V2
             });
             // output bias grad
             if constexpr(!is_same<D0DataType, void>::value)
+            {
+                if(p_d0grad_grid != nullptr)
                 {
                     auto d0grad_grid_buf = make_dynamic_buffer<AddressSpaceEnum::Global>(
                         p_d0grad_grid, d0_grid_desc_m0_n0_m1_m2_n1_m3.GetElementSpaceSize());
@@ -2638,7 +2645,9 @@ struct GridwiseBatchedMultiheadAttentionBackward_Qloop_Xdl_CShuffle_V2
                     });
 
                     d0_block_copy_lds_to_global.MoveDstSliceWindow(
-                    d0_grid_desc_m0_n0_m1_m2_n1_m3, make_multi_index(-1, 0, -D0M0.value, 0, 0, 0));
+                        d0_grid_desc_m0_n0_m1_m2_n1_m3,
+                        make_multi_index(-1, 0, -D0M0.value, 0, 0, 0));
+                }
             }
 
             SubThreadBlock<BlockSize> gemm2_a_copy_subgroup(s_blockwise_gemm.GetWaveIdx()[I0],