[BUG] Wrong default reduction_identity on Epilogue Reduction Store operations

[bdh0404]

Describe the bug
For my custom EVT computation, I used a Sm90RowReduction class with half-precision floating point addition reduction, with the default reduction identity as ElementCompute(0.0f) where the ElementCompute is cutlass::half_t as argument input. However, a compile error occurred due to the incorrectly stated default value of reduction_identity.

Steps/Code to reproduce bug

/home/user/workspace/cutlass/include/cutlass/epilogue/fusion/sm90_visitor_store_tma_warpspecialized.hpp(683): error: no suitable constructor exists to convert from "int" to "cutlass::half_t"
ElementCompute reduction_identity = 0;

Where the ElementCompute is cutlass::half_t.

The EVT I used for is
cutlass::epilogue::fusion::Sm90EVT<
cutlass::epilogue::fusion::Sm90RowReduction<cutlass::plus, cutlass::plus, cutlass::plus, 0, TileShape, ElementCompute, ElementCompute,
RoundStyle>,
...>
Which accumulates epilogue results row-wise with half-precision floating-point addition.

This compile bug happens due to an incorrectly stated default value of reduction_identity.

Expected behavior

No compile error.

Environment details (please complete the following information):

• Docker Nvidia CUDA 12.6.3 image

Additional context

Changing the default values of reduction_identity variables of those reduction classes from "0" to "ElementCompute(0)" eliminates the compile error.

[thakkarV]

thanks for the bug report!

[hwu36]

@Junkai-Wu