[all-commits] [llvm/llvm-project] 0f9109: [NVPTX] Eliminate StoreRetval instructions with un...

[Daniil Kovalev via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 0f9109cc9d89a0da1b9fa556136286df66505912
      https://github.com/llvm/llvm-project/commit/0f9109cc9d89a0da1b9fa556136286df66505912
  Author: Daniil Kovalev <daniil at kovalev.website>
  Date:   2022-02-10 (Thu, 10 Feb 2022)

  Changed paths:
    M llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
    A llvm/test/CodeGen/NVPTX/store-retval.ll

  Log Message:
  -----------
  [NVPTX] Eliminate StoreRetval instructions with undef operand

Previously a lot of StoreRetval instructions with undef operand were
generated on NVPTX target when a big struct was returned by value.
It resulted in a lot of unneeded st.param.* instructions in final
assembly. The patch solves the issue by implementing the logic in
NVPTX-specific part of DAG combiner.

Differential Revision: https://reviews.llvm.org/D118973