[all-commits] [llvm/llvm-project] cae46f: [MCP] Enhance MCP copy Instruction removal for spe...

[Vettel via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: cae46f6210293ba4d3568eb21b935d438934290d
      https://github.com/llvm/llvm-project/commit/cae46f6210293ba4d3568eb21b935d438934290d
  Author: Vettel <924105575 at qq.com>
  Date:   2023-11-22 (Wed, 22 Nov 2023)

  Changed paths:
    M llvm/lib/CodeGen/MachineCopyPropagation.cpp
    M llvm/test/CodeGen/RISCV/machine-cp.mir
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-nearbyint-vp.ll
    M llvm/test/CodeGen/X86/shift-i128.ll
    M llvm/test/CodeGen/X86/shift-i256.ll
    M llvm/test/CodeGen/X86/smulo-128-legalisation-lowering.ll
    M llvm/test/CodeGen/X86/vector-interleaved-load-i16-stride-7.ll
    M llvm/test/CodeGen/X86/vector-interleaved-load-i64-stride-7.ll
    M llvm/test/CodeGen/X86/vector-interleaved-load-i8-stride-5.ll
    M llvm/test/CodeGen/X86/vector-interleaved-load-i8-stride-7.ll
    M llvm/test/CodeGen/X86/vector-interleaved-load-i8-stride-8.ll
    M llvm/test/CodeGen/X86/vector-interleaved-store-i16-stride-7.ll
    M llvm/test/CodeGen/X86/wide-scalar-shift-legalization.ll

  Log Message:
  -----------
  [MCP] Enhance MCP copy Instruction removal for special case (#70778)

Machine Copy Propagation Pass may lose some opportunities to further
remove the redundant copy instructions during the ForwardCopyPropagateBlock
procedure. When we Clobber a "Def" register, we also need to remove the record 
from the copy maps that indicates "Src" defined "Def" to ensure the correct semantics
of the ClobberRegister function.

For more information, please see the C++ test case generated code in 
"vector.body" after the MCP Pass: https://gcc.godbolt.org/z/nK4oMaWv5.