[all-commits] [llvm/llvm-project] 761f56: Revert "[X86] Increase the number of instructions ...

[topperc via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 761f568420a5738a064a0d4203a0f2d783343102
      https://github.com/llvm/llvm-project/commit/761f568420a5738a064a0d4203a0f2d783343102
  Author: Craig Topper <craig.topper at intel.com>
  Date:   2020-08-08 (Sat, 08 Aug 2020)

  Changed paths:
    M llvm/lib/Target/X86/X86FixupLEAs.cpp
    M llvm/lib/Target/X86/X86InstrInfo.cpp
    M llvm/lib/Target/X86/X86InstrInfo.h
    M llvm/test/CodeGen/X86/optimize-max-0.ll

  Log Message:
  -----------
  Revert "[X86] Increase the number of instructions searched for isSafeToClobberEFLAGS in a couple places"

This reverts commit 44b260cb0aab387d85e4d59c16fc7b8866264f5e.

I messed up the bug number in the commit message so I'm reverting
to fix it.


  Commit: 8d3ae64b0403a2718c7e9c21a6595575af040ffc
      https://github.com/llvm/llvm-project/commit/8d3ae64b0403a2718c7e9c21a6595575af040ffc
  Author: Craig Topper <craig.topper at intel.com>
  Date:   2020-08-08 (Sat, 08 Aug 2020)

  Changed paths:
    M llvm/lib/Target/X86/X86FixupLEAs.cpp
    M llvm/lib/Target/X86/X86InstrInfo.cpp
    M llvm/lib/Target/X86/X86InstrInfo.h
    M llvm/test/CodeGen/X86/optimize-max-0.ll
    A llvm/test/CodeGen/X86/pr47024.ll

  Log Message:
  -----------
  Recommit "[X86] Increase the number of instructions searched for isSafeToClobberEFLAGS in a couple places"

I messed up the bug numbers in the commit message before

Previously this function searched 4 instructions forwards or
backwards to determine if it was ok to clobber eflags.

This is called in 3 places: rematerialization, turning 2 operand
leas into adds or splitting 3 ops leas into an lea and add on some
CPU targets.

This patch increases the search limit to 10 instructions for
rematerialization and 2 operand lea to add. I've left the old
treshold for 3 ops lea spliting as that increases code size.

Fixes PR47024 and PR46315.


Compare: https://github.com/llvm/llvm-project/compare/4cc914280fbe...8d3ae64b0403