[all-commits] [llvm/llvm-project] 772533: [X86] Narrow i64 compares with constant to i32 whe...

[topperc via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 772533d9214b6e23762847fc7080a4201396fb10
      https://github.com/llvm/llvm-project/commit/772533d9214b6e23762847fc7080a4201396fb10
  Author: Craig Topper <craig.topper at intel.com>
  Date:   2019-10-29 (Tue, 29 Oct 2019)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/2009-02-26-MachineLICMBug.ll
    M llvm/test/CodeGen/X86/cmp.ll
    M llvm/test/CodeGen/X86/ctpop-combine.ll
    M llvm/test/CodeGen/X86/pr37063.ll

  Log Message:
  -----------
  [X86] Narrow i64 compares with constant to i32 when the upper 32-bits are known zero.

This catches some cases. There are probably ways to improve this.
I tried doing it as a combine on the setcc, but that broke
some cases involving flag reuse in place of test.

I renamed the isX86CCUnsigned to isX86CCSigned and flipped its
polarity to make it consistent with the similar functions for
ISD::SETCC. This avoids calling EQ/NE as being signed or unsigned.

Fixes PR43823.

Differential Revision: https://reviews.llvm.org/D69499