[PATCH] D69499: [X86] Narrow i64 compares with constant to i32 when the upper 32-bits are known zero.

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.
craig.topper added reviewers: spatel, RKSimon.
Herald added subscribers: asbirlea, hiraditya.
Herald added a project: LLVM.

This catches some cases. There are probably ways to improve this.
I tried just doing it as a combine on the setcc, but that broke
some cases.

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.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D69499

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

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