[PATCH] D102275: [x86] try to use PCMPGT instead of not-of-PCMPEQ

[Sanjay Patel via Phabricator via llvm-commits]

spatel created this revision.
spatel added reviewers: RKSimon, pengfei, craig.topper.
Herald added subscribers: hiraditya, mcrosier.
spatel requested review of this revision.
Herald added a project: LLVM.

This is motivated by the example in https://llvm.org/PR50055 , but it doesn't do anything for that bug currently because we don't actually have a zero-extended setcc there. We'll need to do something else to see through to the ideal compare code on that one.

Proof for the generic transform (inverse of what we would try to do in combining):
https://alive2.llvm.org/ce/z/aBL-Mg


https://reviews.llvm.org/D102275

Files:
  llvm/lib/Target/X86/X86ISelLowering.cpp
  llvm/test/CodeGen/X86/setcc-lowering.ll
  llvm/test/CodeGen/X86/vec_umulo.ll
  llvm/test/CodeGen/X86/vsel-cmp-load.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D102275.344544.patch
Type: text/x-patch
Size: 7295 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210511/d6ff1c4a/attachment.bin>