[PATCH] D123014: [X86][FastISel] Remove with.overflow + select fold (PR54369)

[Nikita Popov via Phabricator via llvm-commits]

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This is an alternative to D122825 <https://reviews.llvm.org/D122825>. Instead of trying to account for possible EFLAGS clobber by constant materialization, remove the with.overflow + select fold entirely, on the premise that non-trivial/fragile folds like this don't belong in FastISel. I've kept the with.overflow + br fold for now, as we don't have any known issues for that one.

Fixes https://github.com/llvm/llvm-project/issues/54369.


https://reviews.llvm.org/D123014

Files:
  llvm/lib/Target/X86/X86FastISel.cpp
  llvm/test/CodeGen/X86/pr54369.ll
  llvm/test/CodeGen/X86/xaluo.ll
  llvm/test/CodeGen/X86/xmulo.ll

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