[all-commits] [llvm/llvm-project] 4224a3: [InstCombine] avoid creating an extra instruction ...

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  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 4224a36957420744756d6a6450eb6502a1bfadc3
      https://github.com/llvm/llvm-project/commit/4224a36957420744756d6a6450eb6502a1bfadc3
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2021-03-13 (Sat, 13 Mar 2021)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
    M llvm/test/Transforms/InstCombine/zext-or-icmp.ll

  Log Message:
  -----------
  [InstCombine] avoid creating an extra instruction in zext fold and possible inf-loop

The structure of this fold is suspect vs. most of instcombine
because it creates instructions and tries to delete them
immediately after.

If we don't have the operand types for the icmps, then we are
not behaving as assumed. And as shown in PR49475, we can inf-loop.