[all-commits] [llvm/llvm-project] 204bdc: [InstCombine][x86] fix insertion point bug in vect...

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  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 204bdc5322cc89603d503fb1f02a0eba19a1b496
      https://github.com/llvm/llvm-project/commit/204bdc5322cc89603d503fb1f02a0eba19a1b496
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2020-12-11 (Fri, 11 Dec 2020)

  Changed paths:
    M llvm/lib/Target/X86/X86InstCombineIntrinsic.cpp
    M llvm/test/Transforms/InstCombine/X86/x86-addsub.ll

  Log Message:
  -----------
  [InstCombine][x86] fix insertion point bug in vector demanded elts fold (PR48476)

This transform was added at:
c63799fc52ff

>From what I see, it's the first demanded elements transform that adds
a new instruction using the IRBuilder. There are similar folds in
the generic demanded bits chunk of instcombine that also use the
InsertPointGuard code pattern.

The tests here would assert/crash because the new instruction was
being added at the start of the demanded elements analysis rather
than at the instruction that is being replaced.