[all-commits] [llvm/llvm-project] 5d7d68: [InstCombine] fix propagation of FMF through selec...

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  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5d7d689edf01e41d908ced188efcc6405627fd2b
      https://github.com/llvm/llvm-project/commit/5d7d689edf01e41d908ced188efcc6405627fd2b
  Author: Sanjay Patel <spatel at octomac.myfiosgateway.com>
  Date:   2021-08-31 (Tue, 31 Aug 2021)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
    M llvm/test/Transforms/InstCombine/fneg.ll

  Log Message:
  -----------
  [InstCombine] fix propagation of FMF through select-of-fnegs

The existing code was unquestionably wrong - it looked at one
fneg and ignored the other 2 instructions.

It was also untested, so it didn't make the list of bugs
flagged by Alive2.

This is an unusual propagation, but Alive2 agress that we
can intersect the fnegs and union that with the select,
then apply the results to both new instructions:
https://alive2.llvm.org/ce/z/SF8_dt