[all-commits] [llvm/llvm-project] 16da22: [InstCombine] add tests for fcmp with fneg common ...

[Sanjay Patel via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 16da22d45a7c4bfceef0fb54f49f5a2ace2e0911
      https://github.com/llvm/llvm-project/commit/16da22d45a7c4bfceef0fb54f49f5a2ace2e0911
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2022-03-10 (Thu, 10 Mar 2022)

  Changed paths:
    M llvm/test/Transforms/InstCombine/fabs.ll
    M llvm/test/Transforms/InstCombine/fcmp.ll

  Log Message:
  -----------
  [InstCombine] add tests for fcmp with fneg common operand; NFC


  Commit: 3491f2f4b0336cdb788fed3ff03a4b31c58db14e
      https://github.com/llvm/llvm-project/commit/3491f2f4b0336cdb788fed3ff03a4b31c58db14e
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2022-03-10 (Thu, 10 Mar 2022)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
    M llvm/test/Transforms/InstCombine/fabs.ll
    M llvm/test/Transforms/InstCombine/fcmp.ll

  Log Message:
  -----------
  [InstCombine] replace negated operand in fcmp with 0.0

X (any pred) -X --> X (any pred) 0.0

This works with all FP values and preserves FMF.
Alive2 examples:
https://alive2.llvm.org/ce/z/dj6jhp

This can also create one of the patterns that we match as "fabs"
as shown in one of the test diffs.


Compare: https://github.com/llvm/llvm-project/compare/28cfa764c2e3...3491f2f4b033