[PATCH] D66607: [InstCombine] matchThreeWayIntCompare(): commutativity awareness

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri created this revision.
lebedev.ri added reviewers: spatel, nikic, efriedma, xbolva00.
lebedev.ri added a project: LLVM.
Herald added a subscriber: hiraditya.
lebedev.ri added a parent revision: D66232: [InstCombine] Try to reuse constant from select in leading comparison.

`matchThreeWayIntCompare()` looks for

  select i1 (a == b),
         i32 Equal,
         i32 (select i1 (a < b), i32 Less, i32 Greater)

but both of these selects/compares can be in it's commuted form,
so out of 4 variants, only the most basic one is handled.
This fixes regression being introduced in D66232 <https://reviews.llvm.org/D66232>.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D66607

Files:
  llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
  llvm/test/Transforms/InstCombine/unrecognized_three-way-comparison.ll

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