[all-commits] [llvm/llvm-project] 90ae53: [SCEV] Prove implication of predicates to their si...

[Max Kazantsev via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 90ae538cab4b0535450b079244241424ff90711c
      https://github.com/llvm/llvm-project/commit/90ae538cab4b0535450b079244241424ff90711c
  Author: Max Kazantsev <mkazantsev at azul.com>
  Date:   2021-10-15 (Fri, 15 Oct 2021)

  Changed paths:
    M llvm/lib/Analysis/ScalarEvolution.cpp
    M llvm/test/Transforms/IndVarSimplify/outer_phi.ll

  Log Message:
  -----------
  [SCEV] Prove implication of predicates to their sign-flipped counterparts

This patch teaches SCEV two implication rules:

  x <u y && y >=s 0 --> x <s y,
  x <s y && y <s 0 --> x <u y.

And all equivalents with signs/parts swapped.

Differential Revision: https://reviews.llvm.org/D110517
Reviewed By: nikic