[all-commits] [llvm/llvm-project] f8742b: [SCEV] Teach SCEVExpander to use zext nneg when po...

[Philip Reames via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f8742b8d6a3489dc8974f4166d413a66cb8d9c21
      https://github.com/llvm/llvm-project/commit/f8742b8d6a3489dc8974f4166d413a66cb8d9c21
  Author: Philip Reames <preames at rivosinc.com>
  Date:   2023-10-31 (Tue, 31 Oct 2023)

  Changed paths:
    M llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
    M llvm/test/Transforms/IRCE/iv-plus-offset-range-check.ll
    M llvm/test/Transforms/IRCE/wide_indvar.ll
    M llvm/test/Transforms/IndVarSimplify/promote-iv-to-eliminate-casts.ll
    M llvm/test/Transforms/IndVarSimplify/zext-nuw.ll
    M llvm/test/Transforms/LoopIdiom/X86/memset-size-compute.ll
    M llvm/test/Transforms/LoopVectorize/reduction.ll
    M polly/test/CodeGen/partial_write_in_region_with_loop.ll

  Log Message:
  -----------
  [SCEV] Teach SCEVExpander to use zext nneg when possible (#70815)

zext nneg was recently added to the IR in #67982. Teaching SCEVExpander
to emit nneg when possible is valuable since SCEV may have proved
non-trivial facts about loop bounds which would otherwise be lost when
materializing the value.