[all-commits] [llvm/llvm-project] dc6d07: [CVP] Infer nneg on existing zext (#72052)

[Yingwei Zheng via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: dc6d0773960c664eee12a1ed871fad5c81a20a12
      https://github.com/llvm/llvm-project/commit/dc6d0773960c664eee12a1ed871fad5c81a20a12
  Author: Yingwei Zheng <dtcxzyw2333 at gmail.com>
  Date:   2023-11-13 (Mon, 13 Nov 2023)

  Changed paths:
    M llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
    A llvm/test/Transforms/CorrelatedValuePropagation/zext.ll
    M llvm/test/Transforms/LoopVectorize/X86/float-induction-x86.ll
    M llvm/test/Transforms/PhaseOrdering/X86/excessive-unrolling.ll
    M llvm/test/Transforms/PhaseOrdering/X86/pixel-splat.ll
    M llvm/test/Transforms/PhaseOrdering/X86/vdiv.ll

  Log Message:
  -----------
  [CVP] Infer nneg on existing zext (#72052)

This patch infers `nneg` flags for existing zext instructions in CVP.
After https://github.com/llvm/llvm-project/pull/71534 and this patch, we
can drop `zext -> zext nneg` transform in `RISCVCodeGenPrepare`:


https://github.com/llvm/llvm-project/blob/40671bbdefb6ff83e2685576a3cb041b62f25bbe/llvm/lib/Target/RISCV/RISCVCodeGenPrepare.cpp#L74-L83

This is an alternative to #72049.