[all-commits] [llvm/llvm-project] 9cd7c5: [InstCombine] Enable fold select into operand for ...

[huihzhang via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 9cd7c534e27c2558ef16e14d4440bd838320334b
      https://github.com/llvm/llvm-project/commit/9cd7c534e27c2558ef16e14d4440bd838320334b
  Author: Huihui Zhang <huihuiz at quicinc.com>
  Date:   2021-11-22 (Mon, 22 Nov 2021)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
    M llvm/test/Transforms/InstCombine/select-binop-foldable-floating-point.ll
    M llvm/test/Transforms/LoopVectorize/ARM/mve-selectandorcost.ll
    M llvm/test/Transforms/LoopVectorize/reduction-inloop-pred.ll
    M llvm/test/Transforms/LoopVectorize/reduction-inloop.ll
    M llvm/test/Transforms/PhaseOrdering/AArch64/hoisting-sinking-required-for-vectorization.ll

  Log Message:
  -----------
  [InstCombine] Enable fold select into operand for FAdd,  FMul, FSub and FDiv.

For FAdd, FMul, FSub and FDiv, fold select into one of the operands to enable
further optimizations, i.e., floating-point reduction detection.

Turn code:
  %C = fadd %A, %B
  %D = select %cond, %C, %A

into:
  %C = select %cond, %B, -0.000000e+00
  %D = fadd %A, %C

Alive2 verification (with --disable-undef-input), timed out otherwise.
FAdd - https://alive2.llvm.org/ce/z/eUxN4Y
FMul - https://alive2.llvm.org/ce/z/5SWZz4
FSub - https://alive2.llvm.org/ce/z/Dhj8dU
FDiv - https://alive2.llvm.org/ce/z/Yj_NA2

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D113442