[all-commits] [llvm/llvm-project] 107601: [InstCombine] Allow min/max in constant BOp min/ma...

[Alex MacLean via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 107601ed063f9e92aba61ea4f2a36c372127a82a
      https://github.com/llvm/llvm-project/commit/107601ed063f9e92aba61ea4f2a36c372127a82a
  Author: Alex MacLean <amaclean at nvidia.com>
  Date:   2025-06-06 (Fri, 06 Jun 2025)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
    M llvm/test/Transforms/InstCombine/canonicalize-const-to-bop.ll

  Log Message:
  -----------
  [InstCombine] Allow min/max in constant BOp min/max folding (#142878)

Extend folding for `X Pred C2 ? X BOp C1 : C2 BOp C1` to `min/max(X, C2)
BOp C1` to allow min and max as `BOp`. This ensures a constant clamping
pattern is folded into a pair of min/max instructions. Here is a
simplified example of a case where this folding is not occurring
currently.

int clampToU8(int v) {
    if (v < 0) return 0;
    if (v > 255) return 255;
    return v;
}

https://godbolt.org/z/78jhKPWbv

Generic proof: https://alive2.llvm.org/ce/z/cdpLYy



To unsubscribe from these emails, change your notification settings at https://github.com/llvm/llvm-project/settings/notifications