[PATCH] D152147: [RISCV] Fold binary op into select if profitable.

Fri Jul 14 09:59:42 PDT 2023

mgudim added inline comments.

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Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:5846

+  if (Op.hasOneUse() && isBinOp(Op->use_begin()->getOpcode())) {
+    SDNode *BinOp = *Op->use_begin();
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craig.topper wrote:
> Is this safe for division/remainder? The select could be sanitizing inputs. RISC-V doesn't have traps for div/rem, but IR/SelectionDAG semantics consider division by 0 to be immediate UB. Same with (sdiv -1, INT_MIN)
Thanks, I never thought about that.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D152147/new/

https://reviews.llvm.org/D152147