================
@@ -1898,6 +1882,60 @@ static Instruction *foldSelectICmpEq(SelectInst &SI,
ICmpInst *ICI,
return nullptr;
}
+/// Fold `X Pred C1 ? X BOp C2 : C1 BOp C2` to `min/max(X, C1) BOp C2`.
+/// This allows for better canonicalization.
+static Value *foldSelectWithConstOpToBinOp(ICmpInst *Cmp, Value *TrueVal,
+ Value *FalseVal,
+ IRBuilderBase &Builder) {
+ BinaryOperator *BOp;
+ Constant *C1, *C2, *C3;
+ Value *X;
+ ICmpInst::Predicate Predicate;
+
+ if (!match(Cmp, m_ICmp(Predicate, m_Value(X), m_Constant(C1))))
+ return nullptr;
+
+ if (!ICmpInst::isRelational(Predicate))
+ return nullptr;
+
+ if (match(TrueVal, m_Constant())) {
+ std::swap(FalseVal, TrueVal);
+ Predicate = ICmpInst::getInversePredicate(Predicate);
+ }
+
+ if (!match(TrueVal, m_BinOp(BOp)) || !match(FalseVal, m_Constant(C3)))
+ return nullptr;
+
+ unsigned Opcode = BOp->getOpcode();
+
+ if (Instruction::isIntDivRem(Opcode))
----------------
veera-sivarajan wrote:
Yeah, it's a heuristic. I've added a comment.
https://github.com/llvm/llvm-project/pull/116888
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