[ConstantRange] Optimize smul nowrap with constant (NFC)

Don't call makeExactMulNSWRegion() twice with the same value.
llvm · Sep 15, 2023 · ab6667f · ab6667f
1 parent 73371fa
commit ab6667f
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp
@@ -326,6 +326,10 @@ ConstantRange::makeGuaranteedNoWrapRegion(Instruction::BinaryOps BinOp,
     if (Unsigned)
       return makeExactMulNUWRegion(Other.getUnsignedMax());
 
+    // Avoid one makeExactMulNSWRegion() call for the common case of constants.
+    if (const APInt *C = Other.getSingleElement())
+      return makeExactMulNSWRegion(*C);
+
     return makeExactMulNSWRegion(Other.getSignedMin())
         .intersectWith(makeExactMulNSWRegion(Other.getSignedMax()));