Document what this check is doing. Also, no need to cast to ConstantInt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60369 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index e4ddecf..9ee375c 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -2933,10 +2933,10 @@
// -X/C -> X/-C, if and only if negation doesn't overflow.
if (Value *LHSNeg = dyn_castNegVal(Op0)) {
if (ConstantInt *CI = dyn_cast<ConstantInt>(LHSNeg)) {
- ConstantInt *RHSNeg = cast<ConstantInt>(ConstantExpr::getNeg(RHS));
- if (RHS != RHSNeg) {
- ConstantInt *CINeg = cast<ConstantInt>(ConstantExpr::getNeg(CI));
- if (CI != CINeg)
+ Constant *RHSNeg = ConstantExpr::getNeg(RHS);
+ if (RHS != RHSNeg) { // Check that there is no overflow.
+ Constant *CINeg = ConstantExpr::getNeg(CI);
+ if (CI != CINeg) // Check that there is no overflow.
return BinaryOperator::CreateSDiv(LHSNeg,
ConstantExpr::getNeg(RHS));
}