Use the new nsw form of add for signed integer addition.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@78765 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index c0f6335..564322b 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -741,7 +741,12 @@
NextVal = llvm::ConstantInt::getTrue(VMContext);
} else if (isa<llvm::IntegerType>(InVal->getType())) {
NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal);
- NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec");
+
+ // Signed integer overflow is undefined behavior.
+ if (ValTy->isSignedIntegerType())
+ NextVal = Builder.CreateNSWAdd(InVal, NextVal, isInc ? "inc" : "dec");
+ else
+ NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec");
} else {
// Add the inc/dec to the real part.
if (InVal->getType() == llvm::Type::FloatTy)
@@ -1033,7 +1038,11 @@
if (Ops.LHS->getType()->isFPOrFPVector())
return Builder.CreateFAdd(Ops.LHS, Ops.RHS, "add");
-
+
+ // Signed integer overflow is undefined behavior.
+ if (Ops.Ty->isSignedIntegerType())
+ return Builder.CreateNSWAdd(Ops.LHS, Ops.RHS, "add");
+
return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add");
}