Set NSW/NUW flags on SCEVAddExpr when the operation is flagged as
such.
I'm doing this now for completeness because I can't think of/remember
any reason that it was left out. I'm not sure it will help anything,
but if we don't do it we need to explain why in comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139450 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 57c4265..b1662a0 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -3546,7 +3546,13 @@
AddOps.push_back(Op1);
}
AddOps.push_back(getSCEV(U->getOperand(0)));
- return getAddExpr(AddOps);
+ SCEV::NoWrapFlags Flags = SCEV::FlagAnyWrap;
+ OverflowingBinaryOperator *OBO = cast<OverflowingBinaryOperator>(V);
+ if (OBO->hasNoSignedWrap())
+ setFlags(Flags, SCEV::FlagNSW);
+ if (OBO->hasNoUnsignedWrap())
+ setFlags(Flags, SCEV::FlagNUW);
+ return getAddExpr(AddOps, Flags);
}
case Instruction::Mul: {
// See the Add code above.