indvars -disable-iv-rewrite: handle cloning binary operators that cannot overflow.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134177 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index 00f8831..77642e5 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -659,9 +659,11 @@
LHS, RHS,
NarrowBO->getName());
Builder.Insert(WideBO);
- if (NarrowBO->hasNoUnsignedWrap()) WideBO->setHasNoUnsignedWrap();
- if (NarrowBO->hasNoSignedWrap()) WideBO->setHasNoSignedWrap();
-
+ if (const OverflowingBinaryOperator *OBO =
+ dyn_cast<OverflowingBinaryOperator>(NarrowBO)) {
+ if (OBO->hasNoUnsignedWrap()) WideBO->setHasNoUnsignedWrap();
+ if (OBO->hasNoSignedWrap()) WideBO->setHasNoSignedWrap();
+ }
return WideBO;
}
llvm_unreachable(0);
@@ -1121,6 +1123,8 @@
while (!SimpleIVUsers.empty()) {
Instruction *UseInst, *Operand;
tie(UseInst, Operand) = SimpleIVUsers.pop_back_val();
+ // Bypass back edges to avoid extra work.
+ if (UseInst == CurrIV) continue;
if (EliminateIVUser(UseInst, Operand)) {
pushIVUsers(Operand, Simplified, SimpleIVUsers);