Fix reassociate to clear optional flags, such as nsw.
llvm-svn: 124712
diff --git a/llvm/lib/Transforms/Scalar/Reassociate.cpp b/llvm/lib/Transforms/Scalar/Reassociate.cpp
index 396b329..5df6f37 100644
--- a/llvm/lib/Transforms/Scalar/Reassociate.cpp
+++ b/llvm/lib/Transforms/Scalar/Reassociate.cpp
@@ -240,6 +240,12 @@
RHS->setOperand(0, LHS);
I->setOperand(0, RHS);
+ // Conservatively clear all the optional flags, which may not hold
+ // after the reassociation.
+ I->clearSubclassOptionalData();
+ LHS->clearSubclassOptionalData();
+ RHS->clearSubclassOptionalData();
+
++NumLinear;
MadeChange = true;
DEBUG(dbgs() << "Linearized: " << *I << '\n');
@@ -341,6 +347,11 @@
DEBUG(dbgs() << "RA: " << *I << '\n');
I->setOperand(0, Ops[i].Op);
I->setOperand(1, Ops[i+1].Op);
+
+ // Conservatively clear all the optional flags, which may not hold
+ // after the reassociation.
+ I->clearSubclassOptionalData();
+
DEBUG(dbgs() << "TO: " << *I << '\n');
MadeChange = true;
++NumChanged;
@@ -356,6 +367,11 @@
if (I->getOperand(1) != Ops[i].Op) {
DEBUG(dbgs() << "RA: " << *I << '\n');
I->setOperand(1, Ops[i].Op);
+
+ // Conservatively clear all the optional flags, which may not hold
+ // after the reassociation.
+ I->clearSubclassOptionalData();
+
DEBUG(dbgs() << "TO: " << *I << '\n');
MadeChange = true;
++NumChanged;