fix a SCCP miscompilation that could happen when a
forced constant is changed to a constant, we would end
up adding the instruction to the wrong worklist,
preventing it from being properly revisited. This fixes
rdar://7832370
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100837 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SCCP.cpp b/lib/Transforms/Scalar/SCCP.cpp
index 4f09bee..59cdee6 100644
--- a/lib/Transforms/Scalar/SCCP.cpp
+++ b/lib/Transforms/Scalar/SCCP.cpp
@@ -317,7 +317,10 @@
void markConstant(LatticeVal &IV, Value *V, Constant *C) {
if (!IV.markConstant(C)) return;
DEBUG(dbgs() << "markConstant: " << *C << ": " << *V << '\n');
- InstWorkList.push_back(V);
+ if (IV.isOverdefined())
+ OverdefinedInstWorkList.push_back(V);
+ else
+ InstWorkList.push_back(V);
}
void markConstant(Value *V, Constant *C) {
@@ -327,9 +330,13 @@
void markForcedConstant(Value *V, Constant *C) {
assert(!V->getType()->isStructTy() && "Should use other method");
- ValueState[V].markForcedConstant(C);
+ LatticeVal &IV = ValueState[V];
+ IV.markForcedConstant(C);
DEBUG(dbgs() << "markForcedConstant: " << *C << ": " << *V << '\n');
- InstWorkList.push_back(V);
+ if (IV.isOverdefined())
+ OverdefinedInstWorkList.push_back(V);
+ else
+ InstWorkList.push_back(V);
}