[BDCE] Skip metadata while replacing uses.
The fix committed in r288851 doesn't cover all the cases.
In particular, if we have an instruction with side effects
which has a no non-dbg use not depending on the bits, we still
perform RAUW destroying the dbg.value's first argument.
Prevent metadata from being replaced here to avoid the issue.
Differential Revision: https://reviews.llvm.org/D27534
llvm-svn: 288987
diff --git a/llvm/lib/IR/Value.cpp b/llvm/lib/IR/Value.cpp
index 451cb09..91a999b 100644
--- a/llvm/lib/IR/Value.cpp
+++ b/llvm/lib/IR/Value.cpp
@@ -367,7 +367,7 @@
}
#endif // NDEBUG
-void Value::replaceAllUsesWith(Value *New) {
+void Value::doRAUW(Value *New, bool NoMetadata) {
assert(New && "Value::replaceAllUsesWith(<null>) is invalid!");
assert(!contains(New, this) &&
"this->replaceAllUsesWith(expr(this)) is NOT valid!");
@@ -377,7 +377,7 @@
// Notify all ValueHandles (if present) that this value is going away.
if (HasValueHandle)
ValueHandleBase::ValueIsRAUWd(this, New);
- if (isUsedByMetadata())
+ if (!NoMetadata && isUsedByMetadata())
ValueAsMetadata::handleRAUW(this, New);
while (!use_empty()) {
@@ -398,6 +398,14 @@
BB->replaceSuccessorsPhiUsesWith(cast<BasicBlock>(New));
}
+void Value::replaceAllUsesWith(Value *New) {
+ doRAUW(New, false /* NoMetadata */);
+}
+
+void Value::replaceNonMetadataUsesWith(Value *New) {
+ doRAUW(New, true /* NoMetadata */);
+}
+
// Like replaceAllUsesWith except it does not handle constants or basic blocks.
// This routine leaves uses within BB.
void Value::replaceUsesOutsideBlock(Value *New, BasicBlock *BB) {