Inform LazyValueInfo whenever a block is deleted, to avoid dangling pointer issues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111382 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp
index b17f80d..2c3c39b 100644
--- a/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/lib/Transforms/Scalar/JumpThreading.cpp
@@ -147,6 +147,7 @@
DEBUG(dbgs() << " JT: Deleting dead block '" << BB->getName()
<< "' with terminator: " << *BB->getTerminator() << '\n');
LoopHeaders.erase(BB);
+ if (LVI) LVI->eraseBlock(BB);
DeleteDeadBlock(BB);
Changed = true;
} else if (BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator())) {
@@ -167,6 +168,11 @@
bool ErasedFromLoopHeaders = LoopHeaders.erase(BB);
BasicBlock *Succ = BI->getSuccessor(0);
+ // FIXME: It is always conservatively correct to drop the info
+ // for a block even if it doesn't get erased. This isn't totally
+ // awesome, but it allows us to use AssertingVH to prevent nasty
+ // dangling pointer issues within LazyValueInfo.
+ if (LVI) LVI->eraseBlock(BB);
if (TryToSimplifyUncondBranchFromEmptyBlock(BB)) {
Changed = true;
// If we deleted BB and BB was the header of a loop, then the
@@ -489,6 +495,7 @@
// Remember if SinglePred was the entry block of the function. If so, we
// will need to move BB back to the entry position.
bool isEntry = SinglePred == &SinglePred->getParent()->getEntryBlock();
+ if (LVI) LVI->eraseBlock(SinglePred);
MergeBasicBlockIntoOnlyPred(BB);
if (isEntry && BB != &BB->getParent()->getEntryBlock())