Fix llvm::removeUnreachableBlocks to handle unreachable loops.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177713 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index a54ee08..be80d34 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -985,22 +985,17 @@
if (Reachable.count(I))
continue;
- // Remove the block as predecessor of all its reachable successors.
- // Unreachable successors don't matter as they'll soon be removed, too.
for (succ_iterator SI = succ_begin(I), SE = succ_end(I); SI != SE; ++SI)
if (Reachable.count(*SI))
(*SI)->removePredecessor(I);
-
- // Zap all instructions in this basic block.
- while (!I->empty()) {
- Instruction &Inst = I->back();
- if (!Inst.use_empty())
- Inst.replaceAllUsesWith(UndefValue::get(Inst.getType()));
- I->getInstList().pop_back();
- }
-
- --I;
- llvm::next(I)->eraseFromParent();
+ I->dropAllReferences();
}
+
+ for (Function::iterator I = llvm::next(F.begin()), E=F.end(); I != E;)
+ if (!Reachable.count(I))
+ I = F.getBasicBlockList().erase(I);
+ else
+ ++I;
+
return true;
}