Remove dead blocks in the end.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63880 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/CondPropagate.cpp b/lib/Transforms/Scalar/CondPropagate.cpp
index 1b75517..000ef60 100644
--- a/lib/Transforms/Scalar/CondPropagate.cpp
+++ b/lib/Transforms/Scalar/CondPropagate.cpp
@@ -23,6 +23,7 @@
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Streams.h"
using namespace llvm;
@@ -44,6 +45,7 @@
private:
bool MadeChange;
+ SmallVector<BasicBlock *, 4> DeadBlocks;
void SimplifyBlock(BasicBlock *BB);
void SimplifyPredecessors(BranchInst *BI);
void SimplifyPredecessors(SwitchInst *SI);
@@ -60,14 +62,22 @@
bool CondProp::runOnFunction(Function &F) {
bool EverMadeChange = false;
+ DeadBlocks.clear();
// While we are simplifying blocks, keep iterating.
do {
MadeChange = false;
- for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
- SimplifyBlock(BB);
+ for (Function::iterator BB = F.begin(), E = F.end(); BB != E;)
+ SimplifyBlock(BB++);
EverMadeChange = EverMadeChange || MadeChange;
} while (MadeChange);
+
+ if (EverMadeChange) {
+ while (!DeadBlocks.empty()) {
+ BasicBlock *BB = DeadBlocks.back(); DeadBlocks.pop_back();
+ DeleteDeadBlock(BB);
+ }
+ }
return EverMadeChange;
}
@@ -111,8 +121,9 @@
// Succ is now dead, but we cannot delete it without potentially
// invalidating iterators elsewhere. Just insert an unreachable
- // instruction in it.
+ // instruction in it and delete this block later on.
new UnreachableInst(Succ);
+ DeadBlocks.push_back(Succ);
MadeChange = true;
}
}