Don't try to move a MBB into the fall-through position if it's a landing pad or
branches only to a landing pad. Without this check, the compiler would go into
an infinite loop because the branch to a landing pad is an "abnormal" edge which
wasn't being taken into account.
This is the meat of that fix:
if (!PrevBB.canFallThrough() && !MBB->BranchesToLandingPad(MBB)) {
The other stuff is simplification of the "branches to a landing pad" code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91161 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 0097dd1..80b4b0f 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -457,16 +457,9 @@
SmallSet<const MachineBasicBlock*, 32> Visited;
const MachineBasicBlock *CurMBB = MBB;
- while (!Visited.count(CurMBB) && !CurMBB->isLandingPad()) {
- if (CurMBB->size() != 1 || CurMBB->succ_empty() || CurMBB->succ_size() != 1)
- break;
-
- const TargetInstrInfo *TII =
- CurMBB->getParent()->getTarget().getInstrInfo();
- if (!TII->isUnpredicatedTerminator(CurMBB->begin()))
- break;
-
- Visited.insert(CurMBB);
+ while (!CurMBB->isLandingPad()) {
+ if (CurMBB->succ_size() != 1) break;
+ if (!Visited.insert(CurMBB)) break;
CurMBB = *CurMBB->succ_begin();
}