Address comments on last patch:
- Loosen the restrictions when checking of it branches to a landing pad.
- Make the loop more efficient by checking the '.insert' return value.
- Do cheaper checks first.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91101 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 684af34..7ce723e 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -449,24 +449,19 @@
addSuccessor(New);
}
-/// BranchesToLandingPad - The basic block branches only to a landing pad or to
-/// another basic block which branches only to a landing pad. No other
-/// instructions are present other than the unconditional branch.
+/// BranchesToLandingPad - The basic block is a landing pad or branches only to
+/// a landing pad. No other instructions are present other than the
+/// unconditional branch.
bool
MachineBasicBlock::BranchesToLandingPad(const MachineBasicBlock *MBB) const {
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)
+ while (!CurMBB->isLandingPad()) {
+ if (CurMBB->succ_size() != 1)
break;
- const TargetInstrInfo *TII =
- CurMBB->getParent()->getTarget().getInstrInfo();
- if (!TII->isUnpredicatedTerminator(CurMBB->begin()))
- break;
-
- Visited.insert(CurMBB);
+ if (!Visited.insert(CurMBB)) break;
CurMBB = *CurMBB->succ_begin();
}
@@ -516,8 +511,8 @@
} else if (MBB == DestB) {
DestB = 0;
++SI;
- } else if (BranchesToLandingPad(MBB) &&
- MBB != OrigDestA && MBB != OrigDestB) {
+ } else if (MBB != OrigDestA && MBB != OrigDestB &&
+ BranchesToLandingPad(MBB)) {
++SI;
} else {
// Otherwise, this is a superfluous edge, remove it.