Turn off critical edge splitting for landing pads. The introduction of a
non-landing pad basic block as the successor to a block that ends in an
unconditional jump will cause block folding to remove the added block as a
successor. Thus eventually removing it AND the landing pad entirely. Critical
edge splitting is an optimization, so we can safely turn it off when dealing
with landing pads.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91634 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/PHIElimination.cpp b/lib/CodeGen/PHIElimination.cpp
index d11e01a..58c3dec 100644
--- a/lib/CodeGen/PHIElimination.cpp
+++ b/lib/CodeGen/PHIElimination.cpp
@@ -71,7 +71,7 @@
Changed |= EliminatePHINodes(Fn, *I);
// Remove dead IMPLICIT_DEF instructions.
- for (SmallPtrSet<MachineInstr*,4>::iterator I = ImpDefs.begin(),
+ for (SmallPtrSet<MachineInstr*, 4>::iterator I = ImpDefs.begin(),
E = ImpDefs.end(); I != E; ++I) {
MachineInstr *DefMI = *I;
unsigned DefReg = DefMI->getOperand(0).getReg();
@@ -83,8 +83,8 @@
for (LoweredPHIMap::iterator I = LoweredPHIs.begin(), E = LoweredPHIs.end();
I != E; ++I)
Fn.DeleteMachineInstr(I->first);
- LoweredPHIs.clear();
+ LoweredPHIs.clear();
ImpDefs.clear();
VRegPHIUseCount.clear();
return Changed;
@@ -384,7 +384,8 @@
bool llvm::PHIElimination::SplitPHIEdges(MachineFunction &MF,
MachineBasicBlock &MBB,
LiveVariables &LV) {
- if (MBB.empty() || MBB.front().getOpcode() != TargetInstrInfo::PHI)
+ if (MBB.empty() || MBB.front().getOpcode() != TargetInstrInfo::PHI ||
+ MBB.isLandingPad())
return false; // Quick exit for basic blocks without PHIs.
for (MachineBasicBlock::const_iterator BBI = MBB.begin(), BBE = MBB.end();