From: Bill Wendling <isanbard@gmail.com>
Date: Tue, 18 Oct 2011 18:30:49 +0000 (+0000)
Subject: A landing pad could have more than one predecessor. In that case, we want that
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=f7b0207f1e89f08b2e2d233b8cc6ba6fcb2a0f4d;p=oota-llvm.git

A landing pad could have more than one predecessor. In that case, we want that
predecessor to remove the jump to it as well. Delay clearing the 'landing pad'
flag until after the jumps have been removed. (There is an implicit assumption
in several modules that an MBB which jumps to a landing pad has only two
successors.)
<rdar://problem/10304224>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142390 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 77530067748..6447001f715 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -5895,6 +5895,7 @@ EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const {
   const ARMBaseInstrInfo *AII = static_cast<const ARMBaseInstrInfo*>(TII);
   const ARMBaseRegisterInfo &RI = AII->getRegisterInfo();
   const unsigned *SavedRegs = RI.getCalleeSavedRegs(MF);
+  SmallVector<MachineBasicBlock*, 64> MBBLPads;
   for (SmallPtrSet<MachineBasicBlock*, 64>::iterator
          I = InvokeBBs.begin(), E = InvokeBBs.end(); I != E; ++I) {
     MachineBasicBlock *BB = *I;
@@ -5906,7 +5907,7 @@ EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const {
       MachineBasicBlock *SMBB = *SI;
       if (SMBB->isLandingPad()) {
         BB->removeSuccessor(SMBB);
-        SMBB->setIsLandingPad(false);
+        MBBLPads.push_back(SMBB);
       }
     }
 
@@ -5940,6 +5941,12 @@ EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const {
     }
   }
 
+  // Mark all former landing pads as non-landing pads. The dispatch is the only
+  // landing pad now.
+  for (SmallVectorImpl<MachineBasicBlock*>::iterator
+         I = MBBLPads.begin(), E = MBBLPads.end(); I != E; ++I)
+    (*I)->setIsLandingPad(false);
+
   // The instruction is gone now.
   MI->eraseFromParent();