Use a SmallPtrSet to dedup successors in EmitSjLjDispatchBlock.

The test case ARM/2011-05-04-MultipleLandingPadSuccs.ll was creating
duplicate successor list entries.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162222 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 3974d057a8dd0d6132e2cbf36a04d2be6e741164..df4039b841342360e6005f003bd8cce509b8e1d5 100644 (file)
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -6151,13 +6151,12 @@ EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const {
   }
 
   // Add the jump table entries as successors to the MBB.
-  MachineBasicBlock *PrevMBB = 0;
+  SmallPtrSet<MachineBasicBlock*, 8> SeenMBBs;
   for (std::vector<MachineBasicBlock*>::iterator
          I = LPadList.begin(), E = LPadList.end(); I != E; ++I) {
     MachineBasicBlock *CurMBB = *I;
-    if (PrevMBB != CurMBB)
+    if (SeenMBBs.insert(CurMBB))
       DispContBB->addSuccessor(CurMBB);
-    PrevMBB = CurMBB;
   }
 
   // N.B. the order the invoke BBs are processed in doesn't matter here.