Take all of the invoke basic blocks and make the dispatch basic block their new

successor. Remove the old landing pad from their successor list, because it's
now the successor of the dispatch block. Now that the landing pad blocks are no
longer the destination of invokes, we can mark them as normal basic blocks
instead of landing pads.

This more closely resembles what the CFG is actually doing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141436 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 28 insertions, 4 deletions

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index ab0c558968..0313f99908 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -5699,12 +5699,15 @@ EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const {
 
   // Get an ordered list of the machine basic blocks for the jump table.
   std::vector<MachineBasicBlock*> LPadList;
+  SmallPtrSet<MachineBasicBlock*, 64> InvokeBBs;
   LPadList.reserve(CallSiteNumToLPad.size());
   for (unsigned I = 1; I <= MaxCSNum; ++I) {
     SmallVectorImpl<MachineBasicBlock*> &MBBList = CallSiteNumToLPad[I];
     for (SmallVectorImpl<MachineBasicBlock*>::iterator
-           II = MBBList.begin(), IE = MBBList.end(); II != IE; ++II)
+           II = MBBList.begin(), IE = MBBList.end(); II != IE; ++II) {
       LPadList.push_back(*II);
+      InvokeBBs.insert((*II)->pred_begin(), (*II)->pred_end());
+    }
   }
 
   assert(!LPadList.empty() &&
@@ -5721,7 +5724,6 @@ EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const {
   // Shove the dispatch's address into the return slot in the function context.
   MachineBasicBlock *DispatchBB = MF->CreateMachineBasicBlock();
   DispatchBB->setIsLandingPad();
-  MBB->addSuccessor(DispatchBB);
 
   MachineBasicBlock *TrapBB = MF->CreateMachineBasicBlock();
   BuildMI(TrapBB, dl, TII->get(Subtarget->isThumb() ? ARM::tTRAP : ARM::TRAP));
@@ -5873,9 +5875,31 @@ EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const {
   }
 
   // Add the jump table entries as successors to the MBB.
+  MachineBasicBlock *PrevMBB = 0;
   for (std::vector<MachineBasicBlock*>::iterator
-         I = LPadList.begin(), E = LPadList.end(); I != E; ++I)
-    DispContBB->addSuccessor(*I);
+         I = LPadList.begin(), E = LPadList.end(); I != E; ++I) {
+    MachineBasicBlock *CurMBB = *I;
+    if (PrevMBB != CurMBB)
+      DispContBB->addSuccessor(CurMBB);
+    PrevMBB = CurMBB;
+  }
+
+  // Remove the landing pad successor from the invoke block and replace it with
+  // the new dispatch block.
+  for (SmallPtrSet<MachineBasicBlock*, 64>::iterator
+         I = InvokeBBs.begin(), E = InvokeBBs.end(); I != E; ++I) {
+    MachineBasicBlock *BB = *I;
+    for (MachineBasicBlock::succ_iterator
+           SI = BB->succ_begin(), SE = BB->succ_end(); SI != SE; ++SI) {
+      MachineBasicBlock *SMBB = *SI;
+      if (SMBB->isLandingPad()) {
+        BB->removeSuccessor(SMBB);
+        SMBB->setIsLandingPad(false);
+      }
+    }
+
+    BB->addSuccessor(DispatchBB);
+  }
 
   // The instruction is gone now.
   MI->eraseFromParent();