[llvm-commits] [llvm] r141436 - /llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp

[Bill Wendling]

Author: void
Date: Fri Oct  7 18:18:02 2011
New Revision: 141436

URL: http://llvm.org/viewvc/llvm-project?rev=141436&view=rev
Log:
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.

Modified:
    llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp

Modified: llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp?rev=141436&r1=141435&r2=141436&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp Fri Oct  7 18:18:02 2011
@@ -5699,12 +5699,15 @@
 
   // 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 @@
   // 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 @@
   }
 
   // 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();