Vendor import of llvm release_30 branch r142614:

http://llvm.org/svn/llvm-project/llvm/branches/release_30@142614

1 files changed, 12 insertions, 1 deletions

diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index 6d6244e..d879378 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -177,6 +177,10 @@ char &llvm::TwoAddressInstructionPassID = TwoAddressInstructionPass::ID;
 bool TwoAddressInstructionPass::Sink3AddrInstruction(MachineBasicBlock *MBB,
                                            MachineInstr *MI, unsigned SavedReg,
                                            MachineBasicBlock::iterator OldPos) {
+  // FIXME: Shouldn't we be trying to do this before we three-addressify the
+  // instruction?  After this transformation is done, we no longer need
+  // the instruction to be in three-address form.
+
   // Check if it's safe to move this instruction.
   bool SeenStore = true; // Be conservative.
   if (!MI->isSafeToMove(TII, AA, SeenStore))
@@ -217,7 +221,11 @@ bool TwoAddressInstructionPass::Sink3AddrInstruction(MachineBasicBlock *MBB,
     break;
   }
 
-  if (!KillMI || KillMI->getParent() != MBB || KillMI == MI)
+  // If we find the instruction that kills SavedReg, and it is in an
+  // appropriate location, we can try to sink the current instruction
+  // past it.
+  if (!KillMI || KillMI->getParent() != MBB || KillMI == MI ||
+      KillMI->getDesc().isTerminator())
     return false;
 
   // If any of the definitions are used by another instruction between the
@@ -1041,6 +1049,9 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) {
   DEBUG(dbgs() << "********** Function: " 
         << MF.getFunction()->getName() << '\n');
 
+  // This pass takes the function out of SSA form.
+  MRI->leaveSSA();
+
   // ReMatRegs - Keep track of the registers whose def's are remat'ed.
   BitVector ReMatRegs(MRI->getNumVirtRegs());