Mark the Int_eh_sjlj_dispatchsetup pseudo instruction as clobbering all

registers.  Previously, the register we being marked as implicitly defined, but
not killed.  In some cases this would cause the register scavenger to spill a
dead register.

Also, use an empty register mask to simplify the logic and to reduce the memory
footprint.
rdar://12592448

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167499 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 9 insertions, 8 deletions

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index ebcec11..3b9558b 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -6077,12 +6077,15 @@ EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const {
                              MachineMemOperand::MOLoad |
                              MachineMemOperand::MOVolatile, 4, 4);
 
-  if (AFI->isThumb1OnlyFunction())
-    BuildMI(DispatchBB, dl, TII->get(ARM::tInt_eh_sjlj_dispatchsetup));
-  else if (!Subtarget->hasVFP2())
-    BuildMI(DispatchBB, dl, TII->get(ARM::Int_eh_sjlj_dispatchsetup_nofp));
-  else
-    BuildMI(DispatchBB, dl, TII->get(ARM::Int_eh_sjlj_dispatchsetup));
+  MachineInstrBuilder MIB;
+  MIB = BuildMI(DispatchBB, dl, TII->get(ARM::Int_eh_sjlj_dispatchsetup));
+
+  const ARMBaseInstrInfo *AII = static_cast<const ARMBaseInstrInfo*>(TII);
+  const ARMBaseRegisterInfo &RI = AII->getRegisterInfo();
+
+  // Add a register mask with no preserved registers.  This results in all
+  // registers being marked as clobbered.
+  MIB.addRegMask(RI.getNoPreservedMask());
 
   unsigned NumLPads = LPadList.size();
   if (Subtarget->isThumb2()) {
@@ -6301,8 +6304,6 @@ EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const {
   }
 
   // N.B. the order the invoke BBs are processed in doesn't matter here.
-  const ARMBaseInstrInfo *AII = static_cast<const ARMBaseInstrInfo*>(TII);
-  const ARMBaseRegisterInfo &RI = AII->getRegisterInfo();
   const uint16_t *SavedRegs = RI.getCalleeSavedRegs(MF);
   SmallVector<MachineBasicBlock*, 64> MBBLPads;
   for (SmallPtrSet<MachineBasicBlock*, 64>::iterator