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

7 files changed, 23 insertions, 28 deletions

diff --git a/lib/Target/ARM/ARMBaseRegisterInfo.cpp b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
index baf65115d2..e5b300fc77 100644
--- a/lib/Target/ARM/ARMBaseRegisterInfo.cpp
+++ b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
@@ -84,6 +84,11 @@ ARMBaseRegisterInfo::getCallPreservedMask(CallingConv::ID) const {
     ? CSR_iOS_RegMask : CSR_AAPCS_RegMask;
 }
 
+const uint32_t*
+ARMBaseRegisterInfo::getNoPreservedMask() const {
+  return CSR_NoRegs_RegMask;
+}
+
 BitVector ARMBaseRegisterInfo::
 getReservedRegs(const MachineFunction &MF) const {
   const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
diff --git a/lib/Target/ARM/ARMBaseRegisterInfo.h b/lib/Target/ARM/ARMBaseRegisterInfo.h
index dbbb566900..e2bdd046db 100644
--- a/lib/Target/ARM/ARMBaseRegisterInfo.h
+++ b/lib/Target/ARM/ARMBaseRegisterInfo.h
@@ -96,6 +96,7 @@ public:
   /// Code Generation virtual methods...
   const uint16_t *getCalleeSavedRegs(const MachineFunction *MF = 0) const;
   const uint32_t *getCallPreservedMask(CallingConv::ID) const;
+  const uint32_t *getNoPreservedMask() const;
 
   BitVector getReservedRegs(const MachineFunction &MF) const;
 
diff --git a/lib/Target/ARM/ARMCallingConv.td b/lib/Target/ARM/ARMCallingConv.td
index bda1517685..b378b96626 100644
--- a/lib/Target/ARM/ARMCallingConv.td
+++ b/lib/Target/ARM/ARMCallingConv.td
@@ -190,6 +190,8 @@ def RetCC_ARM_AAPCS_VFP : CallingConv<[
 // Callee-saved register lists.
 //===----------------------------------------------------------------------===//
 
+def CSR_NoRegs : CalleeSavedRegs<(add)>;
+
 def CSR_AAPCS : CalleeSavedRegs<(add LR, R11, R10, R9, R8, R7, R6, R5, R4,
                                      (sequence "D%u", 15, 8))>;
 
diff --git a/lib/Target/ARM/ARMExpandPseudoInsts.cpp b/lib/Target/ARM/ARMExpandPseudoInsts.cpp
index f7c8a9c2dc..8c45e0b98d 100644
--- a/lib/Target/ARM/ARMExpandPseudoInsts.cpp
+++ b/lib/Target/ARM/ARMExpandPseudoInsts.cpp
@@ -777,9 +777,7 @@ bool ARMExpandPseudo::ExpandMI(MachineBasicBlock &MBB,
       MI.eraseFromParent();
       return true;
     }
-    case ARM::Int_eh_sjlj_dispatchsetup:
-    case ARM::Int_eh_sjlj_dispatchsetup_nofp:
-    case ARM::tInt_eh_sjlj_dispatchsetup: {
+    case ARM::Int_eh_sjlj_dispatchsetup: {
       MachineFunction &MF = *MI.getParent()->getParent();
       const ARMBaseInstrInfo *AII =
         static_cast<const ARMBaseInstrInfo*>(TII);
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index ebcec114d2..3b9558bc2a 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
diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index b193a5c033..df2e55ed5c 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -4743,21 +4743,13 @@ def Int_eh_sjlj_longjmp : PseudoInst<(outs), (ins GPR:$src, GPR:$scratch),
                                 Requires<[IsARM, IsIOS]>;
 }
 
-// eh.sjlj.dispatchsetup pseudo-instructions.
-// These pseudos are used for both ARM and Thumb2. Any differences are
-// handled when the pseudo is expanded (which happens before any passes
-// that need the instruction size).
-let Defs =
-  [ R0,  R1,  R2,  R3,  R4,  R5,  R6,  R7,  R8,  R9,  R10, R11, R12, LR, CPSR,
-    Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, Q10, Q11, Q12, Q13, Q14, Q15 ],
-  isBarrier = 1 in
+// eh.sjlj.dispatchsetup pseudo-instruction.
+// This pseudo is used for both ARM and Thumb. Any differences are handled when
+// the pseudo is expanded (which happens before any passes that need the
+// instruction size).
+let isBarrier = 1 in
 def Int_eh_sjlj_dispatchsetup : PseudoInst<(outs), (ins), NoItinerary, []>;
 
-let Defs =
-  [ R0,  R1,  R2,  R3,  R4,  R5,  R6,  R7,  R8,  R9,  R10, R11, R12, LR, CPSR ],
-  isBarrier = 1 in
-def Int_eh_sjlj_dispatchsetup_nofp : PseudoInst<(outs), (ins), NoItinerary, []>;
-
 
 //===----------------------------------------------------------------------===//
 // Non-Instruction Patterns
diff --git a/lib/Target/ARM/ARMInstrThumb.td b/lib/Target/ARM/ARMInstrThumb.td
index a5c0bc6740..ae7a5c00bd 100644
--- a/lib/Target/ARM/ARMInstrThumb.td
+++ b/lib/Target/ARM/ARMInstrThumb.td
@@ -1247,10 +1247,6 @@ def tInt_eh_sjlj_longjmp : XI<(outs), (ins GPR:$src, GPR:$scratch),
                               [(ARMeh_sjlj_longjmp GPR:$src, GPR:$scratch)]>,
                              Requires<[IsThumb, IsIOS]>;
 
-let Defs = [ R0,  R1,  R2,  R3,  R4,  R5,  R6,  R7, R12, CPSR ],
-    isBarrier = 1 in
-def tInt_eh_sjlj_dispatchsetup : PseudoInst<(outs), (ins), NoItinerary, []>;
-
 //===----------------------------------------------------------------------===//
 // Non-Instruction Patterns
 //