1 files changed, 41 insertions, 3 deletions

diff --git a/lib/Target/ARM/Thumb1FrameLowering.cpp b/lib/Target/ARM/Thumb1FrameLowering.cpp
index 123ada6..2c3388c 100644
--- a/lib/Target/ARM/Thumb1FrameLowering.cpp
+++ b/lib/Target/ARM/Thumb1FrameLowering.cpp
@@ -43,6 +43,41 @@ emitSPUpdate(MachineBasicBlock &MBB,
                             MRI, MIFlags);
 }
 
+
+void Thumb1FrameLowering::
+eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
+                              MachineBasicBlock::iterator I) const {
+  const Thumb1InstrInfo &TII =
+    *static_cast<const Thumb1InstrInfo*>(MF.getTarget().getInstrInfo());
+  const Thumb1RegisterInfo *RegInfo =
+    static_cast<const Thumb1RegisterInfo*>(MF.getTarget().getRegisterInfo());
+  if (!hasReservedCallFrame(MF)) {
+    // If we have alloca, convert as follows:
+    // ADJCALLSTACKDOWN -> sub, sp, sp, amount
+    // ADJCALLSTACKUP   -> add, sp, sp, amount
+    MachineInstr *Old = I;
+    DebugLoc dl = Old->getDebugLoc();
+    unsigned Amount = Old->getOperand(0).getImm();
+    if (Amount != 0) {
+      // We need to keep the stack aligned properly.  To do this, we round the
+      // amount of space needed for the outgoing arguments up to the next
+      // alignment boundary.
+      unsigned Align = getStackAlignment();
+      Amount = (Amount+Align-1)/Align*Align;
+
+      // Replace the pseudo instruction with a new instruction...
+      unsigned Opc = Old->getOpcode();
+      if (Opc == ARM::ADJCALLSTACKDOWN || Opc == ARM::tADJCALLSTACKDOWN) {
+        emitSPUpdate(MBB, I, TII, dl, *RegInfo, -Amount);
+      } else {
+        assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP);
+        emitSPUpdate(MBB, I, TII, dl, *RegInfo, Amount);
+      }
+    }
+  }
+  MBB.erase(I);
+}
+
 void Thumb1FrameLowering::emitPrologue(MachineFunction &MF) const {
   MachineBasicBlock &MBB = MF.front();
   MachineBasicBlock::iterator MBBI = MBB.begin();
@@ -124,14 +159,17 @@ void Thumb1FrameLowering::emitPrologue(MachineFunction &MF) const {
   unsigned DPRCSOffset  = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
   unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
   unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
-  AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) + NumBytes);
+  bool HasFP = hasFP(MF);
+  if (HasFP)
+    AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) +
+                                NumBytes);
   AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
   AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
   AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
   NumBytes = DPRCSOffset;
 
   // Adjust FP so it point to the stack slot that contains the previous FP.
-  if (hasFP(MF)) {
+  if (HasFP) {
     AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tADDrSPi), FramePtr)
       .addFrameIndex(FramePtrSpillFI).addImm(0)
       .setMIFlags(MachineInstr::FrameSetup));
@@ -146,7 +184,7 @@ void Thumb1FrameLowering::emitPrologue(MachineFunction &MF) const {
     emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -NumBytes,
                  MachineInstr::FrameSetup);
 
-  if (STI.isTargetELF() && hasFP(MF))
+  if (STI.isTargetELF() && HasFP)
     MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
                              AFI->getFramePtrSpillOffset());