Move callee-saved regs spills / reloads to TFI

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120228 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 79 insertions, 0 deletions

diff --git a/lib/Target/ARM/Thumb1FrameInfo.cpp b/lib/Target/ARM/Thumb1FrameInfo.cpp
index bb1faf576e..d92d83c4e4 100644
--- a/lib/Target/ARM/Thumb1FrameInfo.cpp
+++ b/lib/Target/ARM/Thumb1FrameInfo.cpp
@@ -264,3 +264,82 @@ void Thumb1FrameInfo::emitEpilogue(MachineFunction &MF,
     MBB.erase(MBBI);
   }
 }
+
+bool Thumb1FrameInfo::
+spillCalleeSavedRegisters(MachineBasicBlock &MBB,
+                          MachineBasicBlock::iterator MI,
+                          const std::vector<CalleeSavedInfo> &CSI,
+                          const TargetRegisterInfo *TRI) const {
+  if (CSI.empty())
+    return false;
+
+  DebugLoc DL;
+  MachineFunction &MF = *MBB.getParent();
+  const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+
+  if (MI != MBB.end()) DL = MI->getDebugLoc();
+
+  MachineInstrBuilder MIB = BuildMI(MBB, MI, DL, TII.get(ARM::tPUSH));
+  AddDefaultPred(MIB);
+  for (unsigned i = CSI.size(); i != 0; --i) {
+    unsigned Reg = CSI[i-1].getReg();
+    bool isKill = true;
+
+    // Add the callee-saved register as live-in unless it's LR and
+    // @llvm.returnaddress is called. If LR is returned for @llvm.returnaddress
+    // then it's already added to the function and entry block live-in sets.
+    if (Reg == ARM::LR) {
+      MachineFunction &MF = *MBB.getParent();
+      if (MF.getFrameInfo()->isReturnAddressTaken() &&
+          MF.getRegInfo().isLiveIn(Reg))
+        isKill = false;
+    }
+
+    if (isKill)
+      MBB.addLiveIn(Reg);
+
+    MIB.addReg(Reg, getKillRegState(isKill));
+  }
+  return true;
+}
+
+bool Thumb1FrameInfo::
+restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
+                            MachineBasicBlock::iterator MI,
+                            const std::vector<CalleeSavedInfo> &CSI,
+                            const TargetRegisterInfo *TRI) const {
+  if (CSI.empty())
+    return false;
+
+  MachineFunction &MF = *MBB.getParent();
+  ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
+  const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+
+  bool isVarArg = AFI->getVarArgsRegSaveSize() > 0;
+  DebugLoc DL = MI->getDebugLoc();
+  MachineInstrBuilder MIB = BuildMI(MF, DL, TII.get(ARM::tPOP));
+  AddDefaultPred(MIB);
+
+  bool NumRegs = false;
+  for (unsigned i = CSI.size(); i != 0; --i) {
+    unsigned Reg = CSI[i-1].getReg();
+    if (Reg == ARM::LR) {
+      // Special epilogue for vararg functions. See emitEpilogue
+      if (isVarArg)
+        continue;
+      Reg = ARM::PC;
+      (*MIB).setDesc(TII.get(ARM::tPOP_RET));
+      MI = MBB.erase(MI);
+    }
+    MIB.addReg(Reg, getDefRegState(true));
+    NumRegs = true;
+  }
+
+  // It's illegal to emit pop instruction without operands.
+  if (NumRegs)
+    MBB.insert(MI, &*MIB);
+  else
+    MF.DeleteMachineInstr(MIB);
+
+  return true;
+}