Add code for save/restore of callee-saved registers

llvm-svn: 70739

lib/Target/MSP430/MSP430InstrInfo.cpp

@@ -13,6 +13,7 @@
 
 #include "MSP430.h"
 #include "MSP430InstrInfo.h"
+#include "MSP430MachineFunctionInfo.h"
 #include "MSP430TargetMachine.h"
 #include "MSP430GenInstrInfo.inc"
 #include "llvm/Function.h"
@@ -108,3 +109,43 @@ MSP430InstrInfo::isMoveInstr(const MachineInstr& MI,
     return true;
   }
 }
+
+bool
+MSP430InstrInfo::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
+                                           MachineBasicBlock::iterator MI,
+                                const std::vector<CalleeSavedInfo> &CSI) const {
+  if (CSI.empty())
+    return false;
+
+  DebugLoc DL = DebugLoc::getUnknownLoc();
+  if (MI != MBB.end()) DL = MI->getDebugLoc();
+
+  MachineFunction &MF = *MBB.getParent();
+  MSP430MachineFunctionInfo *MFI = MF.getInfo<MSP430MachineFunctionInfo>();
+  MFI->setCalleeSavedFrameSize(CSI.size() * 2);
+
+  for (unsigned i = CSI.size(); i != 0; --i) {
+    unsigned Reg = CSI[i-1].getReg();
+    // Add the callee-saved register as live-in. It's killed at the spill.
+    MBB.addLiveIn(Reg);
+    BuildMI(MBB, MI, DL, get(MSP430::PUSH16r))
+      .addReg(Reg, /*isDef=*/false, /*isImp=*/false, /*isKill=*/true);
+  }
+  return true;
+}
+
+bool
+MSP430InstrInfo::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
+                                             MachineBasicBlock::iterator MI,
+                                const std::vector<CalleeSavedInfo> &CSI) const {
+  if (CSI.empty())
+    return false;
+
+  DebugLoc DL = DebugLoc::getUnknownLoc();
+  if (MI != MBB.end()) DL = MI->getDebugLoc();
+
+  for (unsigned i = 0, e = CSI.size(); i != e; ++i)
+    BuildMI(MBB, MI, DL, get(MSP430::POP16r), CSI[i].getReg());
+
+  return true;
+}

lib/Target/MSP430/MSP430InstrInfo.h

@@ -44,12 +44,21 @@ public:
 
   virtual void storeRegToStackSlot(MachineBasicBlock &MBB,
                                    MachineBasicBlock::iterator MI,
-                                   unsigned SrcReg, bool isKill, int FrameIndex,
+                                   unsigned SrcReg, bool isKill,
+                                   int FrameIndex,
                                    const TargetRegisterClass *RC) const;
   virtual void loadRegFromStackSlot(MachineBasicBlock &MBB,
                                     MachineBasicBlock::iterator MI,
                                     unsigned DestReg, int FrameIdx,
                                     const TargetRegisterClass *RC) const;
+
+  virtual bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
+                                         MachineBasicBlock::iterator MI,
+                                 const std::vector<CalleeSavedInfo> &CSI) const;
+  virtual bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
+                                           MachineBasicBlock::iterator MI,
+                                 const std::vector<CalleeSavedInfo> &CSI) const;
+
 };
 
 }

lib/Target/MSP430/MSP430InstrInfo.td

@@ -116,6 +116,17 @@ let isCall = 1 in
   }
 
 
+//===----------------------------------------------------------------------===//
+//  Miscellaneous Instructions...
+//
+let Defs = [SPW], Uses = [SPW], neverHasSideEffects=1 in {
+let mayLoad = 1 in
+def POP16r   : Pseudo<(outs GR16:$reg), (ins), "pop.w\t$reg", []>;
+
+let mayStore = 1 in
+def PUSH16r  : Pseudo<(outs), (ins GR16:$reg), "push.w\t$reg",[]>;
+}
+
 //===----------------------------------------------------------------------===//
 // Move Instructions
 

lib/Target/MSP430/MSP430MachineFunctionInfo.h

@@ -0,0 +1,39 @@
+//===- MSP430MachineFuctionInfo.h - MSP430 machine function info -*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares MSP430-specific per-machine-function information.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MSP430MACHINEFUNCTIONINFO_H
+#define MSP430MACHINEFUNCTIONINFO_H
+
+#include "llvm/CodeGen/MachineFunction.h"
+
+namespace llvm {
+
+/// MSP430MachineFunctionInfo - This class is derived from MachineFunction and
+/// contains private MSP430 target-specific information for each MachineFunction.
+class MSP430MachineFunctionInfo : public MachineFunctionInfo {
+  /// CalleeSavedFrameSize - Size of the callee-saved register portion of the
+  /// stack frame in bytes.
+  unsigned CalleeSavedFrameSize;
+
+public:
+  MSP430MachineFunctionInfo() : CalleeSavedFrameSize(0) {}
+
+  MSP430MachineFunctionInfo(MachineFunction &MF) : CalleeSavedFrameSize(0) {}
+
+  unsigned getCalleeSavedFrameSize() const { return CalleeSavedFrameSize; }
+  void setCalleeSavedFrameSize(unsigned bytes) { CalleeSavedFrameSize = bytes; }
+};
+
+} // End llvm namespace
+
+#endif