--- a/lib/Target/Mips/Mips16InstrInfo.cpp	Thu Dec 12 15:22:36 2013 +0900
+++ b/lib/Target/Mips/Mips16InstrInfo.cpp	Mon Sep 08 22:06:00 2014 +0900
@@ -29,10 +29,10 @@
 
 using namespace llvm;
 
+#define DEBUG_TYPE "mips16-instrinfo"
 
-Mips16InstrInfo::Mips16InstrInfo(MipsTargetMachine &tm)
-  : MipsInstrInfo(tm, Mips::Bimm16),
-    RI(*tm.getSubtargetImpl()) {}
+Mips16InstrInfo::Mips16InstrInfo(const MipsSubtarget &STI)
+    : MipsInstrInfo(STI, Mips::Bimm16), RI(STI) {}
 
 const MipsRegisterInfo &Mips16InstrInfo::getRegisterInfo() const {
   return RI;
@@ -43,9 +43,8 @@
 /// the destination along with the FrameIndex of the loaded stack slot.  If
 /// not, return 0.  This predicate must return 0 if the instruction has
 /// any side effects other than loading from the stack slot.
-unsigned Mips16InstrInfo::
-isLoadFromStackSlot(const MachineInstr *MI, int &FrameIndex) const
-{
+unsigned Mips16InstrInfo::isLoadFromStackSlot(const MachineInstr *MI,
+                                              int &FrameIndex) const {
   return 0;
 }
 
@@ -54,9 +53,8 @@
 /// the source reg along with the FrameIndex of the loaded stack slot.  If
 /// not, return 0.  This predicate must return 0 if the instruction has
 /// any side effects other than storing to the stack slot.
-unsigned Mips16InstrInfo::
-isStoreToStackSlot(const MachineInstr *MI, int &FrameIndex) const
-{
+unsigned Mips16InstrInfo::isStoreToStackSlot(const MachineInstr *MI,
+                                             int &FrameIndex) const {
   return 0;
 }
 
@@ -92,11 +90,12 @@
     MIB.addReg(SrcReg, getKillRegState(KillSrc));
 }
 
-void Mips16InstrInfo::
-storeRegToStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
-                unsigned SrcReg, bool isKill, int FI,
-                const TargetRegisterClass *RC, const TargetRegisterInfo *TRI,
-                int64_t Offset) const {
+void Mips16InstrInfo::storeRegToStack(MachineBasicBlock &MBB,
+                                      MachineBasicBlock::iterator I,
+                                      unsigned SrcReg, bool isKill, int FI,
+                                      const TargetRegisterClass *RC,
+                                      const TargetRegisterInfo *TRI,
+                                      int64_t Offset) const {
   DebugLoc DL;
   if (I != MBB.end()) DL = I->getDebugLoc();
   MachineMemOperand *MMO = GetMemOperand(MBB, FI, MachineMemOperand::MOStore);
@@ -109,10 +108,12 @@
       .addMemOperand(MMO);
 }
 
-void Mips16InstrInfo::
-loadRegFromStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
-                 unsigned DestReg, int FI, const TargetRegisterClass *RC,
-                 const TargetRegisterInfo *TRI, int64_t Offset) const {
+void Mips16InstrInfo::loadRegFromStack(MachineBasicBlock &MBB,
+                                       MachineBasicBlock::iterator I,
+                                       unsigned DestReg, int FI,
+                                       const TargetRegisterClass *RC,
+                                       const TargetRegisterInfo *TRI,
+                                       int64_t Offset) const {
   DebugLoc DL;
   if (I != MBB.end()) DL = I->getDebugLoc();
   MachineMemOperand *MMO = GetMemOperand(MBB, FI, MachineMemOperand::MOLoad);
@@ -169,35 +170,58 @@
   return 0;
 }
 
+static void addSaveRestoreRegs(MachineInstrBuilder &MIB,
+                               const std::vector<CalleeSavedInfo> &CSI,
+                               unsigned Flags = 0) {
+  for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
+    // Add the callee-saved register as live-in. Do not add if the register is
+    // RA and return address is taken, because it has already been added in
+    // method MipsTargetLowering::LowerRETURNADDR.
+    // It's killed at the spill, unless the register is RA and return address
+    // is taken.
+    unsigned Reg = CSI[e-i-1].getReg();
+    switch (Reg) {
+    case Mips::RA:
+    case Mips::S0:
+    case Mips::S1:
+      MIB.addReg(Reg, Flags);
+      break;
+    case Mips::S2:
+      break;
+    default:
+      llvm_unreachable("unexpected mips16 callee saved register");
+
+    }
+  }
+}
 // Adjust SP by FrameSize bytes. Save RA, S0, S1
 void Mips16InstrInfo::makeFrame(unsigned SP, int64_t FrameSize,
-                    MachineBasicBlock &MBB,
-                    MachineBasicBlock::iterator I) const {
+                                MachineBasicBlock &MBB,
+                                MachineBasicBlock::iterator I) const {
   DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
-  const BitVector Reserved = RI.getReservedRegs(*MBB.getParent());
+  MachineFunction &MF = *MBB.getParent();
+  MachineFrameInfo *MFI    = MF.getFrameInfo();
+  const BitVector Reserved = RI.getReservedRegs(MF);
   bool SaveS2 = Reserved[Mips::S2];
   MachineInstrBuilder MIB;
   unsigned Opc = ((FrameSize <= 128) && !SaveS2)? Mips::Save16:Mips::SaveX16;
+  MIB = BuildMI(MBB, I, DL, get(Opc));
+  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+  addSaveRestoreRegs(MIB, CSI);
+  if (SaveS2)
+    MIB.addReg(Mips::S2);
   if (isUInt<11>(FrameSize))
-    MIB = BuildMI(
-            MBB, I, DL, get(Opc)).addReg(Mips::RA).
-            addReg(Mips::S0).
-            addReg(Mips::S1).addImm(FrameSize);
+    MIB.addImm(FrameSize);
   else {
     int Base = 2040; // should create template function like isUInt that
                      // returns largest possible n bit unsigned integer
     int64_t Remainder = FrameSize - Base;
-    MIB = BuildMI(
-            MBB, I, DL, get(Opc)).addReg(Mips::RA).
-            addReg(Mips::S0).
-            addReg(Mips::S1).addImm(Base);
+    MIB.addImm(Base);
     if (isInt<16>(-Remainder))
       BuildAddiuSpImm(MBB, I, -Remainder);
     else
       adjustStackPtrBig(SP, -Remainder, MBB, I, Mips::V0, Mips::V1);
   }
-  if (SaveS2)
-    MIB.addReg(Mips::S2);
 }
 
 // Adjust SP by FrameSize bytes. Restore RA, S0, S1
@@ -205,35 +229,31 @@
                                    MachineBasicBlock &MBB,
                                    MachineBasicBlock::iterator I) const {
   DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
-  const BitVector Reserved = RI.getReservedRegs(*MBB.getParent());
+  MachineFunction *MF = MBB.getParent();
+  MachineFrameInfo *MFI    = MF->getFrameInfo();
+  const BitVector Reserved = RI.getReservedRegs(*MF);
   bool SaveS2 = Reserved[Mips::S2];
   MachineInstrBuilder MIB;
   unsigned Opc = ((FrameSize <= 128) && !SaveS2)?
     Mips::Restore16:Mips::RestoreX16;
-  if (isUInt<11>(FrameSize))
-    MIB = BuildMI(
-            MBB, I, DL, get(Opc)).
-            addReg(Mips::RA, RegState::Define).
-            addReg(Mips::S0, RegState::Define).
-            addReg(Mips::S1, RegState::Define).
-            addImm(FrameSize);
-  else {
-    int Base = 2040; // should create template function like isUInt that
+
+  if (!isUInt<11>(FrameSize)) {
+    unsigned Base = 2040;
+    int64_t Remainder = FrameSize - Base;
+    FrameSize = Base; // should create template function like isUInt that
                      // returns largest possible n bit unsigned integer
-    int64_t Remainder = FrameSize - Base;
+
     if (isInt<16>(Remainder))
       BuildAddiuSpImm(MBB, I, Remainder);
     else
       adjustStackPtrBig(SP, Remainder, MBB, I, Mips::A0, Mips::A1);
-    MIB = BuildMI(
-            MBB, I, DL, get(Opc)).
-            addReg(Mips::RA, RegState::Define).
-            addReg(Mips::S0, RegState::Define).
-            addReg(Mips::S1, RegState::Define).
-            addImm(Base);
   }
+  MIB = BuildMI(MBB, I, DL, get(Opc));
+  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+  addSaveRestoreRegs(MIB, CSI, RegState::Define);
   if (SaveS2)
     MIB.addReg(Mips::S2, RegState::Define);
+  MIB.addImm(FrameSize);
 }
 
 // Adjust SP by Amount bytes where bytes can be up to 32bit number.
@@ -246,9 +266,6 @@
                                         MachineBasicBlock::iterator I,
                                         unsigned Reg1, unsigned Reg2) const {
   DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
-//  MachineRegisterInfo &RegInfo = MBB.getParent()->getRegInfo();
-//  unsigned Reg1 = RegInfo.createVirtualRegister(&Mips::CPU16RegsRegClass);
-//  unsigned Reg2 = RegInfo.createVirtualRegister(&Mips::CPU16RegsRegClass);
   //
   // li reg1, constant
   // move reg2, sp
@@ -268,9 +285,9 @@
   MIB4.addReg(Reg1, RegState::Kill);
 }
 
-void Mips16InstrInfo::adjustStackPtrBigUnrestricted(unsigned SP, int64_t Amount,
-                    MachineBasicBlock &MBB,
-                    MachineBasicBlock::iterator I) const {
+void Mips16InstrInfo::adjustStackPtrBigUnrestricted(
+    unsigned SP, int64_t Amount, MachineBasicBlock &MBB,
+    MachineBasicBlock::iterator I) const {
    assert(false && "adjust stack pointer amount exceeded");
 }
 
@@ -286,11 +303,10 @@
 
 /// This function generates the sequence of instructions needed to get the
 /// result of adding register REG and immediate IMM.
-unsigned
-Mips16InstrInfo::loadImmediate(unsigned FrameReg,
-                               int64_t Imm, MachineBasicBlock &MBB,
-                               MachineBasicBlock::iterator II, DebugLoc DL,
-                               unsigned &NewImm) const {
+unsigned Mips16InstrInfo::loadImmediate(unsigned FrameReg, int64_t Imm,
+                                        MachineBasicBlock &MBB,
+                                        MachineBasicBlock::iterator II,
+                                        DebugLoc DL, unsigned &NewImm) const {
   //
   // given original instruction is:
   // Instr rx, T[offset] where offset is too big.
@@ -326,7 +342,7 @@
         !TargetRegisterInfo::isVirtualRegister(MO.getReg()))
       Candidates.reset(MO.getReg());
   }
-  //
+
   // If the same register was used and defined in an instruction, then
   // it will not be in the list of candidates.
   //
@@ -335,7 +351,6 @@
   // present as an operand of the instruction. this tells
   // whether the register is live before the instruction. if it's not
   // then we don't need to save it in case there are no free registers.
-  //
   int DefReg = 0;
   for (unsigned i = 0, e = II->getNumOperands(); i != e; ++i) {
     MachineOperand &MO = II->getOperand(i);
@@ -344,9 +359,8 @@
       break;
     }
   }
-  //
+
   BitVector Available = rs.getRegsAvailable(&Mips::CPU16RegsRegClass);
-
   Available &= Candidates;
   //
   // we use T0 for the first register, if we need to save something away.
@@ -355,7 +369,6 @@
   unsigned FirstRegSaved =0, SecondRegSaved=0;
   unsigned FirstRegSavedTo = 0, SecondRegSavedTo = 0;
 
-
   Reg = Available.find_first();
 
   if (Reg == -1) {
@@ -393,7 +406,7 @@
     BuildMI(MBB, II, DL, get(Mips::  AdduRxRyRz16), Reg).addReg(FrameReg)
       .addReg(Reg, RegState::Kill);
   if (FirstRegSaved || SecondRegSaved) {
-    II = llvm::next(II);
+    II = std::next(II);
     if (FirstRegSaved)
       copyPhysReg(MBB, II, DL, FirstRegSaved, FirstRegSavedTo, true);
     if (SecondRegSaved)
@@ -423,7 +436,6 @@
   BuildMI(MBB, I, I->getDebugLoc(), get(Opc));
 }
 
-
 const MCInstrDesc &Mips16InstrInfo::AddiuSpImm(int64_t Imm) const {
   if (validSpImm8(Imm))
     return get(Mips::AddiuSpImm16);
@@ -437,8 +449,8 @@
   BuildMI(MBB, I, DL, AddiuSpImm(Imm)).addImm(Imm);
 }
 
-const MipsInstrInfo *llvm::createMips16InstrInfo(MipsTargetMachine &TM) {
-  return new Mips16InstrInfo(TM);
+const MipsInstrInfo *llvm::createMips16InstrInfo(const MipsSubtarget &STI) {
+  return new Mips16InstrInfo(STI);
 }
 
 bool Mips16InstrInfo::validImmediate(unsigned Opcode, unsigned Reg,
@@ -478,7 +490,6 @@
 unsigned Mips16InstrInfo::getInlineAsmLength(const char *Str,
                                              const MCAsmInfo &MAI) const {
 
-
   // Count the number of instructions in the asm.
   bool atInsnStart = true;
   unsigned Length = 0;