X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTarget%2FSystemZ%2FSystemZRegisterInfo.cpp;h=638fd17c9953ee05e32b791a9bb1482496bfed35;hb=6a45d681e53a99b4c4f63e0b1664626a596a8151;hp=ab92ebb89e827ce9b664484741d04c6ce269828a;hpb=17331245075fb99d1f79e2048e374ba16766a96c;p=oota-llvm.git

diff --git a/lib/Target/SystemZ/SystemZRegisterInfo.cpp b/lib/Target/SystemZ/SystemZRegisterInfo.cpp
index ab92ebb89e8..638fd17c995 100644
--- a/lib/Target/SystemZ/SystemZRegisterInfo.cpp
+++ b/lib/Target/SystemZ/SystemZRegisterInfo.cpp
@@ -77,7 +77,7 @@ BitVector SystemZRegisterInfo::getReservedRegs(const MachineFunction &MF) const
 /// allocas or if frame pointer elimination is disabled.
 bool SystemZRegisterInfo::hasFP(const MachineFunction &MF) const {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
-  return NoFramePointerElim || MFI->hasVarSizedObjects();
+  return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects();
 }
 
 void SystemZRegisterInfo::
@@ -86,10 +86,11 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
   MBB.erase(I);
 }
 
-int SystemZRegisterInfo::getFrameIndexOffset(MachineFunction &MF, int FI) const {
+int SystemZRegisterInfo::getFrameIndexOffset(const MachineFunction &MF,
+                                             int FI) const {
   const TargetFrameInfo &TFI = *MF.getTarget().getFrameInfo();
-  MachineFrameInfo *MFI = MF.getFrameInfo();
-  SystemZMachineFunctionInfo *SystemZMFI =
+  const MachineFrameInfo *MFI = MF.getFrameInfo();
+  const SystemZMachineFunctionInfo *SystemZMFI =
     MF.getInfo<SystemZMachineFunctionInfo>();
   int Offset = MFI->getObjectOffset(FI) + MFI->getOffsetAdjustment();
   uint64_t StackSize = MFI->getStackSize();
@@ -101,14 +102,16 @@ int SystemZRegisterInfo::getFrameIndexOffset(MachineFunction &MF, int FI) const
   Offset += StackSize - TFI.getOffsetOfLocalArea();
 
   // Skip the register save area if we generated the stack frame.
-  if (StackSize)
+  if (StackSize || MFI->hasCalls())
     Offset -= TFI.getOffsetOfLocalArea();
 
   return Offset;
 }
 
-void SystemZRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
-                                            int SPAdj, RegScavenger *RS) const {
+unsigned
+SystemZRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
+                                         int SPAdj, FrameIndexValue *Value,
+                                         RegScavenger *RS) const {
   assert(SPAdj == 0 && "Unxpected");
 
   unsigned i = 0;
@@ -133,10 +136,10 @@ void SystemZRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   int Offset = getFrameIndexOffset(MF, FrameIndex) + MI.getOperand(i+1).getImm();
 
   // Check whether displacement is too long to fit into 12 bit zext field.
-  if (Offset < 0 || Offset >= 4096)
-    MI.setDesc(TII.getLongDispOpc(MI.getOpcode()));
+  MI.setDesc(TII.getMemoryInstr(MI.getOpcode(), Offset));
 
   MI.getOperand(i+1).ChangeToImmediate(Offset);
+  return 0;
 }
 
 void
@@ -179,19 +182,25 @@ SystemZRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
 static
 void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
                   int64_t NumBytes, const TargetInstrInfo &TII) {
-  // FIXME: Handle different stack sizes here.
+  unsigned Opc; uint64_t Chunk;
   bool isSub = NumBytes < 0;
   uint64_t Offset = isSub ? -NumBytes : NumBytes;
-  unsigned Opc = SystemZ::ADD64ri16;
-  uint64_t Chunk = (1LL << 15) - 1;
-  DebugLoc DL = (MBBI != MBB.end() ? MBBI->getDebugLoc() :
-                 DebugLoc::getUnknownLoc());
+
+  if (Offset >= (1LL << 15) - 1) {
+    Opc = SystemZ::ADD64ri32;
+    Chunk = (1LL << 31) - 1;
+  } else {
+    Opc = SystemZ::ADD64ri16;
+    Chunk = (1LL << 15) - 1;
+  }
+
+  DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
 
   while (Offset) {
     uint64_t ThisVal = (Offset > Chunk) ? Chunk : Offset;
     MachineInstr *MI =
       BuildMI(MBB, MBBI, DL, TII.get(Opc), SystemZ::R15D)
-      .addReg(SystemZ::R15D).addImm((isSub ? -(int64_t)ThisVal : ThisVal));
+      .addReg(SystemZ::R15D).addImm(isSub ? -ThisVal : ThisVal);
     // The PSW implicit def is dead.
     MI->getOperand(3).setIsDead();
     Offset -= ThisVal;
@@ -205,8 +214,7 @@ void SystemZRegisterInfo::emitPrologue(MachineFunction &MF) const {
   SystemZMachineFunctionInfo *SystemZMFI =
     MF.getInfo<SystemZMachineFunctionInfo>();
   MachineBasicBlock::iterator MBBI = MBB.begin();
-  DebugLoc DL = (MBBI != MBB.end() ? MBBI->getDebugLoc() :
-                 DebugLoc::getUnknownLoc());
+  DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
 
   // Get the number of bytes to allocate from the FrameInfo.
   // Note that area for callee-saved stuff is already allocated, thus we need to
@@ -238,7 +246,7 @@ void SystemZRegisterInfo::emitPrologue(MachineFunction &MF) const {
       .addReg(SystemZ::R15D);
 
     // Mark the FramePtr as live-in in every block except the entry.
-    for (MachineFunction::iterator I = next(MF.begin()), E = MF.end();
+    for (MachineFunction::iterator I = llvm::next(MF.begin()), E = MF.end();
          I != E; ++I)
       I->addLiveIn(SystemZ::R11D);
 
@@ -253,7 +261,6 @@ void SystemZRegisterInfo::emitEpilogue(MachineFunction &MF,
   SystemZMachineFunctionInfo *SystemZMFI =
     MF.getInfo<SystemZMachineFunctionInfo>();
   unsigned RetOpcode = MBBI->getOpcode();
-  DebugLoc DL = MBBI->getDebugLoc();
 
   switch (RetOpcode) {
   case SystemZ::RET: break;  // These are ok
@@ -293,7 +300,17 @@ void SystemZRegisterInfo::emitEpilogue(MachineFunction &MF,
       assert(i < MI.getNumOperands() && "Unexpected restore code!");
     }
 
-    MI.getOperand(i).ChangeToImmediate(NumBytes + MI.getOperand(i).getImm());
+    uint64_t Offset = NumBytes + MI.getOperand(i).getImm();
+    // If Offset does not fit into 20-bit signed displacement field we need to
+    // emit some additional code...
+    if (Offset > 524287) {
+      // Fold the displacement into load instruction as much as possible.
+      NumBytes = Offset - 524287;
+      Offset = 524287;
+      emitSPUpdate(MBB, MBBI, NumBytes, TII);
+    }
+
+    MI.getOperand(i).ChangeToImmediate(Offset);
   }
 }
 
@@ -302,7 +319,8 @@ unsigned SystemZRegisterInfo::getRARegister() const {
   return 0;
 }
 
-unsigned SystemZRegisterInfo::getFrameRegister(MachineFunction &MF) const {
+unsigned
+SystemZRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
   assert(0 && "What is the frame register");
   return 0;
 }