1 files changed, 4 insertions, 175 deletions

diff --git a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
index 638e4e00d028..2f7cdfcf7bde 100644
--- a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
@@ -818,7 +818,7 @@ bool SystemZELFFrameLowering::usePackedStack(MachineFunction &MF) const {
 }
 
 SystemZXPLINKFrameLowering::SystemZXPLINKFrameLowering()
-    : SystemZFrameLowering(TargetFrameLowering::StackGrowsDown, Align(32), 0,
+    : SystemZFrameLowering(TargetFrameLowering::StackGrowsUp, Align(32), 128,
                            Align(32), /* StackRealignable */ false),
       RegSpillOffsets(-1) {
 
@@ -990,183 +990,12 @@ bool SystemZXPLINKFrameLowering::spillCalleeSavedRegisters(
   return true;
 }
 
-bool SystemZXPLINKFrameLowering::restoreCalleeSavedRegisters(
-    MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
-    MutableArrayRef<CalleeSavedInfo> CSI, const TargetRegisterInfo *TRI) const {
-
-  if (CSI.empty())
-    return false;
-
-  MachineFunction &MF = *MBB.getParent();
-  SystemZMachineFunctionInfo *ZFI = MF.getInfo<SystemZMachineFunctionInfo>();
-  const SystemZSubtarget &Subtarget = MF.getSubtarget<SystemZSubtarget>();
-  const TargetInstrInfo *TII = Subtarget.getInstrInfo();
-  auto &Regs = Subtarget.getSpecialRegisters<SystemZXPLINK64Registers>();
-
-  DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
-
-  // Restore FPRs in the normal TargetInstrInfo way.
-  for (unsigned I = 0, E = CSI.size(); I != E; ++I) {
-    unsigned Reg = CSI[I].getReg();
-    if (SystemZ::FP64BitRegClass.contains(Reg))
-      TII->loadRegFromStackSlot(MBB, MBBI, Reg, CSI[I].getFrameIdx(),
-                                &SystemZ::FP64BitRegClass, TRI);
-    if (SystemZ::VR128BitRegClass.contains(Reg))
-      TII->loadRegFromStackSlot(MBB, MBBI, Reg, CSI[I].getFrameIdx(),
-                                &SystemZ::VR128BitRegClass, TRI);
-  }
-
-  // Restore call-saved GPRs (but not call-clobbered varargs, which at
-  // this point might hold return values).
-  SystemZ::GPRRegs RestoreGPRs = ZFI->getRestoreGPRRegs();
-  if (RestoreGPRs.LowGPR) {
-    assert(isInt<20>(Regs.getStackPointerBias() + RestoreGPRs.GPROffset));
-    if (RestoreGPRs.LowGPR == RestoreGPRs.HighGPR)
-      // Build an LG/L instruction.
-      BuildMI(MBB, MBBI, DL, TII->get(SystemZ::LG), RestoreGPRs.LowGPR)
-          .addReg(Regs.getStackPointerRegister())
-          .addImm(Regs.getStackPointerBias() + RestoreGPRs.GPROffset)
-          .addReg(0);
-    else {
-      // Build an LMG/LM instruction.
-      MachineInstrBuilder MIB = BuildMI(MBB, MBBI, DL, TII->get(SystemZ::LMG));
-
-      // Add the explicit register operands.
-      MIB.addReg(RestoreGPRs.LowGPR, RegState::Define);
-      MIB.addReg(RestoreGPRs.HighGPR, RegState::Define);
-
-      // Add the address.
-      MIB.addReg(Regs.getStackPointerRegister());
-      MIB.addImm(Regs.getStackPointerBias() + RestoreGPRs.GPROffset);
-
-      // Do a second scan adding regs as being defined by instruction
-      for (unsigned I = 0, E = CSI.size(); I != E; ++I) {
-        unsigned Reg = CSI[I].getReg();
-        if (Reg > RestoreGPRs.LowGPR && Reg < RestoreGPRs.HighGPR)
-          MIB.addReg(Reg, RegState::ImplicitDefine);
-      }
-    }
-  }
-
-  return true;
-}
-
 void SystemZXPLINKFrameLowering::emitPrologue(MachineFunction &MF,
-                                              MachineBasicBlock &MBB) const {
-  assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
-  const SystemZSubtarget &Subtarget = MF.getSubtarget<SystemZSubtarget>();
-  SystemZMachineFunctionInfo *ZFI = MF.getInfo<SystemZMachineFunctionInfo>();
-  MachineBasicBlock::iterator MBBI = MBB.begin();
-  auto *ZII = static_cast<const SystemZInstrInfo *>(Subtarget.getInstrInfo());
-  auto &Regs = Subtarget.getSpecialRegisters<SystemZXPLINK64Registers>();
-  MachineFrameInfo &MFFrame = MF.getFrameInfo();
-  MachineInstr *StoreInstr = nullptr;
-  bool HasFP = hasFP(MF);
-  // Debug location must be unknown since the first debug location is used
-  // to determine the end of the prologue.
-  DebugLoc DL;
-  uint64_t Offset = 0;
-
-  // TODO: Support leaf functions; only add size of save+reserved area when
-  // function is non-leaf.
-  MFFrame.setStackSize(MFFrame.getStackSize() + Regs.getCallFrameSize());
-  uint64_t StackSize = MFFrame.getStackSize();
-
-  // FIXME: Implement support for large stack sizes, when the stack extension
-  // routine needs to be called.
-  if (StackSize > 1024 * 1024) {
-    llvm_unreachable("Huge Stack Frame not yet supported on z/OS");
-  }
-
-  if (ZFI->getSpillGPRRegs().LowGPR) {
-    // Skip over the GPR saves.
-    if ((MBBI != MBB.end()) && ((MBBI->getOpcode() == SystemZ::STMG))) {
-      const int Operand = 3;
-      // Now we can set the offset for the operation, since now the Stack
-      // has been finalized.
-      Offset = Regs.getStackPointerBias() + MBBI->getOperand(Operand).getImm();
-      // Maximum displacement for STMG instruction.
-      if (isInt<20>(Offset - StackSize))
-        Offset -= StackSize;
-      else
-        StoreInstr = &*MBBI;
-      MBBI->getOperand(Operand).setImm(Offset);
-      ++MBBI;
-    } else
-      llvm_unreachable("Couldn't skip over GPR saves");
-  }
-
-  if (StackSize) {
-    MachineBasicBlock::iterator InsertPt = StoreInstr ? StoreInstr : MBBI;
-    // Allocate StackSize bytes.
-    int64_t Delta = -int64_t(StackSize);
-
-    // In case the STM(G) instruction also stores SP (R4), but the displacement
-    // is too large, the SP register is manipulated first before storing,
-    // resulting in the wrong value stored and retrieved later. In this case, we
-    // need to temporarily save the value of SP, and store it later to memory.
-    if (StoreInstr && HasFP) {
-      // Insert LR r0,r4 before STMG instruction.
-      BuildMI(MBB, InsertPt, DL, ZII->get(SystemZ::LGR))
-          .addReg(SystemZ::R0D, RegState::Define)
-          .addReg(SystemZ::R4D);
-      // Insert ST r0,xxx(,r4) after STMG instruction.
-      BuildMI(MBB, MBBI, DL, ZII->get(SystemZ::STG), SystemZ::R0D)
-          .addReg(SystemZ::R4D)
-          .addImm(Offset)
-          .addReg(0);
-    }
-
-    emitIncrement(MBB, InsertPt, DL, Regs.getStackPointerRegister(), Delta,
-                  ZII);
-  }
-
-  if (HasFP) {
-    // Copy the base of the frame to Frame Pointer Register.
-    BuildMI(MBB, MBBI, DL, ZII->get(SystemZ::LGR),
-            Regs.getFramePointerRegister())
-        .addReg(Regs.getStackPointerRegister());
-
-    // Mark the FramePtr as live at the beginning of every block except
-    // the entry block.  (We'll have marked R8 as live on entry when
-    // saving the GPRs.)
-    for (auto I = std::next(MF.begin()), E = MF.end(); I != E; ++I)
-      I->addLiveIn(Regs.getFramePointerRegister());
-  }
-}
+                                              MachineBasicBlock &MBB) const {}
 
 void SystemZXPLINKFrameLowering::emitEpilogue(MachineFunction &MF,
-                                              MachineBasicBlock &MBB) const {
-  const SystemZSubtarget &Subtarget = MF.getSubtarget<SystemZSubtarget>();
-  MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
-  SystemZMachineFunctionInfo *ZFI = MF.getInfo<SystemZMachineFunctionInfo>();
-  MachineFrameInfo &MFFrame = MF.getFrameInfo();
-  auto *ZII = static_cast<const SystemZInstrInfo *>(Subtarget.getInstrInfo());
-  auto &Regs = Subtarget.getSpecialRegisters<SystemZXPLINK64Registers>();
-
-  // Skip the return instruction.
-  assert(MBBI->isReturn() && "Can only insert epilogue into returning blocks");
-
-  uint64_t StackSize = MFFrame.getStackSize();
-  if (StackSize) {
-    unsigned SPReg = Regs.getStackPointerRegister();
-    if (ZFI->getRestoreGPRRegs().LowGPR != SPReg) {
-      DebugLoc DL = MBBI->getDebugLoc();
-      emitIncrement(MBB, MBBI, DL, SPReg, StackSize, ZII);
-    }
-  }
-}
+                                              MachineBasicBlock &MBB) const {}
 
 bool SystemZXPLINKFrameLowering::hasFP(const MachineFunction &MF) const {
-  return (MF.getFrameInfo().hasVarSizedObjects());
-}
-
-void SystemZXPLINKFrameLowering::processFunctionBeforeFrameFinalized(
-    MachineFunction &MF, RegScavenger *RS) const {
-  MachineFrameInfo &MFFrame = MF.getFrameInfo();
-  const SystemZSubtarget &Subtarget = MF.getSubtarget<SystemZSubtarget>();
-  auto &Regs = Subtarget.getSpecialRegisters<SystemZXPLINK64Registers>();
-
-  // Setup stack frame offset
-  MFFrame.setOffsetAdjustment(Regs.getStackPointerBias());
+  return false;
 }