| //===- IA64RegisterInfo.cpp - IA64 Register Information ---------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file contains the IA64 implementation of the TargetRegisterInfo class. |
| // This file is responsible for the frame pointer elimination optimization |
| // on IA64. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "IA64.h" |
| #include "IA64RegisterInfo.h" |
| #include "IA64InstrBuilder.h" |
| #include "IA64MachineFunctionInfo.h" |
| #include "llvm/Constants.h" |
| #include "llvm/Type.h" |
| #include "llvm/CodeGen/ValueTypes.h" |
| #include "llvm/CodeGen/MachineInstrBuilder.h" |
| #include "llvm/CodeGen/MachineFunction.h" |
| #include "llvm/CodeGen/MachineFrameInfo.h" |
| #include "llvm/CodeGen/MachineLocation.h" |
| #include "llvm/CodeGen/MachineRegisterInfo.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Target/TargetFrameInfo.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetOptions.h" |
| #include "llvm/Target/TargetInstrInfo.h" |
| #include "llvm/ADT/BitVector.h" |
| #include "llvm/ADT/STLExtras.h" |
| using namespace llvm; |
| |
| IA64RegisterInfo::IA64RegisterInfo(const TargetInstrInfo &tii) |
| : IA64GenRegisterInfo(IA64::ADJUSTCALLSTACKDOWN, IA64::ADJUSTCALLSTACKUP), |
| TII(tii) {} |
| |
| const unsigned* IA64RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) |
| const { |
| static const unsigned CalleeSavedRegs[] = { |
| IA64::r5, 0 |
| }; |
| return CalleeSavedRegs; |
| } |
| |
| const TargetRegisterClass* const* |
| IA64RegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const { |
| static const TargetRegisterClass * const CalleeSavedRegClasses[] = { |
| &IA64::GRRegClass, 0 |
| }; |
| return CalleeSavedRegClasses; |
| } |
| |
| BitVector IA64RegisterInfo::getReservedRegs(const MachineFunction &MF) const { |
| BitVector Reserved(getNumRegs()); |
| Reserved.set(IA64::r0); |
| Reserved.set(IA64::r1); |
| Reserved.set(IA64::r2); |
| Reserved.set(IA64::r5); |
| Reserved.set(IA64::r12); |
| Reserved.set(IA64::r13); |
| Reserved.set(IA64::r22); |
| Reserved.set(IA64::rp); |
| return Reserved; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Stack Frame Processing methods |
| //===----------------------------------------------------------------------===// |
| |
| // hasFP - Return true if the specified function should have a dedicated frame |
| // pointer register. This is true if the function has variable sized allocas or |
| // if frame pointer elimination is disabled. |
| // |
| bool IA64RegisterInfo::hasFP(const MachineFunction &MF) const { |
| const MachineFrameInfo *MFI = MF.getFrameInfo(); |
| return NoFramePointerElim || MFI->hasVarSizedObjects(); |
| } |
| |
| void IA64RegisterInfo:: |
| eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator I) const { |
| if (hasFP(MF)) { |
| // If we have a frame pointer, turn the adjcallstackup instruction into a |
| // 'sub SP, <amt>' and the adjcallstackdown instruction into 'add SP, |
| // <amt>' |
| MachineInstr *Old = I; |
| unsigned Amount = Old->getOperand(0).getImm(); |
| DebugLoc dl = Old->getDebugLoc(); |
| if (Amount != 0) { |
| // We need to keep the stack aligned properly. To do this, we round the |
| // amount of space needed for the outgoing arguments up to the next |
| // alignment boundary. |
| unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment(); |
| Amount = (Amount+Align-1)/Align*Align; |
| |
| // Replace the pseudo instruction with a new instruction... |
| if (Old->getOpcode() == IA64::ADJUSTCALLSTACKDOWN) { |
| BuildMI(MBB, I, dl, TII.get(IA64::ADDIMM22), IA64::r12) |
| .addReg(IA64::r12).addImm(-Amount); |
| } else { |
| assert(Old->getOpcode() == IA64::ADJUSTCALLSTACKUP); |
| BuildMI(MBB, I, dl, TII.get(IA64::ADDIMM22), IA64::r12) |
| .addReg(IA64::r12).addImm(Amount); |
| } |
| } |
| } |
| |
| MBB.erase(I); |
| } |
| |
| void IA64RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, |
| int SPAdj, RegScavenger *RS)const{ |
| assert(SPAdj == 0 && "Unexpected"); |
| |
| unsigned i = 0; |
| MachineInstr &MI = *II; |
| MachineBasicBlock &MBB = *MI.getParent(); |
| MachineFunction &MF = *MBB.getParent(); |
| DebugLoc dl = MI.getDebugLoc(); |
| |
| bool FP = hasFP(MF); |
| |
| while (!MI.getOperand(i).isFI()) { |
| ++i; |
| assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!"); |
| } |
| |
| int FrameIndex = MI.getOperand(i).getIndex(); |
| |
| // choose a base register: ( hasFP? framepointer : stack pointer ) |
| unsigned BaseRegister = FP ? IA64::r5 : IA64::r12; |
| // Add the base register |
| MI.getOperand(i).ChangeToRegister(BaseRegister, false); |
| |
| // Now add the frame object offset to the offset from r1. |
| int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex); |
| |
| // If we're not using a Frame Pointer that has been set to the value of the |
| // SP before having the stack size subtracted from it, then add the stack size |
| // to Offset to get the correct offset. |
| Offset += MF.getFrameInfo()->getStackSize(); |
| |
| // XXX: we use 'r22' as another hack+slash temporary register here :( |
| if (Offset <= 8191 && Offset >= -8192) { // smallish offset |
| // Fix up the old: |
| MI.getOperand(i).ChangeToRegister(IA64::r22, false); |
| //insert the new |
| BuildMI(MBB, II, dl, TII.get(IA64::ADDIMM22), IA64::r22) |
| .addReg(BaseRegister).addImm(Offset); |
| } else { // it's big |
| //fix up the old: |
| MI.getOperand(i).ChangeToRegister(IA64::r22, false); |
| BuildMI(MBB, II, dl, TII.get(IA64::MOVLIMM64), IA64::r22).addImm(Offset); |
| BuildMI(MBB, II, dl, TII.get(IA64::ADD), IA64::r22).addReg(BaseRegister) |
| .addReg(IA64::r22); |
| } |
| |
| } |
| |
| void IA64RegisterInfo::emitPrologue(MachineFunction &MF) const { |
| MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB |
| MachineBasicBlock::iterator MBBI = MBB.begin(); |
| MachineFrameInfo *MFI = MF.getFrameInfo(); |
| bool FP = hasFP(MF); |
| DebugLoc dl = (MBBI != MBB.end() ? |
| MBBI->getDebugLoc() : DebugLoc::getUnknownLoc()); |
| |
| // first, we handle the 'alloc' instruction, that should be right up the |
| // top of any function |
| static const unsigned RegsInOrder[96] = { // there are 96 GPRs the |
| // RSE worries about |
| IA64::r32, IA64::r33, IA64::r34, IA64::r35, |
| IA64::r36, IA64::r37, IA64::r38, IA64::r39, IA64::r40, IA64::r41, |
| IA64::r42, IA64::r43, IA64::r44, IA64::r45, IA64::r46, IA64::r47, |
| IA64::r48, IA64::r49, IA64::r50, IA64::r51, IA64::r52, IA64::r53, |
| IA64::r54, IA64::r55, IA64::r56, IA64::r57, IA64::r58, IA64::r59, |
| IA64::r60, IA64::r61, IA64::r62, IA64::r63, IA64::r64, IA64::r65, |
| IA64::r66, IA64::r67, IA64::r68, IA64::r69, IA64::r70, IA64::r71, |
| IA64::r72, IA64::r73, IA64::r74, IA64::r75, IA64::r76, IA64::r77, |
| IA64::r78, IA64::r79, IA64::r80, IA64::r81, IA64::r82, IA64::r83, |
| IA64::r84, IA64::r85, IA64::r86, IA64::r87, IA64::r88, IA64::r89, |
| IA64::r90, IA64::r91, IA64::r92, IA64::r93, IA64::r94, IA64::r95, |
| IA64::r96, IA64::r97, IA64::r98, IA64::r99, IA64::r100, IA64::r101, |
| IA64::r102, IA64::r103, IA64::r104, IA64::r105, IA64::r106, IA64::r107, |
| IA64::r108, IA64::r109, IA64::r110, IA64::r111, IA64::r112, IA64::r113, |
| IA64::r114, IA64::r115, IA64::r116, IA64::r117, IA64::r118, IA64::r119, |
| IA64::r120, IA64::r121, IA64::r122, IA64::r123, IA64::r124, IA64::r125, |
| IA64::r126, IA64::r127 }; |
| |
| unsigned numStackedGPRsUsed=0; |
| for (int i=0; i != 96; i++) { |
| if (MF.getRegInfo().isPhysRegUsed(RegsInOrder[i])) |
| numStackedGPRsUsed=i+1; // (i+1 and not ++ - consider fn(fp, fp, int) |
| } |
| |
| unsigned numOutRegsUsed=MF.getInfo<IA64FunctionInfo>()->outRegsUsed; |
| |
| // XXX FIXME : this code should be a bit more reliable (in case there _isn't_ |
| // a pseudo_alloc in the MBB) |
| unsigned dstRegOfPseudoAlloc; |
| for(MBBI = MBB.begin(); /*MBBI->getOpcode() != IA64::PSEUDO_ALLOC*/; ++MBBI) { |
| assert(MBBI != MBB.end()); |
| if(MBBI->getOpcode() == IA64::PSEUDO_ALLOC) { |
| dstRegOfPseudoAlloc=MBBI->getOperand(0).getReg(); |
| break; |
| } |
| } |
| |
| if (MBBI != MBB.end()) dl = MBBI->getDebugLoc(); |
| |
| BuildMI(MBB, MBBI, dl, TII.get(IA64::ALLOC)). |
| addReg(dstRegOfPseudoAlloc).addImm(0). |
| addImm(numStackedGPRsUsed).addImm(numOutRegsUsed).addImm(0); |
| |
| // Get the number of bytes to allocate from the FrameInfo |
| unsigned NumBytes = MFI->getStackSize(); |
| |
| if(FP) |
| NumBytes += 8; // reserve space for the old FP |
| |
| // Do we need to allocate space on the stack? |
| if (NumBytes == 0) |
| return; |
| |
| // Add 16 bytes at the bottom of the stack (scratch area) |
| // and round the size to a multiple of the alignment. |
| unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment(); |
| unsigned Size = 16 + (FP ? 8 : 0); |
| NumBytes = (NumBytes+Size+Align-1)/Align*Align; |
| |
| // Update frame info to pretend that this is part of the stack... |
| MFI->setStackSize(NumBytes); |
| |
| // adjust stack pointer: r12 -= numbytes |
| if (NumBytes <= 8191) { |
| BuildMI(MBB, MBBI, dl, TII.get(IA64::ADDIMM22),IA64::r12).addReg(IA64::r12). |
| addImm(-NumBytes); |
| } else { // we use r22 as a scratch register here |
| // first load the decrement into r22 |
| BuildMI(MBB, MBBI, dl, TII.get(IA64::MOVLIMM64), IA64::r22). |
| addImm(-NumBytes); |
| // FIXME: MOVLSI32 expects a _u_32imm |
| // then add (subtract) it to r12 (stack ptr) |
| BuildMI(MBB, MBBI, dl, TII.get(IA64::ADD), IA64::r12) |
| .addReg(IA64::r12).addReg(IA64::r22); |
| |
| } |
| |
| // now if we need to, save the old FP and set the new |
| if (FP) { |
| BuildMI(MBB, MBBI,dl,TII.get(IA64::ST8)).addReg(IA64::r12).addReg(IA64::r5); |
| // this must be the last instr in the prolog ? (XXX: why??) |
| BuildMI(MBB, MBBI, dl, TII.get(IA64::MOV), IA64::r5).addReg(IA64::r12); |
| } |
| |
| } |
| |
| void IA64RegisterInfo::emitEpilogue(MachineFunction &MF, |
| MachineBasicBlock &MBB) const { |
| const MachineFrameInfo *MFI = MF.getFrameInfo(); |
| MachineBasicBlock::iterator MBBI = prior(MBB.end()); |
| assert(MBBI->getOpcode() == IA64::RET && |
| "Can only insert epilog into returning blocks"); |
| DebugLoc dl = MBBI->getDebugLoc(); |
| bool FP = hasFP(MF); |
| |
| // Get the number of bytes allocated from the FrameInfo... |
| unsigned NumBytes = MFI->getStackSize(); |
| |
| //now if we need to, restore the old FP |
| if (FP) { |
| //copy the FP into the SP (discards allocas) |
| BuildMI(MBB, MBBI, dl, TII.get(IA64::MOV), IA64::r12).addReg(IA64::r5); |
| //restore the FP |
| BuildMI(MBB, MBBI, dl, TII.get(IA64::LD8), IA64::r5).addReg(IA64::r5); |
| } |
| |
| if (NumBytes != 0) { |
| if (NumBytes <= 8191) { |
| BuildMI(MBB, MBBI, dl, TII.get(IA64::ADDIMM22),IA64::r12). |
| addReg(IA64::r12).addImm(NumBytes); |
| } else { |
| BuildMI(MBB, MBBI, dl, TII.get(IA64::MOVLIMM64), IA64::r22). |
| addImm(NumBytes); |
| BuildMI(MBB, MBBI, dl, TII.get(IA64::ADD), IA64::r12).addReg(IA64::r12). |
| addReg(IA64::r22); |
| } |
| } |
| } |
| |
| unsigned IA64RegisterInfo::getRARegister() const { |
| llvm_unreachable("What is the return address register"); |
| return 0; |
| } |
| |
| unsigned IA64RegisterInfo::getFrameRegister(MachineFunction &MF) const { |
| return hasFP(MF) ? IA64::r5 : IA64::r12; |
| } |
| |
| unsigned IA64RegisterInfo::getEHExceptionRegister() const { |
| llvm_unreachable("What is the exception register"); |
| return 0; |
| } |
| |
| unsigned IA64RegisterInfo::getEHHandlerRegister() const { |
| llvm_unreachable("What is the exception handler register"); |
| return 0; |
| } |
| |
| int IA64RegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const { |
| llvm_unreachable("What is the dwarf register number"); |
| return -1; |
| } |
| |
| #include "IA64GenRegisterInfo.inc" |
| |