| //===- PPCRegisterInfo.cpp - PowerPC Register Information -------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by the LLVM research group and is distributed under |
| // the University of Illinois Open Source License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file contains the PowerPC implementation of the MRegisterInfo class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #define DEBUG_TYPE "reginfo" |
| #include "PPC.h" |
| #include "PPCInstrBuilder.h" |
| #include "PPCRegisterInfo.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/Target/TargetFrameInfo.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetOptions.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/MathExtras.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include <cstdlib> |
| #include <iostream> |
| using namespace llvm; |
| |
| PPCRegisterInfo::PPCRegisterInfo() |
| : PPCGenRegisterInfo(PPC::ADJCALLSTACKDOWN, PPC::ADJCALLSTACKUP) { |
| ImmToIdxMap[PPC::LD] = PPC::LDX; ImmToIdxMap[PPC::STD] = PPC::STDX; |
| ImmToIdxMap[PPC::LBZ] = PPC::LBZX; ImmToIdxMap[PPC::STB] = PPC::STBX; |
| ImmToIdxMap[PPC::LHZ] = PPC::LHZX; ImmToIdxMap[PPC::LHA] = PPC::LHAX; |
| ImmToIdxMap[PPC::LWZ] = PPC::LWZX; ImmToIdxMap[PPC::LWA] = PPC::LWAX; |
| ImmToIdxMap[PPC::LFS] = PPC::LFSX; ImmToIdxMap[PPC::LFD] = PPC::LFDX; |
| ImmToIdxMap[PPC::STH] = PPC::STHX; ImmToIdxMap[PPC::STW] = PPC::STWX; |
| ImmToIdxMap[PPC::STFS] = PPC::STFSX; ImmToIdxMap[PPC::STFD] = PPC::STFDX; |
| ImmToIdxMap[PPC::ADDI] = PPC::ADD4; |
| } |
| |
| void |
| PPCRegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MI, |
| unsigned SrcReg, int FrameIdx, |
| const TargetRegisterClass *RC) const { |
| if (SrcReg == PPC::LR) { |
| BuildMI(MBB, MI, PPC::MFLR, 1, PPC::R11); |
| addFrameReference(BuildMI(MBB, MI, PPC::STW, 3).addReg(PPC::R11), FrameIdx); |
| } else if (RC == PPC::CRRCRegisterClass) { |
| BuildMI(MBB, MI, PPC::MFCR, 0, PPC::R11); |
| addFrameReference(BuildMI(MBB, MI, PPC::STW, 3).addReg(PPC::R11), FrameIdx); |
| } else if (RC == PPC::GPRCRegisterClass) { |
| addFrameReference(BuildMI(MBB, MI, PPC::STW, 3).addReg(SrcReg),FrameIdx); |
| } else if (RC == PPC::G8RCRegisterClass) { |
| addFrameReference(BuildMI(MBB, MI, PPC::STD, 3).addReg(SrcReg),FrameIdx); |
| } else if (RC == PPC::F8RCRegisterClass) { |
| addFrameReference(BuildMI(MBB, MI, PPC::STFD, 3).addReg(SrcReg),FrameIdx); |
| } else if (RC == PPC::F4RCRegisterClass) { |
| addFrameReference(BuildMI(MBB, MI, PPC::STFS, 3).addReg(SrcReg),FrameIdx); |
| } else { |
| assert(0 && "Unknown regclass!"); |
| abort(); |
| } |
| } |
| |
| void |
| PPCRegisterInfo::loadRegFromStackSlot(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MI, |
| unsigned DestReg, int FrameIdx, |
| const TargetRegisterClass *RC) const { |
| if (DestReg == PPC::LR) { |
| addFrameReference(BuildMI(MBB, MI, PPC::LWZ, 2, PPC::R11), FrameIdx); |
| BuildMI(MBB, MI, PPC::MTLR, 1).addReg(PPC::R11); |
| } else if (RC == PPC::CRRCRegisterClass) { |
| addFrameReference(BuildMI(MBB, MI, PPC::LWZ, 2, PPC::R11), FrameIdx); |
| BuildMI(MBB, MI, PPC::MTCRF, 1, DestReg).addReg(PPC::R11); |
| } else if (RC == PPC::GPRCRegisterClass) { |
| addFrameReference(BuildMI(MBB, MI, PPC::LWZ, 2, DestReg), FrameIdx); |
| } else if (RC == PPC::G8RCRegisterClass) { |
| addFrameReference(BuildMI(MBB, MI, PPC::LD, 2, DestReg), FrameIdx); |
| } else if (RC == PPC::F8RCRegisterClass) { |
| addFrameReference(BuildMI(MBB, MI, PPC::LFD, 2, DestReg), FrameIdx); |
| } else if (RC == PPC::F4RCRegisterClass) { |
| addFrameReference(BuildMI(MBB, MI, PPC::LFS, 2, DestReg), FrameIdx); |
| } else { |
| assert(0 && "Unknown regclass!"); |
| abort(); |
| } |
| } |
| |
| void PPCRegisterInfo::copyRegToReg(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MI, |
| unsigned DestReg, unsigned SrcReg, |
| const TargetRegisterClass *RC) const { |
| MachineInstr *I; |
| |
| if (RC == PPC::GPRCRegisterClass) { |
| BuildMI(MBB, MI, PPC::OR4, 2, DestReg).addReg(SrcReg).addReg(SrcReg); |
| } else if (RC == PPC::G8RCRegisterClass) { |
| BuildMI(MBB, MI, PPC::OR8, 2, DestReg).addReg(SrcReg).addReg(SrcReg); |
| } else if (RC == PPC::F4RCRegisterClass) { |
| BuildMI(MBB, MI, PPC::FMRS, 1, DestReg).addReg(SrcReg); |
| } else if (RC == PPC::F8RCRegisterClass) { |
| BuildMI(MBB, MI, PPC::FMRD, 1, DestReg).addReg(SrcReg); |
| } else if (RC == PPC::CRRCRegisterClass) { |
| BuildMI(MBB, MI, PPC::MCRF, 1, DestReg).addReg(SrcReg); |
| } else { |
| std::cerr << "Attempt to copy register that is not GPR or FPR"; |
| abort(); |
| } |
| } |
| |
| unsigned PPCRegisterInfo::isLoadFromStackSlot(MachineInstr *MI, |
| int &FrameIndex) const { |
| switch (MI->getOpcode()) { |
| default: break; |
| case PPC::LD: |
| case PPC::LWZ: |
| case PPC::LFS: |
| case PPC::LFD: |
| if (MI->getOperand(1).isImmediate() && !MI->getOperand(1).getImmedValue() && |
| MI->getOperand(2).isFrameIndex()) { |
| FrameIndex = MI->getOperand(2).getFrameIndex(); |
| return MI->getOperand(0).getReg(); |
| } |
| break; |
| } |
| return 0; |
| } |
| |
| /// foldMemoryOperand - PowerPC (like most RISC's) can only fold spills into |
| /// copy instructions, turning them into load/store instructions. |
| MachineInstr *PPCRegisterInfo::foldMemoryOperand(MachineInstr *MI, |
| unsigned OpNum, |
| int FrameIndex) const { |
| // Make sure this is a reg-reg copy. Note that we can't handle MCRF, because |
| // it takes more than one instruction to store it. |
| unsigned Opc = MI->getOpcode(); |
| |
| if ((Opc == PPC::OR4 && |
| MI->getOperand(1).getReg() == MI->getOperand(2).getReg())) { |
| if (OpNum == 0) { // move -> store |
| unsigned InReg = MI->getOperand(1).getReg(); |
| return addFrameReference(BuildMI(PPC::STW, |
| 3).addReg(InReg), FrameIndex); |
| } else { // move -> load |
| unsigned OutReg = MI->getOperand(0).getReg(); |
| return addFrameReference(BuildMI(PPC::LWZ, 2, OutReg), FrameIndex); |
| } |
| } else if ((Opc == PPC::OR8 && |
| MI->getOperand(1).getReg() == MI->getOperand(2).getReg())) { |
| if (OpNum == 0) { // move -> store |
| unsigned InReg = MI->getOperand(1).getReg(); |
| return addFrameReference(BuildMI(PPC::STD, |
| 3).addReg(InReg), FrameIndex); |
| } else { // move -> load |
| unsigned OutReg = MI->getOperand(0).getReg(); |
| return addFrameReference(BuildMI(PPC::LD, 2, OutReg), FrameIndex); |
| } |
| } else if (Opc == PPC::FMRD) { |
| if (OpNum == 0) { // move -> store |
| unsigned InReg = MI->getOperand(1).getReg(); |
| return addFrameReference(BuildMI(PPC::STFD, |
| 3).addReg(InReg), FrameIndex); |
| } else { // move -> load |
| unsigned OutReg = MI->getOperand(0).getReg(); |
| return addFrameReference(BuildMI(PPC::LFD, 2, OutReg), FrameIndex); |
| } |
| } else if (Opc == PPC::FMRS) { |
| if (OpNum == 0) { // move -> store |
| unsigned InReg = MI->getOperand(1).getReg(); |
| return addFrameReference(BuildMI(PPC::STFS, |
| 3).addReg(InReg), FrameIndex); |
| } else { // move -> load |
| unsigned OutReg = MI->getOperand(0).getReg(); |
| return addFrameReference(BuildMI(PPC::LFS, 2, OutReg), FrameIndex); |
| } |
| } |
| return 0; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // 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. |
| // |
| static bool hasFP(MachineFunction &MF) { |
| return NoFramePointerElim || MF.getFrameInfo()->hasVarSizedObjects(); |
| } |
| |
| void PPCRegisterInfo:: |
| eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator I) const { |
| if (hasFP(MF)) { |
| // If we have a frame pointer, convert as follows: |
| // ADJCALLSTACKDOWN -> addi, r1, r1, -amount |
| // ADJCALLSTACKUP -> addi, r1, r1, amount |
| MachineInstr *Old = I; |
| unsigned Amount = Old->getOperand(0).getImmedValue(); |
| 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() == PPC::ADJCALLSTACKDOWN) { |
| BuildMI(MBB, I, PPC::ADDI, 2, PPC::R1).addReg(PPC::R1).addSImm(-Amount); |
| } else { |
| assert(Old->getOpcode() == PPC::ADJCALLSTACKUP); |
| BuildMI(MBB, I, PPC::ADDI, 2, PPC::R1).addReg(PPC::R1).addSImm(Amount); |
| } |
| } |
| } |
| MBB.erase(I); |
| } |
| |
| void |
| PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II) const { |
| unsigned i = 0; |
| MachineInstr &MI = *II; |
| MachineBasicBlock &MBB = *MI.getParent(); |
| MachineFunction &MF = *MBB.getParent(); |
| |
| while (!MI.getOperand(i).isFrameIndex()) { |
| ++i; |
| assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!"); |
| } |
| |
| int FrameIndex = MI.getOperand(i).getFrameIndex(); |
| |
| // Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP). |
| MI.SetMachineOperandReg(i, hasFP(MF) ? PPC::R31 : PPC::R1); |
| |
| // Take into account whether it's an add or mem instruction |
| unsigned OffIdx = (i == 2) ? 1 : 2; |
| |
| // Now add the frame object offset to the offset from r1. |
| int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) + |
| MI.getOperand(OffIdx).getImmedValue(); |
| |
| // 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(); |
| |
| if (Offset > 32767 || Offset < -32768) { |
| // Insert a set of r0 with the full offset value before the ld, st, or add |
| MachineBasicBlock *MBB = MI.getParent(); |
| BuildMI(*MBB, II, PPC::LIS, 1, PPC::R0).addSImm(Offset >> 16); |
| BuildMI(*MBB, II, PPC::ORI, 2, PPC::R0).addReg(PPC::R0).addImm(Offset); |
| |
| // convert into indexed form of the instruction |
| // sth 0:rA, 1:imm 2:(rB) ==> sthx 0:rA, 2:rB, 1:r0 |
| // addi 0:rA 1:rB, 2, imm ==> add 0:rA, 1:rB, 2:r0 |
| assert(ImmToIdxMap.count(MI.getOpcode()) && |
| "No indexed form of load or store available!"); |
| unsigned NewOpcode = ImmToIdxMap.find(MI.getOpcode())->second; |
| MI.setOpcode(NewOpcode); |
| MI.SetMachineOperandReg(1, MI.getOperand(i).getReg()); |
| MI.SetMachineOperandReg(2, PPC::R0); |
| } else { |
| switch (MI.getOpcode()) { |
| case PPC::LWA: |
| case PPC::LD: |
| case PPC::STD: |
| case PPC::STDU: |
| assert((Offset & 3) == 0 && "Invalid frame offset!"); |
| Offset >>= 2; // The actual encoded value has the low two bits zero. |
| break; |
| } |
| MI.SetMachineOperandConst(OffIdx, MachineOperand::MO_SignExtendedImmed, |
| Offset); |
| } |
| } |
| |
| |
| void PPCRegisterInfo::emitPrologue(MachineFunction &MF) const { |
| MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB |
| MachineBasicBlock::iterator MBBI = MBB.begin(); |
| MachineFrameInfo *MFI = MF.getFrameInfo(); |
| |
| // Get the number of bytes to allocate from the FrameInfo |
| unsigned NumBytes = MFI->getStackSize(); |
| |
| // Get the alignments provided by the target, and the maximum alignment |
| // (if any) of the fixed frame objects. |
| unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment(); |
| unsigned MaxAlign = MFI->getMaxAlignment(); |
| |
| // If we have calls, we cannot use the red zone to store callee save registers |
| // and we must set up a stack frame, so calculate the necessary size here. |
| if (MFI->hasCalls()) { |
| // We reserve argument space for call sites in the function immediately on |
| // entry to the current function. This eliminates the need for add/sub |
| // brackets around call sites. |
| NumBytes += MFI->getMaxCallFrameSize(); |
| } |
| |
| // If we are a leaf function, and use up to 224 bytes of stack space, |
| // and don't have a frame pointer, then we do not need to adjust the stack |
| // pointer (we fit in the Red Zone). |
| if ((NumBytes == 0) || (NumBytes <= 224 && !hasFP(MF) && !MFI->hasCalls() && |
| MaxAlign <= TargetAlign)) { |
| MFI->setStackSize(0); |
| return; |
| } |
| |
| // Add the size of R1 to NumBytes size for the store of R1 to the bottom |
| // of the stack and round the size to a multiple of the alignment. |
| unsigned Align = std::max(TargetAlign, MaxAlign); |
| unsigned GPRSize = 4; |
| unsigned Size = hasFP(MF) ? GPRSize + GPRSize : GPRSize; |
| 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: r1 -= numbytes. |
| if (NumBytes <= 32768) { |
| BuildMI(MBB, MBBI, PPC::STWU, 3) |
| .addReg(PPC::R1).addSImm(-NumBytes).addReg(PPC::R1); |
| } else { |
| int NegNumbytes = -NumBytes; |
| BuildMI(MBB, MBBI, PPC::LIS, 1, PPC::R0).addSImm(NegNumbytes >> 16); |
| BuildMI(MBB, MBBI, PPC::ORI, 2, PPC::R0) |
| .addReg(PPC::R0).addImm(NegNumbytes & 0xFFFF); |
| BuildMI(MBB, MBBI, PPC::STWUX, 3) |
| .addReg(PPC::R1).addReg(PPC::R1).addReg(PPC::R0); |
| } |
| |
| // If there is a preferred stack alignment, align R1 now |
| // FIXME: If this ever matters, this could be made more efficient by folding |
| // this into the code above, so that we don't issue two store+update |
| // instructions. |
| if (MaxAlign > TargetAlign) { |
| assert(isPowerOf2_32(MaxAlign) && MaxAlign < 32767 && "Invalid alignment!"); |
| BuildMI(MBB, MBBI, PPC::RLWINM, 4, PPC::R0) |
| .addReg(PPC::R1).addImm(0).addImm(32-Log2_32(MaxAlign)).addImm(31); |
| BuildMI(MBB, MBBI, PPC::SUBFIC, 2,PPC::R0).addReg(PPC::R0).addImm(MaxAlign); |
| BuildMI(MBB, MBBI, PPC::STWUX, 3) |
| .addReg(PPC::R1).addReg(PPC::R1).addReg(PPC::R0); |
| } |
| |
| // If there is a frame pointer, copy R1 (SP) into R31 (FP) |
| if (hasFP(MF)) { |
| BuildMI(MBB, MBBI, PPC::STW, 3) |
| .addReg(PPC::R31).addSImm(GPRSize).addReg(PPC::R1); |
| BuildMI(MBB, MBBI, PPC::OR4, 2, PPC::R31).addReg(PPC::R1).addReg(PPC::R1); |
| } |
| } |
| |
| void PPCRegisterInfo::emitEpilogue(MachineFunction &MF, |
| MachineBasicBlock &MBB) const { |
| MachineBasicBlock::iterator MBBI = prior(MBB.end()); |
| assert(MBBI->getOpcode() == PPC::BLR && |
| "Can only insert epilog into returning blocks"); |
| |
| // Get the number of bytes allocated from the FrameInfo. |
| unsigned NumBytes = MF.getFrameInfo()->getStackSize(); |
| unsigned GPRSize = 4; |
| |
| if (NumBytes != 0) { |
| // If this function has a frame pointer, load the saved stack pointer from |
| // its stack slot. |
| if (hasFP(MF)) { |
| BuildMI(MBB, MBBI, PPC::LWZ, 2, PPC::R31) |
| .addSImm(GPRSize).addReg(PPC::R31); |
| } |
| |
| // The loaded (or persistent) stack pointer value is offseted by the 'stwu' |
| // on entry to the function. Add this offset back now. |
| if (NumBytes < 32768) { |
| BuildMI(MBB, MBBI, PPC::ADDI, 2, PPC::R1) |
| .addReg(PPC::R1).addSImm(NumBytes); |
| } else { |
| BuildMI(MBB, MBBI, PPC::LIS, 1, PPC::R0).addSImm(NumBytes >> 16); |
| BuildMI(MBB, MBBI, PPC::ORI, 2, PPC::R0) |
| .addReg(PPC::R0).addImm(NumBytes & 0xFFFF); |
| BuildMI(MBB, MBBI, PPC::ADD4, 2, PPC::R1) |
| .addReg(PPC::R0).addReg(PPC::R1); |
| } |
| } |
| } |
| |
| #include "PPCGenRegisterInfo.inc" |
| |