| //===-- PPCRegisterInfo.cpp - PowerPC Register Information ----------------===// |
| // |
| // 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 PowerPC implementation of the TargetRegisterInfo |
| // class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #define DEBUG_TYPE "reginfo" |
| #include "PPCRegisterInfo.h" |
| #include "PPC.h" |
| #include "PPCFrameLowering.h" |
| #include "PPCInstrBuilder.h" |
| #include "PPCMachineFunctionInfo.h" |
| #include "PPCSubtarget.h" |
| #include "llvm/ADT/BitVector.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/CallingConv.h" |
| #include "llvm/CodeGen/MachineFrameInfo.h" |
| #include "llvm/CodeGen/MachineFunction.h" |
| #include "llvm/CodeGen/MachineInstrBuilder.h" |
| #include "llvm/CodeGen/MachineModuleInfo.h" |
| #include "llvm/CodeGen/MachineRegisterInfo.h" |
| #include "llvm/CodeGen/RegisterScavenging.h" |
| #include "llvm/CodeGen/ValueTypes.h" |
| #include "llvm/Constants.h" |
| #include "llvm/Function.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/MathExtras.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Target/TargetFrameLowering.h" |
| #include "llvm/Target/TargetInstrInfo.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetOptions.h" |
| #include "llvm/Type.h" |
| #include <cstdlib> |
| |
| #define GET_REGINFO_TARGET_DESC |
| #include "PPCGenRegisterInfo.inc" |
| |
| namespace llvm { |
| cl::opt<bool> DisablePPC32RS("disable-ppc32-regscavenger", |
| cl::init(false), |
| cl::desc("Disable PPC32 register scavenger"), |
| cl::Hidden); |
| cl::opt<bool> DisablePPC64RS("disable-ppc64-regscavenger", |
| cl::init(false), |
| cl::desc("Disable PPC64 register scavenger"), |
| cl::Hidden); |
| } |
| |
| using namespace llvm; |
| |
| // FIXME (64-bit): Should be inlined. |
| bool |
| PPCRegisterInfo::requiresRegisterScavenging(const MachineFunction &) const { |
| return ((!DisablePPC32RS && !Subtarget.isPPC64()) || |
| (!DisablePPC64RS && Subtarget.isPPC64())); |
| } |
| |
| PPCRegisterInfo::PPCRegisterInfo(const PPCSubtarget &ST, |
| const TargetInstrInfo &tii) |
| : PPCGenRegisterInfo(ST.isPPC64() ? PPC::LR8 : PPC::LR, |
| ST.isPPC64() ? 0 : 1, |
| ST.isPPC64() ? 0 : 1), |
| Subtarget(ST), TII(tii), CRSpillFrameIdx(0) { |
| 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; |
| |
| // 64-bit |
| ImmToIdxMap[PPC::LHA8] = PPC::LHAX8; ImmToIdxMap[PPC::LBZ8] = PPC::LBZX8; |
| ImmToIdxMap[PPC::LHZ8] = PPC::LHZX8; ImmToIdxMap[PPC::LWZ8] = PPC::LWZX8; |
| ImmToIdxMap[PPC::STB8] = PPC::STBX8; ImmToIdxMap[PPC::STH8] = PPC::STHX8; |
| ImmToIdxMap[PPC::STW8] = PPC::STWX8; ImmToIdxMap[PPC::STDU] = PPC::STDUX; |
| ImmToIdxMap[PPC::ADDI8] = PPC::ADD8; ImmToIdxMap[PPC::STD_32] = PPC::STDX_32; |
| } |
| |
| bool |
| PPCRegisterInfo::trackLivenessAfterRegAlloc(const MachineFunction &MF) const { |
| return requiresRegisterScavenging(MF); |
| } |
| |
| |
| /// getPointerRegClass - Return the register class to use to hold pointers. |
| /// This is used for addressing modes. |
| const TargetRegisterClass * |
| PPCRegisterInfo::getPointerRegClass(const MachineFunction &MF, unsigned Kind) |
| const { |
| if (Subtarget.isPPC64()) |
| return &PPC::G8RCRegClass; |
| return &PPC::GPRCRegClass; |
| } |
| |
| const uint16_t* |
| PPCRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const { |
| if (Subtarget.isDarwinABI()) |
| return Subtarget.isPPC64() ? CSR_Darwin64_SaveList : |
| CSR_Darwin32_SaveList; |
| |
| // For 32-bit SVR4, also initialize the frame index associated with |
| // the CR spill slot. |
| if (!Subtarget.isPPC64()) |
| CRSpillFrameIdx = 0; |
| |
| return Subtarget.isPPC64() ? CSR_SVR464_SaveList : CSR_SVR432_SaveList; |
| } |
| |
| const uint32_t* |
| PPCRegisterInfo::getCallPreservedMask(CallingConv::ID CC) const { |
| if (Subtarget.isDarwinABI()) |
| return Subtarget.isPPC64() ? CSR_Darwin64_RegMask : |
| CSR_Darwin32_RegMask; |
| |
| return Subtarget.isPPC64() ? CSR_SVR464_RegMask : CSR_SVR432_RegMask; |
| } |
| |
| BitVector PPCRegisterInfo::getReservedRegs(const MachineFunction &MF) const { |
| BitVector Reserved(getNumRegs()); |
| const PPCFrameLowering *PPCFI = |
| static_cast<const PPCFrameLowering*>(MF.getTarget().getFrameLowering()); |
| |
| Reserved.set(PPC::R0); |
| Reserved.set(PPC::R1); |
| Reserved.set(PPC::LR); |
| Reserved.set(PPC::LR8); |
| Reserved.set(PPC::RM); |
| |
| // The SVR4 ABI reserves r2 and r13 |
| if (Subtarget.isSVR4ABI()) { |
| Reserved.set(PPC::R2); // System-reserved register |
| Reserved.set(PPC::R13); // Small Data Area pointer register |
| } |
| // Reserve R2 on Darwin to hack around the problem of save/restore of CR |
| // when the stack frame is too big to address directly; we need two regs. |
| // This is a hack. |
| if (Subtarget.isDarwinABI()) { |
| Reserved.set(PPC::R2); |
| } |
| |
| // On PPC64, r13 is the thread pointer. Never allocate this register. |
| // Note that this is over conservative, as it also prevents allocation of R31 |
| // when the FP is not needed. |
| if (Subtarget.isPPC64()) { |
| Reserved.set(PPC::R13); |
| Reserved.set(PPC::R31); |
| |
| Reserved.set(PPC::X0); |
| Reserved.set(PPC::X1); |
| Reserved.set(PPC::X13); |
| Reserved.set(PPC::X31); |
| |
| // The 64-bit SVR4 ABI reserves r2 for the TOC pointer. |
| if (Subtarget.isSVR4ABI()) { |
| Reserved.set(PPC::X2); |
| } |
| // Reserve X2 on Darwin to hack around the problem of save/restore of CR |
| // when the stack frame is too big to address directly; we need two regs. |
| // This is a hack. |
| if (Subtarget.isDarwinABI()) { |
| Reserved.set(PPC::X2); |
| } |
| } |
| |
| if (PPCFI->needsFP(MF)) |
| Reserved.set(PPC::R31); |
| |
| return Reserved; |
| } |
| |
| unsigned |
| PPCRegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC, |
| MachineFunction &MF) const { |
| const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering(); |
| const unsigned DefaultSafety = 1; |
| |
| switch (RC->getID()) { |
| default: |
| return 0; |
| case PPC::G8RCRegClassID: |
| case PPC::GPRCRegClassID: { |
| unsigned FP = TFI->hasFP(MF) ? 1 : 0; |
| return 32 - FP - DefaultSafety; |
| } |
| case PPC::F8RCRegClassID: |
| case PPC::F4RCRegClassID: |
| case PPC::VRRCRegClassID: |
| return 32 - DefaultSafety; |
| case PPC::CRRCRegClassID: |
| return 8 - DefaultSafety; |
| } |
| } |
| |
| bool |
| PPCRegisterInfo::avoidWriteAfterWrite(const TargetRegisterClass *RC) const { |
| switch (RC->getID()) { |
| case PPC::G8RCRegClassID: |
| case PPC::GPRCRegClassID: |
| case PPC::F8RCRegClassID: |
| case PPC::F4RCRegClassID: |
| case PPC::VRRCRegClassID: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Stack Frame Processing methods |
| //===----------------------------------------------------------------------===// |
| |
| void PPCRegisterInfo:: |
| eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator I) const { |
| if (MF.getTarget().Options.GuaranteedTailCallOpt && |
| I->getOpcode() == PPC::ADJCALLSTACKUP) { |
| // Add (actually subtract) back the amount the callee popped on return. |
| if (int CalleeAmt = I->getOperand(1).getImm()) { |
| bool is64Bit = Subtarget.isPPC64(); |
| CalleeAmt *= -1; |
| unsigned StackReg = is64Bit ? PPC::X1 : PPC::R1; |
| unsigned TmpReg = is64Bit ? PPC::X0 : PPC::R0; |
| unsigned ADDIInstr = is64Bit ? PPC::ADDI8 : PPC::ADDI; |
| unsigned ADDInstr = is64Bit ? PPC::ADD8 : PPC::ADD4; |
| unsigned LISInstr = is64Bit ? PPC::LIS8 : PPC::LIS; |
| unsigned ORIInstr = is64Bit ? PPC::ORI8 : PPC::ORI; |
| MachineInstr *MI = I; |
| DebugLoc dl = MI->getDebugLoc(); |
| |
| if (isInt<16>(CalleeAmt)) { |
| BuildMI(MBB, I, dl, TII.get(ADDIInstr), StackReg) |
| .addReg(StackReg, RegState::Kill) |
| .addImm(CalleeAmt); |
| } else { |
| MachineBasicBlock::iterator MBBI = I; |
| BuildMI(MBB, MBBI, dl, TII.get(LISInstr), TmpReg) |
| .addImm(CalleeAmt >> 16); |
| BuildMI(MBB, MBBI, dl, TII.get(ORIInstr), TmpReg) |
| .addReg(TmpReg, RegState::Kill) |
| .addImm(CalleeAmt & 0xFFFF); |
| BuildMI(MBB, MBBI, dl, TII.get(ADDInstr), StackReg) |
| .addReg(StackReg, RegState::Kill) |
| .addReg(TmpReg); |
| } |
| } |
| } |
| // Simply discard ADJCALLSTACKDOWN, ADJCALLSTACKUP instructions. |
| MBB.erase(I); |
| } |
| |
| /// findScratchRegister - Find a 'free' PPC register. Try for a call-clobbered |
| /// register first and then a spilled callee-saved register if that fails. |
| static |
| unsigned findScratchRegister(MachineBasicBlock::iterator II, RegScavenger *RS, |
| const TargetRegisterClass *RC, int SPAdj) { |
| assert(RS && "Register scavenging must be on"); |
| unsigned Reg = RS->FindUnusedReg(RC); |
| // FIXME: move ARM callee-saved reg scan to target independent code, then |
| // search for already spilled CS register here. |
| if (Reg == 0) |
| Reg = RS->scavengeRegister(RC, II, SPAdj); |
| return Reg; |
| } |
| |
| /// lowerDynamicAlloc - Generate the code for allocating an object in the |
| /// current frame. The sequence of code with be in the general form |
| /// |
| /// addi R0, SP, \#frameSize ; get the address of the previous frame |
| /// stwxu R0, SP, Rnegsize ; add and update the SP with the negated size |
| /// addi Rnew, SP, \#maxCalFrameSize ; get the top of the allocation |
| /// |
| void PPCRegisterInfo::lowerDynamicAlloc(MachineBasicBlock::iterator II, |
| int SPAdj, RegScavenger *RS) const { |
| // Get the instruction. |
| MachineInstr &MI = *II; |
| // Get the instruction's basic block. |
| MachineBasicBlock &MBB = *MI.getParent(); |
| // Get the basic block's function. |
| MachineFunction &MF = *MBB.getParent(); |
| // Get the frame info. |
| MachineFrameInfo *MFI = MF.getFrameInfo(); |
| // Determine whether 64-bit pointers are used. |
| bool LP64 = Subtarget.isPPC64(); |
| DebugLoc dl = MI.getDebugLoc(); |
| |
| // Get the maximum call stack size. |
| unsigned maxCallFrameSize = MFI->getMaxCallFrameSize(); |
| // Get the total frame size. |
| unsigned FrameSize = MFI->getStackSize(); |
| |
| // Get stack alignments. |
| unsigned TargetAlign = MF.getTarget().getFrameLowering()->getStackAlignment(); |
| unsigned MaxAlign = MFI->getMaxAlignment(); |
| if (MaxAlign > TargetAlign) |
| report_fatal_error("Dynamic alloca with large aligns not supported"); |
| |
| // Determine the previous frame's address. If FrameSize can't be |
| // represented as 16 bits or we need special alignment, then we load the |
| // previous frame's address from 0(SP). Why not do an addis of the hi? |
| // Because R0 is our only safe tmp register and addi/addis treat R0 as zero. |
| // Constructing the constant and adding would take 3 instructions. |
| // Fortunately, a frame greater than 32K is rare. |
| const TargetRegisterClass *G8RC = &PPC::G8RCRegClass; |
| const TargetRegisterClass *GPRC = &PPC::GPRCRegClass; |
| const TargetRegisterClass *RC = LP64 ? G8RC : GPRC; |
| |
| // FIXME (64-bit): Use "findScratchRegister" |
| unsigned Reg; |
| if (requiresRegisterScavenging(MF)) |
| Reg = findScratchRegister(II, RS, RC, SPAdj); |
| else |
| Reg = PPC::R0; |
| |
| if (MaxAlign < TargetAlign && isInt<16>(FrameSize)) { |
| BuildMI(MBB, II, dl, TII.get(PPC::ADDI), Reg) |
| .addReg(PPC::R31) |
| .addImm(FrameSize); |
| } else if (LP64) { |
| if (requiresRegisterScavenging(MF)) // FIXME (64-bit): Use "true" part. |
| BuildMI(MBB, II, dl, TII.get(PPC::LD), Reg) |
| .addImm(0) |
| .addReg(PPC::X1); |
| else |
| BuildMI(MBB, II, dl, TII.get(PPC::LD), PPC::X0) |
| .addImm(0) |
| .addReg(PPC::X1); |
| } else { |
| BuildMI(MBB, II, dl, TII.get(PPC::LWZ), Reg) |
| .addImm(0) |
| .addReg(PPC::R1); |
| } |
| |
| // Grow the stack and update the stack pointer link, then determine the |
| // address of new allocated space. |
| if (LP64) { |
| if (requiresRegisterScavenging(MF)) // FIXME (64-bit): Use "true" part. |
| BuildMI(MBB, II, dl, TII.get(PPC::STDUX), PPC::X1) |
| .addReg(Reg, RegState::Kill) |
| .addReg(PPC::X1) |
| .addReg(MI.getOperand(1).getReg()); |
| else |
| BuildMI(MBB, II, dl, TII.get(PPC::STDUX), PPC::X1) |
| .addReg(PPC::X0, RegState::Kill) |
| .addReg(PPC::X1) |
| .addReg(MI.getOperand(1).getReg()); |
| |
| if (!MI.getOperand(1).isKill()) |
| BuildMI(MBB, II, dl, TII.get(PPC::ADDI8), MI.getOperand(0).getReg()) |
| .addReg(PPC::X1) |
| .addImm(maxCallFrameSize); |
| else |
| // Implicitly kill the register. |
| BuildMI(MBB, II, dl, TII.get(PPC::ADDI8), MI.getOperand(0).getReg()) |
| .addReg(PPC::X1) |
| .addImm(maxCallFrameSize) |
| .addReg(MI.getOperand(1).getReg(), RegState::ImplicitKill); |
| } else { |
| BuildMI(MBB, II, dl, TII.get(PPC::STWUX), PPC::R1) |
| .addReg(Reg, RegState::Kill) |
| .addReg(PPC::R1) |
| .addReg(MI.getOperand(1).getReg()); |
| |
| if (!MI.getOperand(1).isKill()) |
| BuildMI(MBB, II, dl, TII.get(PPC::ADDI), MI.getOperand(0).getReg()) |
| .addReg(PPC::R1) |
| .addImm(maxCallFrameSize); |
| else |
| // Implicitly kill the register. |
| BuildMI(MBB, II, dl, TII.get(PPC::ADDI), MI.getOperand(0).getReg()) |
| .addReg(PPC::R1) |
| .addImm(maxCallFrameSize) |
| .addReg(MI.getOperand(1).getReg(), RegState::ImplicitKill); |
| } |
| |
| // Discard the DYNALLOC instruction. |
| MBB.erase(II); |
| } |
| |
| /// lowerCRSpilling - Generate the code for spilling a CR register. Instead of |
| /// reserving a whole register (R0), we scrounge for one here. This generates |
| /// code like this: |
| /// |
| /// mfcr rA ; Move the conditional register into GPR rA. |
| /// rlwinm rA, rA, SB, 0, 31 ; Shift the bits left so they are in CR0's slot. |
| /// stw rA, FI ; Store rA to the frame. |
| /// |
| void PPCRegisterInfo::lowerCRSpilling(MachineBasicBlock::iterator II, |
| unsigned FrameIndex, int SPAdj, |
| RegScavenger *RS) const { |
| // Get the instruction. |
| MachineInstr &MI = *II; // ; SPILL_CR <SrcReg>, <offset> |
| // Get the instruction's basic block. |
| MachineBasicBlock &MBB = *MI.getParent(); |
| DebugLoc dl = MI.getDebugLoc(); |
| |
| // FIXME: Once LLVM supports creating virtual registers here, or the register |
| // scavenger can return multiple registers, stop using reserved registers |
| // here. |
| (void) SPAdj; |
| (void) RS; |
| |
| bool LP64 = Subtarget.isPPC64(); |
| unsigned Reg = Subtarget.isDarwinABI() ? (LP64 ? PPC::X2 : PPC::R2) : |
| (LP64 ? PPC::X0 : PPC::R0); |
| unsigned SrcReg = MI.getOperand(0).getReg(); |
| |
| // We need to store the CR in the low 4-bits of the saved value. First, issue |
| // an MFCRpsued to save all of the CRBits and, if needed, kill the SrcReg. |
| BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFCR8pseud : PPC::MFCRpseud), Reg) |
| .addReg(SrcReg, getKillRegState(MI.getOperand(0).isKill())); |
| |
| // If the saved register wasn't CR0, shift the bits left so that they are in |
| // CR0's slot. |
| if (SrcReg != PPC::CR0) |
| // rlwinm rA, rA, ShiftBits, 0, 31. |
| BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg) |
| .addReg(Reg, RegState::Kill) |
| .addImm(getPPCRegisterNumbering(SrcReg) * 4) |
| .addImm(0) |
| .addImm(31); |
| |
| addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::STW8 : PPC::STW)) |
| .addReg(Reg, getKillRegState(MI.getOperand(1).getImm())), |
| FrameIndex); |
| |
| // Discard the pseudo instruction. |
| MBB.erase(II); |
| } |
| |
| void PPCRegisterInfo::lowerCRRestore(MachineBasicBlock::iterator II, |
| unsigned FrameIndex, int SPAdj, |
| RegScavenger *RS) const { |
| // Get the instruction. |
| MachineInstr &MI = *II; // ; <DestReg> = RESTORE_CR <offset> |
| // Get the instruction's basic block. |
| MachineBasicBlock &MBB = *MI.getParent(); |
| DebugLoc dl = MI.getDebugLoc(); |
| |
| // FIXME: Once LLVM supports creating virtual registers here, or the register |
| // scavenger can return multiple registers, stop using reserved registers |
| // here. |
| (void) SPAdj; |
| (void) RS; |
| |
| bool LP64 = Subtarget.isPPC64(); |
| unsigned Reg = Subtarget.isDarwinABI() ? (LP64 ? PPC::X2 : PPC::R2) : |
| (LP64 ? PPC::X0 : PPC::R0); |
| unsigned DestReg = MI.getOperand(0).getReg(); |
| assert(MI.definesRegister(DestReg) && |
| "RESTORE_CR does not define its destination"); |
| |
| addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LWZ8 : PPC::LWZ), |
| Reg), FrameIndex); |
| |
| // If the reloaded register isn't CR0, shift the bits right so that they are |
| // in the right CR's slot. |
| if (DestReg != PPC::CR0) { |
| unsigned ShiftBits = getPPCRegisterNumbering(DestReg)*4; |
| // rlwinm r11, r11, 32-ShiftBits, 0, 31. |
| BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg) |
| .addReg(Reg).addImm(32-ShiftBits).addImm(0) |
| .addImm(31); |
| } |
| |
| BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MTCRF8 : PPC::MTCRF), DestReg) |
| .addReg(Reg); |
| |
| // Discard the pseudo instruction. |
| MBB.erase(II); |
| } |
| |
| bool |
| PPCRegisterInfo::hasReservedSpillSlot(const MachineFunction &MF, |
| unsigned Reg, int &FrameIdx) const { |
| |
| // For the nonvolatile condition registers (CR2, CR3, CR4) in an SVR4 |
| // ABI, return true to prevent allocating an additional frame slot. |
| // For 64-bit, the CR save area is at SP+8; the value of FrameIdx = 0 |
| // is arbitrary and will be subsequently ignored. For 32-bit, we must |
| // create exactly one stack slot and return its FrameIdx for all |
| // nonvolatiles. |
| if (Subtarget.isSVR4ABI() && PPC::CR2 <= Reg && Reg <= PPC::CR4) { |
| if (Subtarget.isPPC64()) { |
| FrameIdx = 0; |
| } else if (CRSpillFrameIdx) { |
| FrameIdx = CRSpillFrameIdx; |
| } else { |
| MachineFrameInfo *MFI = |
| (const_cast<MachineFunction &>(MF)).getFrameInfo(); |
| FrameIdx = MFI->CreateFixedObject((uint64_t)4, (int64_t)-4, true); |
| CRSpillFrameIdx = FrameIdx; |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| void |
| PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, |
| int SPAdj, RegScavenger *RS) const { |
| assert(SPAdj == 0 && "Unexpected"); |
| |
| // Get the instruction. |
| MachineInstr &MI = *II; |
| // Get the instruction's basic block. |
| MachineBasicBlock &MBB = *MI.getParent(); |
| // Get the basic block's function. |
| MachineFunction &MF = *MBB.getParent(); |
| // Get the frame info. |
| MachineFrameInfo *MFI = MF.getFrameInfo(); |
| const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering(); |
| DebugLoc dl = MI.getDebugLoc(); |
| |
| // Find out which operand is the frame index. |
| unsigned FIOperandNo = 0; |
| while (!MI.getOperand(FIOperandNo).isFI()) { |
| ++FIOperandNo; |
| assert(FIOperandNo != MI.getNumOperands() && |
| "Instr doesn't have FrameIndex operand!"); |
| } |
| // Take into account whether it's an add or mem instruction |
| unsigned OffsetOperandNo = (FIOperandNo == 2) ? 1 : 2; |
| if (MI.isInlineAsm()) |
| OffsetOperandNo = FIOperandNo-1; |
| |
| // Get the frame index. |
| int FrameIndex = MI.getOperand(FIOperandNo).getIndex(); |
| |
| // Get the frame pointer save index. Users of this index are primarily |
| // DYNALLOC instructions. |
| PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>(); |
| int FPSI = FI->getFramePointerSaveIndex(); |
| // Get the instruction opcode. |
| unsigned OpC = MI.getOpcode(); |
| |
| // Special case for dynamic alloca. |
| if (FPSI && FrameIndex == FPSI && |
| (OpC == PPC::DYNALLOC || OpC == PPC::DYNALLOC8)) { |
| lowerDynamicAlloc(II, SPAdj, RS); |
| return; |
| } |
| |
| // Special case for pseudo-ops SPILL_CR and RESTORE_CR. |
| if (requiresRegisterScavenging(MF)) { |
| if (OpC == PPC::SPILL_CR) { |
| lowerCRSpilling(II, FrameIndex, SPAdj, RS); |
| return; |
| } else if (OpC == PPC::RESTORE_CR) { |
| lowerCRRestore(II, FrameIndex, SPAdj, RS); |
| return; |
| } |
| } |
| |
| // Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP). |
| |
| bool is64Bit = Subtarget.isPPC64(); |
| MI.getOperand(FIOperandNo).ChangeToRegister(TFI->hasFP(MF) ? |
| (is64Bit ? PPC::X31 : PPC::R31) : |
| (is64Bit ? PPC::X1 : PPC::R1), |
| false); |
| |
| // Figure out if the offset in the instruction is shifted right two bits. This |
| // is true for instructions like "STD", which the machine implicitly adds two |
| // low zeros to. |
| bool isIXAddr = false; |
| switch (OpC) { |
| case PPC::LWA: |
| case PPC::LD: |
| case PPC::STD: |
| case PPC::STD_32: |
| isIXAddr = true; |
| break; |
| } |
| |
| // Now add the frame object offset to the offset from r1. |
| int Offset = MFI->getObjectOffset(FrameIndex); |
| if (!isIXAddr) |
| Offset += MI.getOperand(OffsetOperandNo).getImm(); |
| else |
| Offset += MI.getOperand(OffsetOperandNo).getImm() << 2; |
| |
| // 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. |
| // Naked functions have stack size 0, although getStackSize may not reflect that |
| // because we didn't call all the pieces that compute it for naked functions. |
| if (!MF.getFunction()->getAttributes(). |
| hasAttribute(AttributeSet::FunctionIndex, Attribute::Naked)) |
| Offset += MFI->getStackSize(); |
| |
| // If we can, encode the offset directly into the instruction. If this is a |
| // normal PPC "ri" instruction, any 16-bit value can be safely encoded. If |
| // this is a PPC64 "ix" instruction, only a 16-bit value with the low two bits |
| // clear can be encoded. This is extremely uncommon, because normally you |
| // only "std" to a stack slot that is at least 4-byte aligned, but it can |
| // happen in invalid code. |
| if (OpC == PPC::DBG_VALUE || // DBG_VALUE is always Reg+Imm |
| (isInt<16>(Offset) && (!isIXAddr || (Offset & 3) == 0))) { |
| if (isIXAddr) |
| Offset >>= 2; // The actual encoded value has the low two bits zero. |
| MI.getOperand(OffsetOperandNo).ChangeToImmediate(Offset); |
| return; |
| } |
| |
| // The offset doesn't fit into a single register, scavenge one to build the |
| // offset in. |
| |
| unsigned SReg; |
| if (requiresRegisterScavenging(MF)) { |
| const TargetRegisterClass *G8RC = &PPC::G8RCRegClass; |
| const TargetRegisterClass *GPRC = &PPC::GPRCRegClass; |
| SReg = findScratchRegister(II, RS, is64Bit ? G8RC : GPRC, SPAdj); |
| } else |
| SReg = is64Bit ? PPC::X0 : PPC::R0; |
| |
| // Insert a set of rA with the full offset value before the ld, st, or add |
| BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::LIS8 : PPC::LIS), SReg) |
| .addImm(Offset >> 16); |
| BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::ORI8 : PPC::ORI), SReg) |
| .addReg(SReg, RegState::Kill) |
| .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 |
| unsigned OperandBase; |
| |
| if (OpC != TargetOpcode::INLINEASM) { |
| assert(ImmToIdxMap.count(OpC) && |
| "No indexed form of load or store available!"); |
| unsigned NewOpcode = ImmToIdxMap.find(OpC)->second; |
| MI.setDesc(TII.get(NewOpcode)); |
| OperandBase = 1; |
| } else { |
| OperandBase = OffsetOperandNo; |
| } |
| |
| unsigned StackReg = MI.getOperand(FIOperandNo).getReg(); |
| MI.getOperand(OperandBase).ChangeToRegister(StackReg, false); |
| MI.getOperand(OperandBase + 1).ChangeToRegister(SReg, false, false, true); |
| } |
| |
| unsigned PPCRegisterInfo::getFrameRegister(const MachineFunction &MF) const { |
| const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering(); |
| |
| if (!Subtarget.isPPC64()) |
| return TFI->hasFP(MF) ? PPC::R31 : PPC::R1; |
| else |
| return TFI->hasFP(MF) ? PPC::X31 : PPC::X1; |
| } |
| |
| unsigned PPCRegisterInfo::getEHExceptionRegister() const { |
| return !Subtarget.isPPC64() ? PPC::R3 : PPC::X3; |
| } |
| |
| unsigned PPCRegisterInfo::getEHHandlerRegister() const { |
| return !Subtarget.isPPC64() ? PPC::R4 : PPC::X4; |
| } |