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Diffstat (limited to 'contrib/llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp')
| -rw-r--r-- | contrib/llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp | 645 |
1 files changed, 645 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp b/contrib/llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp new file mode 100644 index 0000000..2e90b7a --- /dev/null +++ b/contrib/llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp @@ -0,0 +1,645 @@ +//===- PPCRegisterInfo.cpp - PowerPC 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 PowerPC implementation of the TargetRegisterInfo +// class. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "reginfo" +#include "PPC.h" +#include "PPCInstrBuilder.h" +#include "PPCMachineFunctionInfo.h" +#include "PPCRegisterInfo.h" +#include "PPCFrameLowering.h" +#include "PPCSubtarget.h" +#include "llvm/CallingConv.h" +#include "llvm/Constants.h" +#include "llvm/Function.h" +#include "llvm/Type.h" +#include "llvm/CodeGen/ValueTypes.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" +#include "llvm/CodeGen/MachineModuleInfo.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/CodeGen/RegisterScavenging.h" +#include "llvm/Target/TargetFrameLowering.h" +#include "llvm/Target/TargetInstrInfo.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Target/TargetOptions.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/ADT/BitVector.h" +#include "llvm/ADT/STLExtras.h" +#include <cstdlib> + +#define GET_REGINFO_TARGET_DESC +#include "PPCGenRegisterInfo.inc" + +// FIXME (64-bit): Eventually enable by default. +namespace llvm { +cl::opt<bool> EnablePPC32RS("enable-ppc32-regscavenger", + cl::init(false), + cl::desc("Enable PPC32 register scavenger"), + cl::Hidden); +cl::opt<bool> EnablePPC64RS("enable-ppc64-regscavenger", + cl::init(false), + cl::desc("Enable PPC64 register scavenger"), + cl::Hidden); +} + +using namespace llvm; + +// FIXME (64-bit): Should be inlined. +bool +PPCRegisterInfo::requiresRegisterScavenging(const MachineFunction &) const { + return ((EnablePPC32RS && !Subtarget.isPPC64()) || + (EnablePPC64RS && 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) { + 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; +} + +/// getPointerRegClass - Return the register class to use to hold pointers. +/// This is used for addressing modes. +const TargetRegisterClass * +PPCRegisterInfo::getPointerRegClass(unsigned Kind) const { + if (Subtarget.isPPC64()) + return &PPC::G8RCRegClass; + return &PPC::GPRCRegClass; +} + +const unsigned* +PPCRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const { + // 32-bit Darwin calling convention. + static const unsigned Darwin32_CalleeSavedRegs[] = { + PPC::R13, PPC::R14, PPC::R15, + PPC::R16, PPC::R17, PPC::R18, PPC::R19, + PPC::R20, PPC::R21, PPC::R22, PPC::R23, + PPC::R24, PPC::R25, PPC::R26, PPC::R27, + PPC::R28, PPC::R29, PPC::R30, PPC::R31, + + PPC::F14, PPC::F15, PPC::F16, PPC::F17, + PPC::F18, PPC::F19, PPC::F20, PPC::F21, + PPC::F22, PPC::F23, PPC::F24, PPC::F25, + PPC::F26, PPC::F27, PPC::F28, PPC::F29, + PPC::F30, PPC::F31, + + PPC::CR2, PPC::CR3, PPC::CR4, + PPC::V20, PPC::V21, PPC::V22, PPC::V23, + PPC::V24, PPC::V25, PPC::V26, PPC::V27, + PPC::V28, PPC::V29, PPC::V30, PPC::V31, + + PPC::CR2LT, PPC::CR2GT, PPC::CR2EQ, PPC::CR2UN, + PPC::CR3LT, PPC::CR3GT, PPC::CR3EQ, PPC::CR3UN, + PPC::CR4LT, PPC::CR4GT, PPC::CR4EQ, PPC::CR4UN, + + PPC::LR, 0 + }; + + // 32-bit SVR4 calling convention. + static const unsigned SVR4_CalleeSavedRegs[] = { + PPC::R14, PPC::R15, + PPC::R16, PPC::R17, PPC::R18, PPC::R19, + PPC::R20, PPC::R21, PPC::R22, PPC::R23, + PPC::R24, PPC::R25, PPC::R26, PPC::R27, + PPC::R28, PPC::R29, PPC::R30, PPC::R31, + + PPC::F14, PPC::F15, PPC::F16, PPC::F17, + PPC::F18, PPC::F19, PPC::F20, PPC::F21, + PPC::F22, PPC::F23, PPC::F24, PPC::F25, + PPC::F26, PPC::F27, PPC::F28, PPC::F29, + PPC::F30, PPC::F31, + + PPC::CR2, PPC::CR3, PPC::CR4, + + PPC::VRSAVE, + + PPC::V20, PPC::V21, PPC::V22, PPC::V23, + PPC::V24, PPC::V25, PPC::V26, PPC::V27, + PPC::V28, PPC::V29, PPC::V30, PPC::V31, + + PPC::CR2LT, PPC::CR2GT, PPC::CR2EQ, PPC::CR2UN, + PPC::CR3LT, PPC::CR3GT, PPC::CR3EQ, PPC::CR3UN, + PPC::CR4LT, PPC::CR4GT, PPC::CR4EQ, PPC::CR4UN, + + 0 + }; + // 64-bit Darwin calling convention. + static const unsigned Darwin64_CalleeSavedRegs[] = { + PPC::X14, PPC::X15, + PPC::X16, PPC::X17, PPC::X18, PPC::X19, + PPC::X20, PPC::X21, PPC::X22, PPC::X23, + PPC::X24, PPC::X25, PPC::X26, PPC::X27, + PPC::X28, PPC::X29, PPC::X30, PPC::X31, + + PPC::F14, PPC::F15, PPC::F16, PPC::F17, + PPC::F18, PPC::F19, PPC::F20, PPC::F21, + PPC::F22, PPC::F23, PPC::F24, PPC::F25, + PPC::F26, PPC::F27, PPC::F28, PPC::F29, + PPC::F30, PPC::F31, + + PPC::CR2, PPC::CR3, PPC::CR4, + PPC::V20, PPC::V21, PPC::V22, PPC::V23, + PPC::V24, PPC::V25, PPC::V26, PPC::V27, + PPC::V28, PPC::V29, PPC::V30, PPC::V31, + + PPC::CR2LT, PPC::CR2GT, PPC::CR2EQ, PPC::CR2UN, + PPC::CR3LT, PPC::CR3GT, PPC::CR3EQ, PPC::CR3UN, + PPC::CR4LT, PPC::CR4GT, PPC::CR4EQ, PPC::CR4UN, + + PPC::LR8, 0 + }; + + // 64-bit SVR4 calling convention. + static const unsigned SVR4_64_CalleeSavedRegs[] = { + PPC::X14, PPC::X15, + PPC::X16, PPC::X17, PPC::X18, PPC::X19, + PPC::X20, PPC::X21, PPC::X22, PPC::X23, + PPC::X24, PPC::X25, PPC::X26, PPC::X27, + PPC::X28, PPC::X29, PPC::X30, PPC::X31, + + PPC::F14, PPC::F15, PPC::F16, PPC::F17, + PPC::F18, PPC::F19, PPC::F20, PPC::F21, + PPC::F22, PPC::F23, PPC::F24, PPC::F25, + PPC::F26, PPC::F27, PPC::F28, PPC::F29, + PPC::F30, PPC::F31, + + PPC::CR2, PPC::CR3, PPC::CR4, + + PPC::VRSAVE, + + PPC::V20, PPC::V21, PPC::V22, PPC::V23, + PPC::V24, PPC::V25, PPC::V26, PPC::V27, + PPC::V28, PPC::V29, PPC::V30, PPC::V31, + + PPC::CR2LT, PPC::CR2GT, PPC::CR2EQ, PPC::CR2UN, + PPC::CR3LT, PPC::CR3GT, PPC::CR3EQ, PPC::CR3UN, + PPC::CR4LT, PPC::CR4GT, PPC::CR4EQ, PPC::CR4UN, + + 0 + }; + + if (Subtarget.isDarwinABI()) + return Subtarget.isPPC64() ? Darwin64_CalleeSavedRegs : + Darwin32_CalleeSavedRegs; + + return Subtarget.isPPC64() ? SVR4_64_CalleeSavedRegs : SVR4_CalleeSavedRegs; +} + +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); + + if (!requiresRegisterScavenging(MF)) + Reserved.set(PPC::R0); // FIXME (64-bit): Remove + + 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 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::X2); + } + } + + if (PPCFI->needsFP(MF)) + Reserved.set(PPC::R31); + + return Reserved; +} + +//===----------------------------------------------------------------------===// +// Stack Frame Processing methods +//===----------------------------------------------------------------------===// + +void PPCRegisterInfo:: +eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, + MachineBasicBlock::iterator I) const { + if (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). + 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)) + .addReg(StackReg) + .addReg(StackReg) + .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)) + .addReg(Reg, RegState::Kill) + .addReg(PPC::X1) + .addReg(MI.getOperand(1).getReg()); + else + BuildMI(MBB, II, dl, TII.get(PPC::STDUX)) + .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)) + .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>, <FI> + // Get the instruction's basic block. + MachineBasicBlock &MBB = *MI.getParent(); + DebugLoc dl = MI.getDebugLoc(); + + const TargetRegisterClass *G8RC = &PPC::G8RCRegClass; + const TargetRegisterClass *GPRC = &PPC::GPRCRegClass; + const TargetRegisterClass *RC = Subtarget.isPPC64() ? G8RC : GPRC; + unsigned Reg = findScratchRegister(II, RS, RC, SPAdj); + unsigned SrcReg = MI.getOperand(0).getReg(); + bool LP64 = Subtarget.isPPC64(); + + // 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(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(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::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-op SPILL_CR. + if (requiresRegisterScavenging(MF)) // FIXME (64-bit): Enable by default. + if (OpC == PPC::SPILL_CR) { + lowerCRSpilling(II, FrameIndex, SPAdj, RS); + return; + } + + // Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP). + MI.getOperand(FIOperandNo).ChangeToRegister(TFI->hasFP(MF) ? + PPC::R31 : 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()->hasFnAttr(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 (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. + // FIXME: figure out what SPAdj is doing here. + + // FIXME (64-bit): Use "findScratchRegister". + unsigned SReg; + if (requiresRegisterScavenging(MF)) + SReg = findScratchRegister(II, RS, &PPC::GPRCRegClass, SPAdj); + else + SReg = PPC::R0; + + // Insert a set of rA with the full offset value before the ld, st, or add + BuildMI(MBB, II, dl, TII.get(PPC::LIS), SReg) + .addImm(Offset >> 16); + BuildMI(MBB, II, dl, TII.get(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); +} + +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; +} |
