-//===- ARMRegisterInfo.cpp - ARM Register Information -----------*- C++ -*-===//
+//===-- ARMRegisterInfo.cpp - ARM Register Information --------------------===//
//
// The LLVM Compiler Infrastructure
//
//
//===----------------------------------------------------------------------===//
//
-// This file contains the ARM implementation of the MRegisterInfo class.
+// This file contains the ARM implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
-#include "ARM.h"
-#include "ARMAddressingModes.h"
-#include "ARMInstrInfo.h"
-#include "ARMMachineFunctionInfo.h"
#include "ARMRegisterInfo.h"
-#include "ARMSubtarget.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/CodeGen/MachineConstantPool.h"
-#include "llvm/CodeGen/MachineFrameInfo.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/MachineLocation.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/RegisterScavenging.h"
-#include "llvm/Target/TargetFrameInfo.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/TargetOptions.h"
-#include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/Support/CommandLine.h"
-#include <algorithm>
using namespace llvm;
-static cl::opt<bool> ThumbRegScavenging("enable-thumb-reg-scavenging",
- cl::Hidden,
- cl::desc("Enable register scavenging on Thumb"));
-
-unsigned ARMRegisterInfo::getRegisterNumbering(unsigned RegEnum) {
- using namespace ARM;
- switch (RegEnum) {
- case R0: case S0: case D0: return 0;
- case R1: case S1: case D1: return 1;
- case R2: case S2: case D2: return 2;
- case R3: case S3: case D3: return 3;
- case R4: case S4: case D4: return 4;
- case R5: case S5: case D5: return 5;
- case R6: case S6: case D6: return 6;
- case R7: case S7: case D7: return 7;
- case R8: case S8: case D8: return 8;
- case R9: case S9: case D9: return 9;
- case R10: case S10: case D10: return 10;
- case R11: case S11: case D11: return 11;
- case R12: case S12: case D12: return 12;
- case SP: case S13: case D13: return 13;
- case LR: case S14: case D14: return 14;
- case PC: case S15: case D15: return 15;
- case S16: return 16;
- case S17: return 17;
- case S18: return 18;
- case S19: return 19;
- case S20: return 20;
- case S21: return 21;
- case S22: return 22;
- case S23: return 23;
- case S24: return 24;
- case S25: return 25;
- case S26: return 26;
- case S27: return 27;
- case S28: return 28;
- case S29: return 29;
- case S30: return 30;
- case S31: return 31;
- default:
- assert(0 && "Unknown ARM register!");
- abort();
- }
-}
-
-ARMRegisterInfo::ARMRegisterInfo(const TargetInstrInfo &tii,
- const ARMSubtarget &sti)
- : ARMGenRegisterInfo(ARM::ADJCALLSTACKDOWN, ARM::ADJCALLSTACKUP),
- TII(tii), STI(sti),
- FramePtr((STI.useThumbBacktraces() || STI.isThumb()) ? ARM::R7 : ARM::R11) {
-}
-
-static inline
-const MachineInstrBuilder &AddDefaultPred(const MachineInstrBuilder &MIB) {
- return MIB.addImm((int64_t)ARMCC::AL).addReg(0);
-}
-
-static inline
-const MachineInstrBuilder &AddDefaultCC(const MachineInstrBuilder &MIB) {
- return MIB.addReg(0);
-}
-
-/// emitLoadConstPool - Emits a load from constpool to materialize the
-/// specified immediate.
-static void emitLoadConstPool(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- unsigned DestReg, int Val,
- ARMCC::CondCodes Pred, unsigned PredReg,
- const TargetInstrInfo &TII, bool isThumb) {
- MachineFunction &MF = *MBB.getParent();
- MachineConstantPool *ConstantPool = MF.getConstantPool();
- Constant *C = ConstantInt::get(Type::Int32Ty, Val);
- unsigned Idx = ConstantPool->getConstantPoolIndex(C, 2);
- if (isThumb)
- BuildMI(MBB, MBBI, TII.get(ARM::tLDRcp), DestReg).addConstantPoolIndex(Idx);
- else
- BuildMI(MBB, MBBI, TII.get(ARM::LDRcp), DestReg).addConstantPoolIndex(Idx)
- .addReg(0).addImm(0).addImm((unsigned)Pred).addReg(PredReg);
-}
-
-void ARMRegisterInfo::reMaterialize(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator I,
- unsigned DestReg,
- const MachineInstr *Orig) const {
- if (Orig->getOpcode() == ARM::MOVi2pieces) {
- emitLoadConstPool(MBB, I, DestReg,
- Orig->getOperand(1).getImm(),
- (ARMCC::CondCodes)Orig->getOperand(2).getImm(),
- Orig->getOperand(3).getReg(),
- TII, false);
- return;
- }
-
- MachineInstr *MI = Orig->clone();
- MI->getOperand(0).setReg(DestReg);
- MBB.insert(I, MI);
-}
-
-/// isLowRegister - Returns true if the register is low register r0-r7.
-///
-static bool isLowRegister(unsigned Reg) {
- using namespace ARM;
- switch (Reg) {
- case R0: case R1: case R2: case R3:
- case R4: case R5: case R6: case R7:
- return true;
- default:
- return false;
- }
-}
-
-MachineInstr *ARMRegisterInfo::foldMemoryOperand(MachineInstr *MI,
- SmallVectorImpl<unsigned> &Ops,
- int FI) const {
- if (Ops.size() != 1) return NULL;
-
- unsigned OpNum = Ops[0];
- unsigned Opc = MI->getOpcode();
- MachineInstr *NewMI = NULL;
- switch (Opc) {
- default: break;
- case ARM::MOVr: {
- if (MI->getOperand(4).getReg() == ARM::CPSR)
- // If it is updating CPSR, then it cannot be foled.
- break;
- unsigned Pred = MI->getOperand(2).getImm();
- unsigned PredReg = MI->getOperand(3).getReg();
- if (OpNum == 0) { // move -> store
- unsigned SrcReg = MI->getOperand(1).getReg();
- NewMI = BuildMI(TII.get(ARM::STR)).addReg(SrcReg).addFrameIndex(FI)
- .addReg(0).addImm(0).addImm(Pred).addReg(PredReg);
- } else { // move -> load
- unsigned DstReg = MI->getOperand(0).getReg();
- NewMI = BuildMI(TII.get(ARM::LDR), DstReg).addFrameIndex(FI).addReg(0)
- .addImm(0).addImm(Pred).addReg(PredReg);
- }
- break;
- }
- case ARM::tMOVr: {
- if (OpNum == 0) { // move -> store
- unsigned SrcReg = MI->getOperand(1).getReg();
- if (isPhysicalRegister(SrcReg) && !isLowRegister(SrcReg))
- // tSpill cannot take a high register operand.
- break;
- NewMI = BuildMI(TII.get(ARM::tSpill)).addReg(SrcReg).addFrameIndex(FI)
- .addImm(0);
- } else { // move -> load
- unsigned DstReg = MI->getOperand(0).getReg();
- if (isPhysicalRegister(DstReg) && !isLowRegister(DstReg))
- // tRestore cannot target a high register operand.
- break;
- NewMI = BuildMI(TII.get(ARM::tRestore), DstReg).addFrameIndex(FI)
- .addImm(0);
- }
- break;
- }
- case ARM::FCPYS: {
- unsigned Pred = MI->getOperand(2).getImm();
- unsigned PredReg = MI->getOperand(3).getReg();
- if (OpNum == 0) { // move -> store
- unsigned SrcReg = MI->getOperand(1).getReg();
- NewMI = BuildMI(TII.get(ARM::FSTS)).addReg(SrcReg).addFrameIndex(FI)
- .addImm(0).addImm(Pred).addReg(PredReg);
- } else { // move -> load
- unsigned DstReg = MI->getOperand(0).getReg();
- NewMI = BuildMI(TII.get(ARM::FLDS), DstReg).addFrameIndex(FI)
- .addImm(0).addImm(Pred).addReg(PredReg);
- }
- break;
- }
- case ARM::FCPYD: {
- unsigned Pred = MI->getOperand(2).getImm();
- unsigned PredReg = MI->getOperand(3).getReg();
- if (OpNum == 0) { // move -> store
- unsigned SrcReg = MI->getOperand(1).getReg();
- NewMI = BuildMI(TII.get(ARM::FSTD)).addReg(SrcReg).addFrameIndex(FI)
- .addImm(0).addImm(Pred).addReg(PredReg);
- } else { // move -> load
- unsigned DstReg = MI->getOperand(0).getReg();
- NewMI = BuildMI(TII.get(ARM::FLDD), DstReg).addFrameIndex(FI)
- .addImm(0).addImm(Pred).addReg(PredReg);
- }
- break;
- }
- }
-
- if (NewMI)
- NewMI->copyKillDeadInfo(MI);
- return NewMI;
-}
-
-bool ARMRegisterInfo::canFoldMemoryOperand(MachineInstr *MI,
- SmallVectorImpl<unsigned> &Ops) const {
- if (Ops.size() != 1) return false;
-
- unsigned OpNum = Ops[0];
- unsigned Opc = MI->getOpcode();
- switch (Opc) {
- default: break;
- case ARM::MOVr:
- // If it is updating CPSR, then it cannot be foled.
- return MI->getOperand(4).getReg() != ARM::CPSR;
- case ARM::tMOVr: {
- if (OpNum == 0) { // move -> store
- unsigned SrcReg = MI->getOperand(1).getReg();
- if (isPhysicalRegister(SrcReg) && !isLowRegister(SrcReg))
- // tSpill cannot take a high register operand.
- return false;
- } else { // move -> load
- unsigned DstReg = MI->getOperand(0).getReg();
- if (isPhysicalRegister(DstReg) && !isLowRegister(DstReg))
- // tRestore cannot target a high register operand.
- return false;
- }
- return true;
- }
- case ARM::FCPYS:
- case ARM::FCPYD:
- return true;
- }
-
- return false;
-}
-
-const unsigned*
-ARMRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
- static const unsigned CalleeSavedRegs[] = {
- ARM::LR, ARM::R11, ARM::R10, ARM::R9, ARM::R8,
- ARM::R7, ARM::R6, ARM::R5, ARM::R4,
-
- ARM::D15, ARM::D14, ARM::D13, ARM::D12,
- ARM::D11, ARM::D10, ARM::D9, ARM::D8,
- 0
- };
-
- static const unsigned DarwinCalleeSavedRegs[] = {
- ARM::LR, ARM::R7, ARM::R6, ARM::R5, ARM::R4,
- ARM::R11, ARM::R10, ARM::R9, ARM::R8,
-
- ARM::D15, ARM::D14, ARM::D13, ARM::D12,
- ARM::D11, ARM::D10, ARM::D9, ARM::D8,
- 0
- };
- return STI.isTargetDarwin() ? DarwinCalleeSavedRegs : CalleeSavedRegs;
-}
-
-const TargetRegisterClass* const *
-ARMRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
- static const TargetRegisterClass * const CalleeSavedRegClasses[] = {
- &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
- &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
- &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
-
- &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
- &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
- 0
- };
- return CalleeSavedRegClasses;
-}
-
-BitVector ARMRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
- // FIXME: avoid re-calculating this everytime.
- BitVector Reserved(getNumRegs());
- Reserved.set(ARM::SP);
- Reserved.set(ARM::PC);
- if (STI.isTargetDarwin() || hasFP(MF))
- Reserved.set(FramePtr);
- // Some targets reserve R9.
- if (STI.isR9Reserved())
- Reserved.set(ARM::R9);
- return Reserved;
-}
-
-bool
-ARMRegisterInfo::isReservedReg(const MachineFunction &MF, unsigned Reg) const {
- switch (Reg) {
- default: break;
- case ARM::SP:
- case ARM::PC:
- return true;
- case ARM::R7:
- case ARM::R11:
- if (FramePtr == Reg && (STI.isTargetDarwin() || hasFP(MF)))
- return true;
- break;
- case ARM::R9:
- return STI.isR9Reserved();
- }
-
- return false;
-}
-
-bool
-ARMRegisterInfo::requiresRegisterScavenging(const MachineFunction &MF) const {
- const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- return ThumbRegScavenging || !AFI->isThumbFunction();
-}
-
-/// 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 ARMRegisterInfo::hasFP(const MachineFunction &MF) const {
- return NoFramePointerElim || MF.getFrameInfo()->hasVarSizedObjects();
-}
-
-// hasReservedCallFrame - Under normal circumstances, when a frame pointer is
-// not required, we reserve argument space for call sites in the function
-// immediately on entry to the current function. This eliminates the need for
-// add/sub sp brackets around call sites. Returns true if the call frame is
-// included as part of the stack frame.
-bool ARMRegisterInfo::hasReservedCallFrame(MachineFunction &MF) const {
- const MachineFrameInfo *FFI = MF.getFrameInfo();
- unsigned CFSize = FFI->getMaxCallFrameSize();
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- // It's not always a good idea to include the call frame as part of the
- // stack frame. ARM (especially Thumb) has small immediate offset to
- // address the stack frame. So a large call frame can cause poor codegen
- // and may even makes it impossible to scavenge a register.
- if (AFI->isThumbFunction()) {
- if (CFSize >= ((1 << 8) - 1) * 4 / 2) // Half of imm8 * 4
- return false;
- } else {
- if (CFSize >= ((1 << 12) - 1) / 2) // Half of imm12
- return false;
- }
- return !MF.getFrameInfo()->hasVarSizedObjects();
-}
-
-/// emitARMRegPlusImmediate - Emits a series of instructions to materialize
-/// a destreg = basereg + immediate in ARM code.
-static
-void emitARMRegPlusImmediate(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- unsigned DestReg, unsigned BaseReg, int NumBytes,
- ARMCC::CondCodes Pred, unsigned PredReg,
- const TargetInstrInfo &TII) {
- bool isSub = NumBytes < 0;
- if (isSub) NumBytes = -NumBytes;
-
- while (NumBytes) {
- unsigned RotAmt = ARM_AM::getSOImmValRotate(NumBytes);
- unsigned ThisVal = NumBytes & ARM_AM::rotr32(0xFF, RotAmt);
- assert(ThisVal && "Didn't extract field correctly");
-
- // We will handle these bits from offset, clear them.
- NumBytes &= ~ThisVal;
-
- // Get the properly encoded SOImmVal field.
- int SOImmVal = ARM_AM::getSOImmVal(ThisVal);
- assert(SOImmVal != -1 && "Bit extraction didn't work?");
-
- // Build the new ADD / SUB.
- BuildMI(MBB, MBBI, TII.get(isSub ? ARM::SUBri : ARM::ADDri), DestReg)
- .addReg(BaseReg, false, false, true).addImm(SOImmVal)
- .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
- BaseReg = DestReg;
- }
-}
-
-/// calcNumMI - Returns the number of instructions required to materialize
-/// the specific add / sub r, c instruction.
-static unsigned calcNumMI(int Opc, int ExtraOpc, unsigned Bytes,
- unsigned NumBits, unsigned Scale) {
- unsigned NumMIs = 0;
- unsigned Chunk = ((1 << NumBits) - 1) * Scale;
-
- if (Opc == ARM::tADDrSPi) {
- unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
- Bytes -= ThisVal;
- NumMIs++;
- NumBits = 8;
- Scale = 1; // Followed by a number of tADDi8.
- Chunk = ((1 << NumBits) - 1) * Scale;
- }
-
- NumMIs += Bytes / Chunk;
- if ((Bytes % Chunk) != 0)
- NumMIs++;
- if (ExtraOpc)
- NumMIs++;
- return NumMIs;
-}
-
-/// emitThumbRegPlusImmInReg - Emits a series of instructions to materialize
-/// a destreg = basereg + immediate in Thumb code. Materialize the immediate
-/// in a register using mov / mvn sequences or load the immediate from a
-/// constpool entry.
-static
-void emitThumbRegPlusImmInReg(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- unsigned DestReg, unsigned BaseReg,
- int NumBytes, bool CanChangeCC,
- const TargetInstrInfo &TII) {
- bool isHigh = !isLowRegister(DestReg) ||
- (BaseReg != 0 && !isLowRegister(BaseReg));
- bool isSub = false;
- // Subtract doesn't have high register version. Load the negative value
- // if either base or dest register is a high register. Also, if do not
- // issue sub as part of the sequence if condition register is to be
- // preserved.
- if (NumBytes < 0 && !isHigh && CanChangeCC) {
- isSub = true;
- NumBytes = -NumBytes;
- }
- unsigned LdReg = DestReg;
- if (DestReg == ARM::SP) {
- assert(BaseReg == ARM::SP && "Unexpected!");
- LdReg = ARM::R3;
- BuildMI(MBB, MBBI, TII.get(ARM::tMOVr), ARM::R12)
- .addReg(ARM::R3, false, false, true);
- }
-
- if (NumBytes <= 255 && NumBytes >= 0)
- BuildMI(MBB, MBBI, TII.get(ARM::tMOVi8), LdReg).addImm(NumBytes);
- else if (NumBytes < 0 && NumBytes >= -255) {
- BuildMI(MBB, MBBI, TII.get(ARM::tMOVi8), LdReg).addImm(NumBytes);
- BuildMI(MBB, MBBI, TII.get(ARM::tNEG), LdReg)
- .addReg(LdReg, false, false, true);
- } else
- emitLoadConstPool(MBB, MBBI, LdReg, NumBytes, ARMCC::AL, 0, TII, true);
-
- // Emit add / sub.
- int Opc = (isSub) ? ARM::tSUBrr : (isHigh ? ARM::tADDhirr : ARM::tADDrr);
- const MachineInstrBuilder MIB = BuildMI(MBB, MBBI, TII.get(Opc), DestReg);
- if (DestReg == ARM::SP || isSub)
- MIB.addReg(BaseReg).addReg(LdReg, false, false, true);
- else
- MIB.addReg(LdReg).addReg(BaseReg, false, false, true);
- if (DestReg == ARM::SP)
- BuildMI(MBB, MBBI, TII.get(ARM::tMOVr), ARM::R3)
- .addReg(ARM::R12, false, false, true);
-}
-
-/// emitThumbRegPlusImmediate - Emits a series of instructions to materialize
-/// a destreg = basereg + immediate in Thumb code.
-static
-void emitThumbRegPlusImmediate(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- unsigned DestReg, unsigned BaseReg,
- int NumBytes, const TargetInstrInfo &TII) {
- bool isSub = NumBytes < 0;
- unsigned Bytes = (unsigned)NumBytes;
- if (isSub) Bytes = -NumBytes;
- bool isMul4 = (Bytes & 3) == 0;
- bool isTwoAddr = false;
- bool DstNotEqBase = false;
- unsigned NumBits = 1;
- unsigned Scale = 1;
- int Opc = 0;
- int ExtraOpc = 0;
-
- if (DestReg == BaseReg && BaseReg == ARM::SP) {
- assert(isMul4 && "Thumb sp inc / dec size must be multiple of 4!");
- NumBits = 7;
- Scale = 4;
- Opc = isSub ? ARM::tSUBspi : ARM::tADDspi;
- isTwoAddr = true;
- } else if (!isSub && BaseReg == ARM::SP) {
- // r1 = add sp, 403
- // =>
- // r1 = add sp, 100 * 4
- // r1 = add r1, 3
- if (!isMul4) {
- Bytes &= ~3;
- ExtraOpc = ARM::tADDi3;
- }
- NumBits = 8;
- Scale = 4;
- Opc = ARM::tADDrSPi;
- } else {
- // sp = sub sp, c
- // r1 = sub sp, c
- // r8 = sub sp, c
- if (DestReg != BaseReg)
- DstNotEqBase = true;
- NumBits = 8;
- Opc = isSub ? ARM::tSUBi8 : ARM::tADDi8;
- isTwoAddr = true;
- }
-
- unsigned NumMIs = calcNumMI(Opc, ExtraOpc, Bytes, NumBits, Scale);
- unsigned Threshold = (DestReg == ARM::SP) ? 3 : 2;
- if (NumMIs > Threshold) {
- // This will expand into too many instructions. Load the immediate from a
- // constpool entry.
- emitThumbRegPlusImmInReg(MBB, MBBI, DestReg, BaseReg, NumBytes, true, TII);
- return;
- }
-
- if (DstNotEqBase) {
- if (isLowRegister(DestReg) && isLowRegister(BaseReg)) {
- // If both are low registers, emit DestReg = add BaseReg, max(Imm, 7)
- unsigned Chunk = (1 << 3) - 1;
- unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
- Bytes -= ThisVal;
- BuildMI(MBB, MBBI, TII.get(isSub ? ARM::tSUBi3 : ARM::tADDi3), DestReg)
- .addReg(BaseReg, false, false, true).addImm(ThisVal);
- } else {
- BuildMI(MBB, MBBI, TII.get(ARM::tMOVr), DestReg)
- .addReg(BaseReg, false, false, true);
- }
- BaseReg = DestReg;
- }
-
- unsigned Chunk = ((1 << NumBits) - 1) * Scale;
- while (Bytes) {
- unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
- Bytes -= ThisVal;
- ThisVal /= Scale;
- // Build the new tADD / tSUB.
- if (isTwoAddr)
- BuildMI(MBB, MBBI, TII.get(Opc), DestReg).addReg(DestReg).addImm(ThisVal);
- else {
- bool isKill = BaseReg != ARM::SP;
- BuildMI(MBB, MBBI, TII.get(Opc), DestReg)
- .addReg(BaseReg, false, false, isKill).addImm(ThisVal);
- BaseReg = DestReg;
-
- if (Opc == ARM::tADDrSPi) {
- // r4 = add sp, imm
- // r4 = add r4, imm
- // ...
- NumBits = 8;
- Scale = 1;
- Chunk = ((1 << NumBits) - 1) * Scale;
- Opc = isSub ? ARM::tSUBi8 : ARM::tADDi8;
- isTwoAddr = true;
- }
- }
- }
-
- if (ExtraOpc)
- BuildMI(MBB, MBBI, TII.get(ExtraOpc), DestReg)
- .addReg(DestReg, false, false, true)
- .addImm(((unsigned)NumBytes) & 3);
-}
-
-static
-void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
- int NumBytes, ARMCC::CondCodes Pred, unsigned PredReg,
- bool isThumb, const TargetInstrInfo &TII) {
- if (isThumb)
- emitThumbRegPlusImmediate(MBB, MBBI, ARM::SP, ARM::SP, NumBytes, TII);
- else
- emitARMRegPlusImmediate(MBB, MBBI, ARM::SP, ARM::SP, NumBytes,
- Pred, PredReg, TII);
-}
-
-void ARMRegisterInfo::
-eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
- MachineBasicBlock::iterator I) const {
- if (!hasReservedCallFrame(MF)) {
- // If we have alloca, convert as follows:
- // ADJCALLSTACKDOWN -> sub, sp, sp, amount
- // ADJCALLSTACKUP -> add, sp, sp, amount
- MachineInstr *Old = I;
- unsigned Amount = Old->getOperand(0).getImm();
- if (Amount != 0) {
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- // 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...
- unsigned Opc = Old->getOpcode();
- bool isThumb = AFI->isThumbFunction();
- ARMCC::CondCodes Pred = isThumb
- ? ARMCC::AL : (ARMCC::CondCodes)Old->getOperand(1).getImm();
- if (Opc == ARM::ADJCALLSTACKDOWN || Opc == ARM::tADJCALLSTACKDOWN) {
- // Note: PredReg is operand 2 for ADJCALLSTACKDOWN.
- unsigned PredReg = isThumb ? 0 : Old->getOperand(2).getReg();
- emitSPUpdate(MBB, I, -Amount, Pred, PredReg, isThumb, TII);
- } else {
- // Note: PredReg is operand 3 for ADJCALLSTACKUP.
- unsigned PredReg = isThumb ? 0 : Old->getOperand(3).getReg();
- assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP);
- emitSPUpdate(MBB, I, Amount, Pred, PredReg, isThumb, TII);
- }
- }
- }
- MBB.erase(I);
-}
-
-/// emitThumbConstant - Emit a series of instructions to materialize a
-/// constant.
-static void emitThumbConstant(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- unsigned DestReg, int Imm,
- const TargetInstrInfo &TII) {
- bool isSub = Imm < 0;
- if (isSub) Imm = -Imm;
-
- int Chunk = (1 << 8) - 1;
- int ThisVal = (Imm > Chunk) ? Chunk : Imm;
- Imm -= ThisVal;
- BuildMI(MBB, MBBI, TII.get(ARM::tMOVi8), DestReg).addImm(ThisVal);
- if (Imm > 0)
- emitThumbRegPlusImmediate(MBB, MBBI, DestReg, DestReg, Imm, TII);
- if (isSub)
- BuildMI(MBB, MBBI, TII.get(ARM::tNEG), DestReg)
- .addReg(DestReg, false, false, true);
-}
-
-/// findScratchRegister - Find a 'free' ARM register. If register scavenger
-/// is not being used, R12 is available. Otherwise, try for a call-clobbered
-/// register first and then a spilled callee-saved register if that fails.
-static
-unsigned findScratchRegister(RegScavenger *RS, const TargetRegisterClass *RC,
- ARMFunctionInfo *AFI) {
- unsigned Reg = RS ? RS->FindUnusedReg(RC, true) : (unsigned) ARM::R12;
- if (Reg == 0)
- // Try a already spilled CS register.
- Reg = RS->FindUnusedReg(RC, AFI->getSpilledCSRegisters());
-
- return Reg;
-}
-
-void ARMRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
- int SPAdj, RegScavenger *RS) const{
- unsigned i = 0;
- MachineInstr &MI = *II;
- MachineBasicBlock &MBB = *MI.getParent();
- MachineFunction &MF = *MBB.getParent();
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- bool isThumb = AFI->isThumbFunction();
-
- while (!MI.getOperand(i).isFrameIndex()) {
- ++i;
- assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
- }
-
- unsigned FrameReg = ARM::SP;
- int FrameIndex = MI.getOperand(i).getIndex();
- int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
- MF.getFrameInfo()->getStackSize() + SPAdj;
-
- if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
- Offset -= AFI->getGPRCalleeSavedArea1Offset();
- else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
- Offset -= AFI->getGPRCalleeSavedArea2Offset();
- else if (AFI->isDPRCalleeSavedAreaFrame(FrameIndex))
- Offset -= AFI->getDPRCalleeSavedAreaOffset();
- else if (hasFP(MF)) {
- assert(SPAdj == 0 && "Unexpected");
- // There is alloca()'s in this function, must reference off the frame
- // pointer instead.
- FrameReg = getFrameRegister(MF);
- Offset -= AFI->getFramePtrSpillOffset();
- }
-
- unsigned Opcode = MI.getOpcode();
- const TargetInstrDescriptor &Desc = *MI.getInstrDescriptor();
- unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
- bool isSub = false;
-
- if (Opcode == ARM::ADDri) {
- Offset += MI.getOperand(i+1).getImm();
- if (Offset == 0) {
- // Turn it into a move.
- MI.setInstrDescriptor(TII.get(ARM::MOVr));
- MI.getOperand(i).ChangeToRegister(FrameReg, false);
- MI.RemoveOperand(i+1);
- return;
- } else if (Offset < 0) {
- Offset = -Offset;
- isSub = true;
- MI.setInstrDescriptor(TII.get(ARM::SUBri));
- }
-
- // Common case: small offset, fits into instruction.
- int ImmedOffset = ARM_AM::getSOImmVal(Offset);
- if (ImmedOffset != -1) {
- // Replace the FrameIndex with sp / fp
- MI.getOperand(i).ChangeToRegister(FrameReg, false);
- MI.getOperand(i+1).ChangeToImmediate(ImmedOffset);
- return;
- }
-
- // Otherwise, we fallback to common code below to form the imm offset with
- // a sequence of ADDri instructions. First though, pull as much of the imm
- // into this ADDri as possible.
- unsigned RotAmt = ARM_AM::getSOImmValRotate(Offset);
- unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xFF, RotAmt);
-
- // We will handle these bits from offset, clear them.
- Offset &= ~ThisImmVal;
-
- // Get the properly encoded SOImmVal field.
- int ThisSOImmVal = ARM_AM::getSOImmVal(ThisImmVal);
- assert(ThisSOImmVal != -1 && "Bit extraction didn't work?");
- MI.getOperand(i+1).ChangeToImmediate(ThisSOImmVal);
- } else if (Opcode == ARM::tADDrSPi) {
- Offset += MI.getOperand(i+1).getImm();
-
- // Can't use tADDrSPi if it's based off the frame pointer.
- unsigned NumBits = 0;
- unsigned Scale = 1;
- if (FrameReg != ARM::SP) {
- Opcode = ARM::tADDi3;
- MI.setInstrDescriptor(TII.get(ARM::tADDi3));
- NumBits = 3;
- } else {
- NumBits = 8;
- Scale = 4;
- assert((Offset & 3) == 0 &&
- "Thumb add/sub sp, #imm immediate must be multiple of 4!");
- }
-
- if (Offset == 0) {
- // Turn it into a move.
- MI.setInstrDescriptor(TII.get(ARM::tMOVr));
- MI.getOperand(i).ChangeToRegister(FrameReg, false);
- MI.RemoveOperand(i+1);
- return;
- }
-
- // Common case: small offset, fits into instruction.
- unsigned Mask = (1 << NumBits) - 1;
- if (((Offset / Scale) & ~Mask) == 0) {
- // Replace the FrameIndex with sp / fp
- MI.getOperand(i).ChangeToRegister(FrameReg, false);
- MI.getOperand(i+1).ChangeToImmediate(Offset / Scale);
- return;
- }
-
- unsigned DestReg = MI.getOperand(0).getReg();
- unsigned Bytes = (Offset > 0) ? Offset : -Offset;
- unsigned NumMIs = calcNumMI(Opcode, 0, Bytes, NumBits, Scale);
- // MI would expand into a large number of instructions. Don't try to
- // simplify the immediate.
- if (NumMIs > 2) {
- emitThumbRegPlusImmediate(MBB, II, DestReg, FrameReg, Offset, TII);
- MBB.erase(II);
- return;
- }
-
- if (Offset > 0) {
- // Translate r0 = add sp, imm to
- // r0 = add sp, 255*4
- // r0 = add r0, (imm - 255*4)
- MI.getOperand(i).ChangeToRegister(FrameReg, false);
- MI.getOperand(i+1).ChangeToImmediate(Mask);
- Offset = (Offset - Mask * Scale);
- MachineBasicBlock::iterator NII = next(II);
- emitThumbRegPlusImmediate(MBB, NII, DestReg, DestReg, Offset, TII);
- } else {
- // Translate r0 = add sp, -imm to
- // r0 = -imm (this is then translated into a series of instructons)
- // r0 = add r0, sp
- emitThumbConstant(MBB, II, DestReg, Offset, TII);
- MI.setInstrDescriptor(TII.get(ARM::tADDhirr));
- MI.getOperand(i).ChangeToRegister(DestReg, false, false, true);
- MI.getOperand(i+1).ChangeToRegister(FrameReg, false);
- }
- return;
- } else {
- unsigned ImmIdx = 0;
- int InstrOffs = 0;
- unsigned NumBits = 0;
- unsigned Scale = 1;
- switch (AddrMode) {
- case ARMII::AddrMode2: {
- ImmIdx = i+2;
- InstrOffs = ARM_AM::getAM2Offset(MI.getOperand(ImmIdx).getImm());
- if (ARM_AM::getAM2Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
- InstrOffs *= -1;
- NumBits = 12;
- break;
- }
- case ARMII::AddrMode3: {
- ImmIdx = i+2;
- InstrOffs = ARM_AM::getAM3Offset(MI.getOperand(ImmIdx).getImm());
- if (ARM_AM::getAM3Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
- InstrOffs *= -1;
- NumBits = 8;
- break;
- }
- case ARMII::AddrMode5: {
- ImmIdx = i+1;
- InstrOffs = ARM_AM::getAM5Offset(MI.getOperand(ImmIdx).getImm());
- if (ARM_AM::getAM5Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
- InstrOffs *= -1;
- NumBits = 8;
- Scale = 4;
- break;
- }
- case ARMII::AddrModeTs: {
- ImmIdx = i+1;
- InstrOffs = MI.getOperand(ImmIdx).getImm();
- NumBits = (FrameReg == ARM::SP) ? 8 : 5;
- Scale = 4;
- break;
- }
- default:
- assert(0 && "Unsupported addressing mode!");
- abort();
- break;
- }
-
- Offset += InstrOffs * Scale;
- assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
- if (Offset < 0 && !isThumb) {
- Offset = -Offset;
- isSub = true;
- }
-
- // Common case: small offset, fits into instruction.
- MachineOperand &ImmOp = MI.getOperand(ImmIdx);
- int ImmedOffset = Offset / Scale;
- unsigned Mask = (1 << NumBits) - 1;
- if ((unsigned)Offset <= Mask * Scale) {
- // Replace the FrameIndex with sp
- MI.getOperand(i).ChangeToRegister(FrameReg, false);
- if (isSub)
- ImmedOffset |= 1 << NumBits;
- ImmOp.ChangeToImmediate(ImmedOffset);
- return;
- }
-
- bool isThumSpillRestore = Opcode == ARM::tRestore || Opcode == ARM::tSpill;
- if (AddrMode == ARMII::AddrModeTs) {
- // Thumb tLDRspi, tSTRspi. These will change to instructions that use
- // a different base register.
- NumBits = 5;
- Mask = (1 << NumBits) - 1;
- }
- // If this is a thumb spill / restore, we will be using a constpool load to
- // materialize the offset.
- if (AddrMode == ARMII::AddrModeTs && isThumSpillRestore)
- ImmOp.ChangeToImmediate(0);
- else {
- // Otherwise, it didn't fit. Pull in what we can to simplify the immed.
- ImmedOffset = ImmedOffset & Mask;
- if (isSub)
- ImmedOffset |= 1 << NumBits;
- ImmOp.ChangeToImmediate(ImmedOffset);
- Offset &= ~(Mask*Scale);
- }
- }
-
- // If we get here, the immediate doesn't fit into the instruction. We folded
- // as much as possible above, handle the rest, providing a register that is
- // SP+LargeImm.
- assert(Offset && "This code isn't needed if offset already handled!");
-
- if (isThumb) {
- if (Desc.isSimpleLoad()) {
- // Use the destination register to materialize sp + offset.
- unsigned TmpReg = MI.getOperand(0).getReg();
- bool UseRR = false;
- if (Opcode == ARM::tRestore) {
- if (FrameReg == ARM::SP)
- emitThumbRegPlusImmInReg(MBB, II, TmpReg, FrameReg,Offset,false,TII);
- else {
- emitLoadConstPool(MBB, II, TmpReg, Offset, ARMCC::AL, 0, TII, true);
- UseRR = true;
- }
- } else
- emitThumbRegPlusImmediate(MBB, II, TmpReg, FrameReg, Offset, TII);
- MI.setInstrDescriptor(TII.get(ARM::tLDR));
- MI.getOperand(i).ChangeToRegister(TmpReg, false, false, true);
- if (UseRR)
- // Use [reg, reg] addrmode.
- MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
- else // tLDR has an extra register operand.
- MI.addOperand(MachineOperand::CreateReg(0, false));
- } else if (TII.mayStore(Opcode)) {
- // FIXME! This is horrific!!! We need register scavenging.
- // Our temporary workaround has marked r3 unavailable. Of course, r3 is
- // also a ABI register so it's possible that is is the register that is
- // being storing here. If that's the case, we do the following:
- // r12 = r2
- // Use r2 to materialize sp + offset
- // str r3, r2
- // r2 = r12
- unsigned ValReg = MI.getOperand(0).getReg();
- unsigned TmpReg = ARM::R3;
- bool UseRR = false;
- if (ValReg == ARM::R3) {
- BuildMI(MBB, II, TII.get(ARM::tMOVr), ARM::R12)
- .addReg(ARM::R2, false, false, true);
- TmpReg = ARM::R2;
- }
- if (TmpReg == ARM::R3 && AFI->isR3LiveIn())
- BuildMI(MBB, II, TII.get(ARM::tMOVr), ARM::R12)
- .addReg(ARM::R3, false, false, true);
- if (Opcode == ARM::tSpill) {
- if (FrameReg == ARM::SP)
- emitThumbRegPlusImmInReg(MBB, II, TmpReg, FrameReg,Offset,false,TII);
- else {
- emitLoadConstPool(MBB, II, TmpReg, Offset, ARMCC::AL, 0, TII, true);
- UseRR = true;
- }
- } else
- emitThumbRegPlusImmediate(MBB, II, TmpReg, FrameReg, Offset, TII);
- MI.setInstrDescriptor(TII.get(ARM::tSTR));
- MI.getOperand(i).ChangeToRegister(TmpReg, false, false, true);
- if (UseRR) // Use [reg, reg] addrmode.
- MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
- else // tSTR has an extra register operand.
- MI.addOperand(MachineOperand::CreateReg(0, false));
-
- MachineBasicBlock::iterator NII = next(II);
- if (ValReg == ARM::R3)
- BuildMI(MBB, NII, TII.get(ARM::tMOVr), ARM::R2)
- .addReg(ARM::R12, false, false, true);
- if (TmpReg == ARM::R3 && AFI->isR3LiveIn())
- BuildMI(MBB, NII, TII.get(ARM::tMOVr), ARM::R3)
- .addReg(ARM::R12, false, false, true);
- } else
- assert(false && "Unexpected opcode!");
- } else {
- // Insert a set of r12 with the full address: r12 = sp + offset
- // If the offset we have is too large to fit into the instruction, we need
- // to form it with a series of ADDri's. Do this by taking 8-bit chunks
- // out of 'Offset'.
- unsigned ScratchReg = findScratchRegister(RS, &ARM::GPRRegClass, AFI);
- if (ScratchReg == 0)
- // No register is "free". Scavenge a register.
- ScratchReg = RS->scavengeRegister(&ARM::GPRRegClass, II, SPAdj);
- int PIdx = MI.findFirstPredOperandIdx();
- ARMCC::CondCodes Pred = (PIdx == -1)
- ? ARMCC::AL : (ARMCC::CondCodes)MI.getOperand(PIdx).getImm();
- unsigned PredReg = (PIdx == -1) ? 0 : MI.getOperand(PIdx+1).getReg();
- emitARMRegPlusImmediate(MBB, II, ScratchReg, FrameReg,
- isSub ? -Offset : Offset, Pred, PredReg, TII);
- MI.getOperand(i).ChangeToRegister(ScratchReg, false, false, true);
- }
-}
-
-static unsigned estimateStackSize(MachineFunction &MF, MachineFrameInfo *MFI) {
- const MachineFrameInfo *FFI = MF.getFrameInfo();
- int Offset = 0;
- for (int i = FFI->getObjectIndexBegin(); i != 0; ++i) {
- int FixedOff = -FFI->getObjectOffset(i);
- if (FixedOff > Offset) Offset = FixedOff;
- }
- for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
- Offset += FFI->getObjectSize(i);
- unsigned Align = FFI->getObjectAlignment(i);
- // Adjust to alignment boundary
- Offset = (Offset+Align-1)/Align*Align;
- }
- return (unsigned)Offset;
-}
-
-void
-ARMRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
- RegScavenger *RS) const {
- // This tells PEI to spill the FP as if it is any other callee-save register
- // to take advantage the eliminateFrameIndex machinery. This also ensures it
- // is spilled in the order specified by getCalleeSavedRegs() to make it easier
- // to combine multiple loads / stores.
- bool CanEliminateFrame = true;
- bool CS1Spilled = false;
- bool LRSpilled = false;
- unsigned NumGPRSpills = 0;
- SmallVector<unsigned, 4> UnspilledCS1GPRs;
- SmallVector<unsigned, 4> UnspilledCS2GPRs;
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
-
- // Don't spill FP if the frame can be eliminated. This is determined
- // by scanning the callee-save registers to see if any is used.
- const unsigned *CSRegs = getCalleeSavedRegs();
- const TargetRegisterClass* const *CSRegClasses = getCalleeSavedRegClasses();
- for (unsigned i = 0; CSRegs[i]; ++i) {
- unsigned Reg = CSRegs[i];
- bool Spilled = false;
- if (MF.getRegInfo().isPhysRegUsed(Reg)) {
- AFI->setCSRegisterIsSpilled(Reg);
- Spilled = true;
- CanEliminateFrame = false;
- } else {
- // Check alias registers too.
- for (const unsigned *Aliases = getAliasSet(Reg); *Aliases; ++Aliases) {
- if (MF.getRegInfo().isPhysRegUsed(*Aliases)) {
- Spilled = true;
- CanEliminateFrame = false;
- }
- }
- }
-
- if (CSRegClasses[i] == &ARM::GPRRegClass) {
- if (Spilled) {
- NumGPRSpills++;
-
- if (!STI.isTargetDarwin()) {
- if (Reg == ARM::LR)
- LRSpilled = true;
- CS1Spilled = true;
- continue;
- }
-
- // Keep track if LR and any of R4, R5, R6, and R7 is spilled.
- switch (Reg) {
- case ARM::LR:
- LRSpilled = true;
- // Fallthrough
- case ARM::R4:
- case ARM::R5:
- case ARM::R6:
- case ARM::R7:
- CS1Spilled = true;
- break;
- default:
- break;
- }
- } else {
- if (!STI.isTargetDarwin()) {
- UnspilledCS1GPRs.push_back(Reg);
- continue;
- }
-
- switch (Reg) {
- case ARM::R4:
- case ARM::R5:
- case ARM::R6:
- case ARM::R7:
- case ARM::LR:
- UnspilledCS1GPRs.push_back(Reg);
- break;
- default:
- UnspilledCS2GPRs.push_back(Reg);
- break;
- }
- }
- }
- }
-
- bool ForceLRSpill = false;
- if (!LRSpilled && AFI->isThumbFunction()) {
- unsigned FnSize = ARM::GetFunctionSize(MF);
- // Force LR to be spilled if the Thumb function size is > 2048. This enables
- // use of BL to implement far jump. If it turns out that it's not needed
- // then the branch fix up path will undo it.
- if (FnSize >= (1 << 11)) {
- CanEliminateFrame = false;
- ForceLRSpill = true;
- }
- }
-
- bool ExtraCSSpill = false;
- if (!CanEliminateFrame || hasFP(MF)) {
- AFI->setHasStackFrame(true);
-
- // If LR is not spilled, but at least one of R4, R5, R6, and R7 is spilled.
- // Spill LR as well so we can fold BX_RET to the registers restore (LDM).
- if (!LRSpilled && CS1Spilled) {
- MF.getRegInfo().setPhysRegUsed(ARM::LR);
- AFI->setCSRegisterIsSpilled(ARM::LR);
- NumGPRSpills++;
- UnspilledCS1GPRs.erase(std::find(UnspilledCS1GPRs.begin(),
- UnspilledCS1GPRs.end(), (unsigned)ARM::LR));
- ForceLRSpill = false;
- ExtraCSSpill = true;
- }
-
- // Darwin ABI requires FP to point to the stack slot that contains the
- // previous FP.
- if (STI.isTargetDarwin() || hasFP(MF)) {
- MF.getRegInfo().setPhysRegUsed(FramePtr);
- NumGPRSpills++;
- }
-
- // If stack and double are 8-byte aligned and we are spilling an odd number
- // of GPRs. Spill one extra callee save GPR so we won't have to pad between
- // the integer and double callee save areas.
- unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
- if (TargetAlign == 8 && (NumGPRSpills & 1)) {
- if (CS1Spilled && !UnspilledCS1GPRs.empty()) {
- for (unsigned i = 0, e = UnspilledCS1GPRs.size(); i != e; ++i) {
- unsigned Reg = UnspilledCS1GPRs[i];
- // Don't spiil high register if the function is thumb
- if (!AFI->isThumbFunction() || isLowRegister(Reg) || Reg == ARM::LR) {
- MF.getRegInfo().setPhysRegUsed(Reg);
- AFI->setCSRegisterIsSpilled(Reg);
- if (!isReservedReg(MF, Reg))
- ExtraCSSpill = true;
- break;
- }
- }
- } else if (!UnspilledCS2GPRs.empty() &&
- !AFI->isThumbFunction()) {
- unsigned Reg = UnspilledCS2GPRs.front();
- MF.getRegInfo().setPhysRegUsed(Reg);
- AFI->setCSRegisterIsSpilled(Reg);
- if (!isReservedReg(MF, Reg))
- ExtraCSSpill = true;
- }
- }
-
- // Estimate if we might need to scavenge a register at some point in order
- // to materialize a stack offset. If so, either spill one additiona
- // callee-saved register or reserve a special spill slot to facilitate
- // register scavenging.
- if (RS && !ExtraCSSpill && !AFI->isThumbFunction()) {
- MachineFrameInfo *MFI = MF.getFrameInfo();
- unsigned Size = estimateStackSize(MF, MFI);
- unsigned Limit = (1 << 12) - 1;
- for (MachineFunction::iterator BB = MF.begin(),E = MF.end();BB != E; ++BB)
- for (MachineBasicBlock::iterator I= BB->begin(); I != BB->end(); ++I) {
- for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
- if (I->getOperand(i).isFrameIndex()) {
- unsigned Opcode = I->getOpcode();
- const TargetInstrDescriptor &Desc = TII.get(Opcode);
- unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
- if (AddrMode == ARMII::AddrMode3) {
- Limit = (1 << 8) - 1;
- goto DoneEstimating;
- } else if (AddrMode == ARMII::AddrMode5) {
- unsigned ThisLimit = ((1 << 8) - 1) * 4;
- if (ThisLimit < Limit)
- Limit = ThisLimit;
- }
- }
- }
- DoneEstimating:
- if (Size >= Limit) {
- // If any non-reserved CS register isn't spilled, just spill one or two
- // extra. That should take care of it!
- unsigned NumExtras = TargetAlign / 4;
- SmallVector<unsigned, 2> Extras;
- while (NumExtras && !UnspilledCS1GPRs.empty()) {
- unsigned Reg = UnspilledCS1GPRs.back();
- UnspilledCS1GPRs.pop_back();
- if (!isReservedReg(MF, Reg)) {
- Extras.push_back(Reg);
- NumExtras--;
- }
- }
- while (NumExtras && !UnspilledCS2GPRs.empty()) {
- unsigned Reg = UnspilledCS2GPRs.back();
- UnspilledCS2GPRs.pop_back();
- if (!isReservedReg(MF, Reg)) {
- Extras.push_back(Reg);
- NumExtras--;
- }
- }
- if (Extras.size() && NumExtras == 0) {
- for (unsigned i = 0, e = Extras.size(); i != e; ++i) {
- MF.getRegInfo().setPhysRegUsed(Extras[i]);
- AFI->setCSRegisterIsSpilled(Extras[i]);
- }
- } else {
- // Reserve a slot closest to SP or frame pointer.
- const TargetRegisterClass *RC = &ARM::GPRRegClass;
- RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
- RC->getAlignment()));
- }
- }
- }
- }
-
- if (ForceLRSpill) {
- MF.getRegInfo().setPhysRegUsed(ARM::LR);
- AFI->setCSRegisterIsSpilled(ARM::LR);
- AFI->setLRIsSpilledForFarJump(true);
- }
-}
-
-/// Move iterator pass the next bunch of callee save load / store ops for
-/// the particular spill area (1: integer area 1, 2: integer area 2,
-/// 3: fp area, 0: don't care).
-static void movePastCSLoadStoreOps(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- int Opc, unsigned Area,
- const ARMSubtarget &STI) {
- while (MBBI != MBB.end() &&
- MBBI->getOpcode() == Opc && MBBI->getOperand(1).isFrameIndex()) {
- if (Area != 0) {
- bool Done = false;
- unsigned Category = 0;
- switch (MBBI->getOperand(0).getReg()) {
- case ARM::R4: case ARM::R5: case ARM::R6: case ARM::R7:
- case ARM::LR:
- Category = 1;
- break;
- case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11:
- Category = STI.isTargetDarwin() ? 2 : 1;
- break;
- case ARM::D8: case ARM::D9: case ARM::D10: case ARM::D11:
- case ARM::D12: case ARM::D13: case ARM::D14: case ARM::D15:
- Category = 3;
- break;
- default:
- Done = true;
- break;
- }
- if (Done || Category != Area)
- break;
- }
-
- ++MBBI;
- }
-}
-
-void ARMRegisterInfo::emitPrologue(MachineFunction &MF) const {
- MachineBasicBlock &MBB = MF.front();
- MachineBasicBlock::iterator MBBI = MBB.begin();
- MachineFrameInfo *MFI = MF.getFrameInfo();
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- bool isThumb = AFI->isThumbFunction();
- unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
- unsigned NumBytes = MFI->getStackSize();
- const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
-
- if (isThumb) {
- // Check if R3 is live in. It might have to be used as a scratch register.
- for (MachineRegisterInfo::livein_iterator I =MF.getRegInfo().livein_begin(),
- E = MF.getRegInfo().livein_end(); I != E; ++I) {
- if (I->first == ARM::R3) {
- AFI->setR3IsLiveIn(true);
- break;
- }
- }
-
- // Thumb add/sub sp, imm8 instructions implicitly multiply the offset by 4.
- NumBytes = (NumBytes + 3) & ~3;
- MFI->setStackSize(NumBytes);
- }
-
- // Determine the sizes of each callee-save spill areas and record which frame
- // belongs to which callee-save spill areas.
- unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
- int FramePtrSpillFI = 0;
-
- if (VARegSaveSize)
- emitSPUpdate(MBB, MBBI, -VARegSaveSize, ARMCC::AL, 0, isThumb, TII);
-
- if (!AFI->hasStackFrame()) {
- if (NumBytes != 0)
- emitSPUpdate(MBB, MBBI, -NumBytes, ARMCC::AL, 0, isThumb, TII);
- return;
- }
-
- for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
- unsigned Reg = CSI[i].getReg();
- int FI = CSI[i].getFrameIdx();
- switch (Reg) {
- case ARM::R4:
- case ARM::R5:
- case ARM::R6:
- case ARM::R7:
- case ARM::LR:
- if (Reg == FramePtr)
- FramePtrSpillFI = FI;
- AFI->addGPRCalleeSavedArea1Frame(FI);
- GPRCS1Size += 4;
- break;
- case ARM::R8:
- case ARM::R9:
- case ARM::R10:
- case ARM::R11:
- if (Reg == FramePtr)
- FramePtrSpillFI = FI;
- if (STI.isTargetDarwin()) {
- AFI->addGPRCalleeSavedArea2Frame(FI);
- GPRCS2Size += 4;
- } else {
- AFI->addGPRCalleeSavedArea1Frame(FI);
- GPRCS1Size += 4;
- }
- break;
- default:
- AFI->addDPRCalleeSavedAreaFrame(FI);
- DPRCSSize += 8;
- }
- }
-
- if (!isThumb) {
- // Build the new SUBri to adjust SP for integer callee-save spill area 1.
- emitSPUpdate(MBB, MBBI, -GPRCS1Size, ARMCC::AL, 0, isThumb, TII);
- movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, 1, STI);
- } else if (MBBI != MBB.end() && MBBI->getOpcode() == ARM::tPUSH)
- ++MBBI;
-
- // Darwin ABI requires FP to point to the stack slot that contains the
- // previous FP.
- if (STI.isTargetDarwin() || hasFP(MF)) {
- MachineInstrBuilder MIB =
- BuildMI(MBB, MBBI, TII.get(isThumb ? ARM::tADDrSPi : ARM::ADDri),FramePtr)
- .addFrameIndex(FramePtrSpillFI).addImm(0);
- if (!isThumb) AddDefaultCC(AddDefaultPred(MIB));
- }
-
- if (!isThumb) {
- // Build the new SUBri to adjust SP for integer callee-save spill area 2.
- emitSPUpdate(MBB, MBBI, -GPRCS2Size, ARMCC::AL, 0, false, TII);
-
- // Build the new SUBri to adjust SP for FP callee-save spill area.
- movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, 2, STI);
- emitSPUpdate(MBB, MBBI, -DPRCSSize, ARMCC::AL, 0, false, TII);
- }
-
- // Determine starting offsets of spill areas.
- unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
- unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
- unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
- AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) + NumBytes);
- AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
- AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
- AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
-
- NumBytes = DPRCSOffset;
- if (NumBytes) {
- // Insert it after all the callee-save spills.
- if (!isThumb)
- movePastCSLoadStoreOps(MBB, MBBI, ARM::FSTD, 3, STI);
- emitSPUpdate(MBB, MBBI, -NumBytes, ARMCC::AL, 0, isThumb, TII);
- }
-
- if(STI.isTargetELF() && hasFP(MF)) {
- MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
- AFI->getFramePtrSpillOffset());
- }
-
- AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
- AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
- AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
-}
-
-static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) {
- for (unsigned i = 0; CSRegs[i]; ++i)
- if (Reg == CSRegs[i])
- return true;
- return false;
-}
-
-static bool isCSRestore(MachineInstr *MI, const unsigned *CSRegs) {
- return ((MI->getOpcode() == ARM::FLDD ||
- MI->getOpcode() == ARM::LDR ||
- MI->getOpcode() == ARM::tRestore) &&
- MI->getOperand(1).isFrameIndex() &&
- isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs));
-}
-
-void ARMRegisterInfo::emitEpilogue(MachineFunction &MF,
- MachineBasicBlock &MBB) const {
- MachineBasicBlock::iterator MBBI = prior(MBB.end());
- assert((MBBI->getOpcode() == ARM::BX_RET ||
- MBBI->getOpcode() == ARM::tBX_RET ||
- MBBI->getOpcode() == ARM::tPOP_RET) &&
- "Can only insert epilog into returning blocks");
-
- MachineFrameInfo *MFI = MF.getFrameInfo();
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- bool isThumb = AFI->isThumbFunction();
- unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
- int NumBytes = (int)MFI->getStackSize();
- if (!AFI->hasStackFrame()) {
- if (NumBytes != 0)
- emitSPUpdate(MBB, MBBI, NumBytes, ARMCC::AL, 0, isThumb, TII);
- } else {
- // Unwind MBBI to point to first LDR / FLDD.
- const unsigned *CSRegs = getCalleeSavedRegs();
- if (MBBI != MBB.begin()) {
- do
- --MBBI;
- while (MBBI != MBB.begin() && isCSRestore(MBBI, CSRegs));
- if (!isCSRestore(MBBI, CSRegs))
- ++MBBI;
- }
-
- // Move SP to start of FP callee save spill area.
- NumBytes -= (AFI->getGPRCalleeSavedArea1Size() +
- AFI->getGPRCalleeSavedArea2Size() +
- AFI->getDPRCalleeSavedAreaSize());
- if (isThumb) {
- if (hasFP(MF)) {
- NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;
- // Reset SP based on frame pointer only if the stack frame extends beyond
- // frame pointer stack slot or target is ELF and the function has FP.
- if (NumBytes)
- emitThumbRegPlusImmediate(MBB, MBBI, ARM::SP, FramePtr, -NumBytes, TII);
- else
- BuildMI(MBB, MBBI, TII.get(ARM::tMOVr), ARM::SP).addReg(FramePtr);
- } else {
- if (MBBI->getOpcode() == ARM::tBX_RET &&
- &MBB.front() != MBBI &&
- prior(MBBI)->getOpcode() == ARM::tPOP) {
- MachineBasicBlock::iterator PMBBI = prior(MBBI);
- emitSPUpdate(MBB, PMBBI, NumBytes, ARMCC::AL, 0, isThumb, TII);
- } else
- emitSPUpdate(MBB, MBBI, NumBytes, ARMCC::AL, 0, isThumb, TII);
- }
- } else {
- // Darwin ABI requires FP to point to the stack slot that contains the
- // previous FP.
- if ((STI.isTargetDarwin() && NumBytes) || hasFP(MF)) {
- NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;
- // Reset SP based on frame pointer only if the stack frame extends beyond
- // frame pointer stack slot or target is ELF and the function has FP.
- if (AFI->getGPRCalleeSavedArea2Size() ||
- AFI->getDPRCalleeSavedAreaSize() ||
- AFI->getDPRCalleeSavedAreaOffset()||
- hasFP(MF))
- if (NumBytes)
- BuildMI(MBB, MBBI, TII.get(ARM::SUBri), ARM::SP).addReg(FramePtr)
- .addImm(NumBytes)
- .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
- else
- BuildMI(MBB, MBBI, TII.get(ARM::MOVr), ARM::SP).addReg(FramePtr)
- .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
- } else if (NumBytes) {
- emitSPUpdate(MBB, MBBI, NumBytes, ARMCC::AL, 0, false, TII);
- }
-
- // Move SP to start of integer callee save spill area 2.
- movePastCSLoadStoreOps(MBB, MBBI, ARM::FLDD, 3, STI);
- emitSPUpdate(MBB, MBBI, AFI->getDPRCalleeSavedAreaSize(), ARMCC::AL, 0,
- false, TII);
-
- // Move SP to start of integer callee save spill area 1.
- movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, 2, STI);
- emitSPUpdate(MBB, MBBI, AFI->getGPRCalleeSavedArea2Size(), ARMCC::AL, 0,
- false, TII);
-
- // Move SP to SP upon entry to the function.
- movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, 1, STI);
- emitSPUpdate(MBB, MBBI, AFI->getGPRCalleeSavedArea1Size(), ARMCC::AL, 0,
- false, TII);
- }
- }
-
- if (VARegSaveSize) {
- if (isThumb)
- // Epilogue for vararg functions: pop LR to R3 and branch off it.
- // FIXME: Verify this is still ok when R3 is no longer being reserved.
- BuildMI(MBB, MBBI, TII.get(ARM::tPOP)).addReg(ARM::R3);
-
- emitSPUpdate(MBB, MBBI, VARegSaveSize, ARMCC::AL, 0, isThumb, TII);
-
- if (isThumb) {
- BuildMI(MBB, MBBI, TII.get(ARM::tBX_RET_vararg)).addReg(ARM::R3);
- MBB.erase(MBBI);
- }
- }
-}
-
-unsigned ARMRegisterInfo::getRARegister() const {
- return ARM::LR;
-}
-
-unsigned ARMRegisterInfo::getFrameRegister(MachineFunction &MF) const {
- if (STI.isTargetDarwin() || hasFP(MF))
- return (STI.useThumbBacktraces() || STI.isThumb()) ? ARM::R7 : ARM::R11;
- else
- return ARM::SP;
-}
-
-unsigned ARMRegisterInfo::getEHExceptionRegister() const {
- assert(0 && "What is the exception register");
- return 0;
-}
-
-unsigned ARMRegisterInfo::getEHHandlerRegister() const {
- assert(0 && "What is the exception handler register");
- return 0;
-}
-
-int ARMRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
- assert(0 && "What is the dwarf register number");
- return -1;
-}
-
-#include "ARMGenRegisterInfo.inc"
+void ARMRegisterInfo::anchor() { }
+ARMRegisterInfo::ARMRegisterInfo() : ARMBaseRegisterInfo() {}
projects / oota-llvm.git / blobdiff