X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTarget%2FARM%2FARMBaseRegisterInfo.cpp;h=827cb64d14c2b30a4008631ec2221a11f5d259f8;hb=2766a47310b05228e9bbc536d9f3a593fc31cd12;hp=c0c95fea131dfc46e3ff4e1d6e767d0707dd93af;hpb=ff28103b192a7e818f92628c2a4e34e622c1a142;p=oota-llvm.git diff --git a/lib/Target/ARM/ARMBaseRegisterInfo.cpp b/lib/Target/ARM/ARMBaseRegisterInfo.cpp index c0c95fea131..827cb64d14c 100644 --- a/lib/Target/ARM/ARMBaseRegisterInfo.cpp +++ b/lib/Target/ARM/ARMBaseRegisterInfo.cpp @@ -1,4 +1,4 @@ -//===- ARMBaseRegisterInfo.cpp - ARM Register Information -------*- C++ -*-===// +//===-- ARMBaseRegisterInfo.cpp - ARM Register Information ----------------===// // // The LLVM Compiler Infrastructure // @@ -11,447 +11,227 @@ // //===----------------------------------------------------------------------===// +#include "ARMBaseRegisterInfo.h" #include "ARM.h" -#include "ARMAddressingModes.h" #include "ARMBaseInstrInfo.h" -#include "ARMBaseRegisterInfo.h" -#include "ARMInstrInfo.h" +#include "ARMFrameLowering.h" #include "ARMMachineFunctionInfo.h" #include "ARMSubtarget.h" -#include "llvm/Constants.h" -#include "llvm/DerivedTypes.h" -#include "llvm/Function.h" -#include "llvm/LLVMContext.h" +#include "MCTargetDesc/ARMAddressingModes.h" +#include "llvm/ADT/BitVector.h" +#include "llvm/ADT/SmallVector.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/CodeGen/VirtRegMap.h" +#include "llvm/Constants.h" +#include "llvm/DerivedTypes.h" +#include "llvm/Function.h" +#include "llvm/LLVMContext.h" +#include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" -#include "llvm/Target/TargetFrameInfo.h" +#include "llvm/Target/TargetFrameLowering.h" #include "llvm/Target/TargetMachine.h" #include "llvm/Target/TargetOptions.h" -#include "llvm/ADT/BitVector.h" -#include "llvm/ADT/SmallVector.h" -#include "llvm/Support/CommandLine.h" -using namespace llvm; -static cl::opt -ReuseFrameIndexVals("arm-reuse-frame-index-vals", cl::Hidden, cl::init(true), - cl::desc("Reuse repeated frame index values")); +#define GET_REGINFO_TARGET_DESC +#include "ARMGenRegisterInfo.inc" -unsigned ARMBaseRegisterInfo::getRegisterNumbering(unsigned RegEnum, - bool *isSPVFP) { - if (isSPVFP) - *isSPVFP = false; +using namespace llvm; - using namespace ARM; - switch (RegEnum) { - default: - llvm_unreachable("Unknown ARM register!"); - case R0: case D0: case Q0: return 0; - case R1: case D1: case Q1: return 1; - case R2: case D2: case Q2: return 2; - case R3: case D3: case Q3: return 3; - case R4: case D4: case Q4: return 4; - case R5: case D5: case Q5: return 5; - case R6: case D6: case Q6: return 6; - case R7: case D7: case Q7: return 7; - case R8: case D8: case Q8: return 8; - case R9: case D9: case Q9: return 9; - case R10: case D10: case Q10: return 10; - case R11: case D11: case Q11: return 11; - case R12: case D12: case Q12: return 12; - case SP: case D13: case Q13: return 13; - case LR: case D14: case Q14: return 14; - case PC: case D15: case Q15: return 15; - - case D16: return 16; - case D17: return 17; - case D18: return 18; - case D19: return 19; - case D20: return 20; - case D21: return 21; - case D22: return 22; - case D23: return 23; - case D24: return 24; - case D25: return 25; - case D26: return 27; - case D27: return 27; - case D28: return 28; - case D29: return 29; - case D30: return 30; - case D31: return 31; - - case S0: case S1: case S2: case S3: - case S4: case S5: case S6: case S7: - case S8: case S9: case S10: case S11: - case S12: case S13: case S14: case S15: - case S16: case S17: case S18: case S19: - case S20: case S21: case S22: case S23: - case S24: case S25: case S26: case S27: - case S28: case S29: case S30: case S31: { - if (isSPVFP) - *isSPVFP = true; - switch (RegEnum) { - default: return 0; // Avoid compile time warning. - case S0: return 0; - case S1: return 1; - case S2: return 2; - case S3: return 3; - case S4: return 4; - case S5: return 5; - case S6: return 6; - case S7: return 7; - case S8: return 8; - case S9: return 9; - case S10: return 10; - case S11: return 11; - case S12: return 12; - case S13: return 13; - case S14: return 14; - case S15: 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; - } - } - } -} +static cl::opt +ForceAllBaseRegAlloc("arm-force-base-reg-alloc", cl::Hidden, cl::init(false), + cl::desc("Force use of virtual base registers for stack load/store")); +static cl::opt +EnableLocalStackAlloc("enable-local-stack-alloc", cl::init(true), cl::Hidden, + cl::desc("Enable pre-regalloc stack frame index allocation")); +static cl::opt +EnableBasePointer("arm-use-base-pointer", cl::Hidden, cl::init(true), + cl::desc("Enable use of a base pointer for complex stack frames")); ARMBaseRegisterInfo::ARMBaseRegisterInfo(const ARMBaseInstrInfo &tii, const ARMSubtarget &sti) - : ARMGenRegisterInfo(ARM::ADJCALLSTACKDOWN, ARM::ADJCALLSTACKUP), - TII(tii), STI(sti), - FramePtr((STI.isTargetDarwin() || STI.isThumb()) ? ARM::R7 : ARM::R11) { + : ARMGenRegisterInfo(ARM::LR), TII(tii), STI(sti), + FramePtr((STI.isTargetDarwin() || STI.isThumb()) ? ARM::R7 : ARM::R11), + BasePtr(ARM::R6) { } -const unsigned* +const uint16_t* ARMBaseRegisterInfo::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[] = { - // Darwin ABI deviates from ARM standard ABI. R9 is not a callee-saved - // register. - ARM::LR, ARM::R7, ARM::R6, ARM::R5, ARM::R4, - ARM::R11, ARM::R10, ARM::R8, - - ARM::D15, ARM::D14, ARM::D13, ARM::D12, - ARM::D11, ARM::D10, ARM::D9, ARM::D8, - 0 - }; - return STI.isTargetDarwin() ? DarwinCalleeSavedRegs : CalleeSavedRegs; + bool ghcCall = false; + + if (MF) { + const Function *F = MF->getFunction(); + ghcCall = (F ? F->getCallingConv() == CallingConv::GHC : false); + } + + if (ghcCall) { + return CSR_GHC_SaveList; + } + else { + return (STI.isTargetIOS() && !STI.isAAPCS_ABI()) + ? CSR_iOS_SaveList : CSR_AAPCS_SaveList; + } } -const TargetRegisterClass* const * -ARMBaseRegisterInfo::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 - }; - - static const TargetRegisterClass * const ThumbCalleeSavedRegClasses[] = { - &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass, - &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::tGPRRegClass, - &ARM::tGPRRegClass,&ARM::tGPRRegClass,&ARM::tGPRRegClass, - - &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, - &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, - 0 - }; - - static const TargetRegisterClass * const DarwinCalleeSavedRegClasses[] = { - &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 - }; - - static const TargetRegisterClass * const DarwinThumbCalleeSavedRegClasses[] ={ - &ARM::GPRRegClass, &ARM::tGPRRegClass, &ARM::tGPRRegClass, - &ARM::tGPRRegClass, &ARM::tGPRRegClass, &ARM::GPRRegClass, - &ARM::GPRRegClass, &ARM::GPRRegClass, - - &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, - &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, - 0 - }; - - if (STI.isThumb1Only()) { - return STI.isTargetDarwin() - ? DarwinThumbCalleeSavedRegClasses : ThumbCalleeSavedRegClasses; - } - return STI.isTargetDarwin() - ? DarwinCalleeSavedRegClasses : CalleeSavedRegClasses; +const uint32_t* +ARMBaseRegisterInfo::getCallPreservedMask(CallingConv::ID) const { + return (STI.isTargetIOS() && !STI.isAAPCS_ABI()) + ? CSR_iOS_RegMask : CSR_AAPCS_RegMask; +} + +const uint32_t* +ARMBaseRegisterInfo::getNoPreservedMask() const { + return CSR_NoRegs_RegMask; } BitVector ARMBaseRegisterInfo:: getReservedRegs(const MachineFunction &MF) const { - // FIXME: avoid re-calculating this everytime. + const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering(); + + // FIXME: avoid re-calculating this every time. BitVector Reserved(getNumRegs()); Reserved.set(ARM::SP); Reserved.set(ARM::PC); - if (STI.isTargetDarwin() || hasFP(MF)) + Reserved.set(ARM::FPSCR); + if (TFI->hasFP(MF)) Reserved.set(FramePtr); + if (hasBasePointer(MF)) + Reserved.set(BasePtr); // Some targets reserve R9. if (STI.isR9Reserved()) Reserved.set(ARM::R9); - return Reserved; -} - -bool ARMBaseRegisterInfo::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(); + // Reserve D16-D31 if the subtarget doesn't support them. + if (!STI.hasVFP3() || STI.hasD16()) { + assert(ARM::D31 == ARM::D16 + 15); + for (unsigned i = 0; i != 16; ++i) + Reserved.set(ARM::D16 + i); } + const TargetRegisterClass *RC = &ARM::GPRPairRegClass; + for(TargetRegisterClass::iterator I = RC->begin(), E = RC->end(); I!=E; ++I) + for (MCSubRegIterator SI(*I, this); SI.isValid(); ++SI) + if (Reserved.test(*SI)) Reserved.set(*I); - return false; + return Reserved; } -const TargetRegisterClass * -ARMBaseRegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A, - const TargetRegisterClass *B, - unsigned SubIdx) const { - switch (SubIdx) { - default: return 0; - case 1: - case 2: - case 3: - case 4: - // S sub-registers. - if (A->getSize() == 8) { - if (B == &ARM::SPR_8RegClass) - return &ARM::DPR_8RegClass; - assert(B == &ARM::SPRRegClass && "Expecting SPR register class!"); - if (A == &ARM::DPR_8RegClass) - return A; - return &ARM::DPR_VFP2RegClass; +const TargetRegisterClass* +ARMBaseRegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC) + const { + const TargetRegisterClass *Super = RC; + TargetRegisterClass::sc_iterator I = RC->getSuperClasses(); + do { + switch (Super->getID()) { + case ARM::GPRRegClassID: + case ARM::SPRRegClassID: + case ARM::DPRRegClassID: + case ARM::QPRRegClassID: + case ARM::QQPRRegClassID: + case ARM::QQQQPRRegClassID: + case ARM::GPRPairRegClassID: + return Super; } - - assert(A->getSize() == 16 && "Expecting a Q register class!"); - if (B == &ARM::SPR_8RegClass) - return &ARM::QPR_8RegClass; - return &ARM::QPR_VFP2RegClass; - case 5: - case 6: - // D sub-registers. - if (B == &ARM::DPR_VFP2RegClass) - return &ARM::QPR_VFP2RegClass; - if (B == &ARM::DPR_8RegClass) - return &ARM::QPR_8RegClass; - return A; - } - return 0; + Super = *I++; + } while (Super); + return RC; } const TargetRegisterClass * -ARMBaseRegisterInfo::getPointerRegClass(unsigned Kind) const { - return ARM::GPRRegisterClass; +ARMBaseRegisterInfo::getPointerRegClass(const MachineFunction &MF, unsigned Kind) + const { + return &ARM::GPRRegClass; } -/// getAllocationOrder - Returns the register allocation order for a specified -/// register class in the form of a pair of TargetRegisterClass iterators. -std::pair -ARMBaseRegisterInfo::getAllocationOrder(const TargetRegisterClass *RC, - unsigned HintType, unsigned HintReg, - const MachineFunction &MF) const { - // Alternative register allocation orders when favoring even / odd registers - // of register pairs. - - // No FP, R9 is available. - static const unsigned GPREven1[] = { - ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R8, ARM::R10, - ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R7, - ARM::R9, ARM::R11 - }; - static const unsigned GPROdd1[] = { - ARM::R1, ARM::R3, ARM::R5, ARM::R7, ARM::R9, ARM::R11, - ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, - ARM::R8, ARM::R10 - }; - - // FP is R7, R9 is available. - static const unsigned GPREven2[] = { - ARM::R0, ARM::R2, ARM::R4, ARM::R8, ARM::R10, - ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R6, - ARM::R9, ARM::R11 - }; - static const unsigned GPROdd2[] = { - ARM::R1, ARM::R3, ARM::R5, ARM::R9, ARM::R11, - ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, - ARM::R8, ARM::R10 - }; - - // FP is R11, R9 is available. - static const unsigned GPREven3[] = { - ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R8, - ARM::R1, ARM::R3, ARM::R10,ARM::R12,ARM::LR, ARM::R5, ARM::R7, - ARM::R9 - }; - static const unsigned GPROdd3[] = { - ARM::R1, ARM::R3, ARM::R5, ARM::R6, ARM::R9, - ARM::R0, ARM::R2, ARM::R10,ARM::R12,ARM::LR, ARM::R4, ARM::R7, - ARM::R8 - }; - - // No FP, R9 is not available. - static const unsigned GPREven4[] = { - ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R10, - ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R7, ARM::R8, - ARM::R11 - }; - static const unsigned GPROdd4[] = { - ARM::R1, ARM::R3, ARM::R5, ARM::R7, ARM::R11, - ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8, - ARM::R10 - }; - - // FP is R7, R9 is not available. - static const unsigned GPREven5[] = { - ARM::R0, ARM::R2, ARM::R4, ARM::R10, - ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R6, ARM::R8, - ARM::R11 - }; - static const unsigned GPROdd5[] = { - ARM::R1, ARM::R3, ARM::R5, ARM::R11, - ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8, - ARM::R10 - }; - - // FP is R11, R9 is not available. - static const unsigned GPREven6[] = { - ARM::R0, ARM::R2, ARM::R4, ARM::R6, - ARM::R1, ARM::R3, ARM::R10,ARM::R12,ARM::LR, ARM::R5, ARM::R7, ARM::R8 - }; - static const unsigned GPROdd6[] = { - ARM::R1, ARM::R3, ARM::R5, ARM::R7, - ARM::R0, ARM::R2, ARM::R10,ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8 - }; - - - if (HintType == ARMRI::RegPairEven) { - if (isPhysicalRegister(HintReg) && getRegisterPairEven(HintReg, MF) == 0) - // It's no longer possible to fulfill this hint. Return the default - // allocation order. - return std::make_pair(RC->allocation_order_begin(MF), - RC->allocation_order_end(MF)); - - if (!STI.isTargetDarwin() && !hasFP(MF)) { - if (!STI.isR9Reserved()) - return std::make_pair(GPREven1, - GPREven1 + (sizeof(GPREven1)/sizeof(unsigned))); - else - return std::make_pair(GPREven4, - GPREven4 + (sizeof(GPREven4)/sizeof(unsigned))); - } else if (FramePtr == ARM::R7) { - if (!STI.isR9Reserved()) - return std::make_pair(GPREven2, - GPREven2 + (sizeof(GPREven2)/sizeof(unsigned))); - else - return std::make_pair(GPREven5, - GPREven5 + (sizeof(GPREven5)/sizeof(unsigned))); - } else { // FramePtr == ARM::R11 - if (!STI.isR9Reserved()) - return std::make_pair(GPREven3, - GPREven3 + (sizeof(GPREven3)/sizeof(unsigned))); - else - return std::make_pair(GPREven6, - GPREven6 + (sizeof(GPREven6)/sizeof(unsigned))); - } - } else if (HintType == ARMRI::RegPairOdd) { - if (isPhysicalRegister(HintReg) && getRegisterPairOdd(HintReg, MF) == 0) - // It's no longer possible to fulfill this hint. Return the default - // allocation order. - return std::make_pair(RC->allocation_order_begin(MF), - RC->allocation_order_end(MF)); - - if (!STI.isTargetDarwin() && !hasFP(MF)) { - if (!STI.isR9Reserved()) - return std::make_pair(GPROdd1, - GPROdd1 + (sizeof(GPROdd1)/sizeof(unsigned))); - else - return std::make_pair(GPROdd4, - GPROdd4 + (sizeof(GPROdd4)/sizeof(unsigned))); - } else if (FramePtr == ARM::R7) { - if (!STI.isR9Reserved()) - return std::make_pair(GPROdd2, - GPROdd2 + (sizeof(GPROdd2)/sizeof(unsigned))); - else - return std::make_pair(GPROdd5, - GPROdd5 + (sizeof(GPROdd5)/sizeof(unsigned))); - } else { // FramePtr == ARM::R11 - if (!STI.isR9Reserved()) - return std::make_pair(GPROdd3, - GPROdd3 + (sizeof(GPROdd3)/sizeof(unsigned))); - else - return std::make_pair(GPROdd6, - GPROdd6 + (sizeof(GPROdd6)/sizeof(unsigned))); - } - } - return std::make_pair(RC->allocation_order_begin(MF), - RC->allocation_order_end(MF)); +const TargetRegisterClass * +ARMBaseRegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const { + if (RC == &ARM::CCRRegClass) + return 0; // Can't copy CCR registers. + return RC; } -/// ResolveRegAllocHint - Resolves the specified register allocation hint -/// to a physical register. Returns the physical register if it is successful. unsigned -ARMBaseRegisterInfo::ResolveRegAllocHint(unsigned Type, unsigned Reg, - const MachineFunction &MF) const { - if (Reg == 0 || !isPhysicalRegister(Reg)) +ARMBaseRegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC, + MachineFunction &MF) const { + const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering(); + + switch (RC->getID()) { + default: return 0; - if (Type == 0) - return Reg; - else if (Type == (unsigned)ARMRI::RegPairOdd) - // Odd register. - return getRegisterPairOdd(Reg, MF); - else if (Type == (unsigned)ARMRI::RegPairEven) - // Even register. - return getRegisterPairEven(Reg, MF); + case ARM::tGPRRegClassID: + return TFI->hasFP(MF) ? 4 : 5; + case ARM::GPRRegClassID: { + unsigned FP = TFI->hasFP(MF) ? 1 : 0; + return 10 - FP - (STI.isR9Reserved() ? 1 : 0); + } + case ARM::SPRRegClassID: // Currently not used as 'rep' register class. + case ARM::DPRRegClassID: + return 32 - 10; + } +} + +// Get the other register in a GPRPair. +static unsigned getPairedGPR(unsigned Reg, bool Odd, const MCRegisterInfo *RI) { + for (MCSuperRegIterator Supers(Reg, RI); Supers.isValid(); ++Supers) + if (ARM::GPRPairRegClass.contains(*Supers)) + return RI->getSubReg(*Supers, Odd ? ARM::gsub_1 : ARM::gsub_0); return 0; } +// Resolve the RegPairEven / RegPairOdd register allocator hints. +void +ARMBaseRegisterInfo::getRegAllocationHints(unsigned VirtReg, + ArrayRef Order, + SmallVectorImpl &Hints, + const MachineFunction &MF, + const VirtRegMap *VRM) const { + const MachineRegisterInfo &MRI = MF.getRegInfo(); + std::pair Hint = MRI.getRegAllocationHint(VirtReg); + + unsigned Odd; + switch (Hint.first) { + case ARMRI::RegPairEven: + Odd = 0; + break; + case ARMRI::RegPairOdd: + Odd = 1; + break; + default: + TargetRegisterInfo::getRegAllocationHints(VirtReg, Order, Hints, MF, VRM); + return; + } + + // This register should preferably be even (Odd == 0) or odd (Odd == 1). + // Check if the other part of the pair has already been assigned, and provide + // the paired register as the first hint. + unsigned PairedPhys = 0; + if (VRM && VRM->hasPhys(Hint.second)) { + PairedPhys = getPairedGPR(VRM->getPhys(Hint.second), Odd, this); + if (PairedPhys && MRI.isReserved(PairedPhys)) + PairedPhys = 0; + } + + // First prefer the paired physreg. + if (PairedPhys) + Hints.push_back(PairedPhys); + + // Then prefer even or odd registers. + for (unsigned I = 0, E = Order.size(); I != E; ++I) { + unsigned Reg = Order[I]; + if (Reg == PairedPhys || (getEncodingValue(Reg) & 1) != Odd) + continue; + // Don't provide hints that are paired to a reserved register. + unsigned Paired = getPairedGPR(Reg, !Odd, this); + if (!Paired || MRI.isReserved(Paired)) + continue; + Hints.push_back(Reg); + } +} + void ARMBaseRegisterInfo::UpdateRegAllocHint(unsigned Reg, unsigned NewReg, MachineFunction &MF) const { @@ -459,7 +239,7 @@ ARMBaseRegisterInfo::UpdateRegAllocHint(unsigned Reg, unsigned NewReg, std::pair Hint = MRI->getRegAllocationHint(Reg); if ((Hint.first == (unsigned)ARMRI::RegPairOdd || Hint.first == (unsigned)ARMRI::RegPairEven) && - Hint.second && TargetRegisterInfo::isVirtualRegister(Hint.second)) { + TargetRegisterInfo::isVirtualRegister(Hint.second)) { // If 'Reg' is one of the even / odd register pair and it's now changed // (e.g. coalesced) into a different register. The other register of the // pair allocation hint must be updated to reflect the relationship @@ -472,567 +252,125 @@ ARMBaseRegisterInfo::UpdateRegAllocHint(unsigned Reg, unsigned NewReg, } } -/// 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 ARMBaseRegisterInfo::hasFP(const MachineFunction &MF) const { +bool +ARMBaseRegisterInfo::avoidWriteAfterWrite(const TargetRegisterClass *RC) const { + // CortexA9 has a Write-after-write hazard for NEON registers. + if (!STI.isLikeA9()) + return false; + + switch (RC->getID()) { + case ARM::DPRRegClassID: + case ARM::DPR_8RegClassID: + case ARM::DPR_VFP2RegClassID: + case ARM::QPRRegClassID: + case ARM::QPR_8RegClassID: + case ARM::QPR_VFP2RegClassID: + case ARM::SPRRegClassID: + case ARM::SPR_8RegClassID: + // Avoid reusing S, D, and Q registers. + // Don't increase register pressure for QQ and QQQQ. + return true; + default: + return false; + } +} + +bool ARMBaseRegisterInfo::hasBasePointer(const MachineFunction &MF) const { const MachineFrameInfo *MFI = MF.getFrameInfo(); - return ((NoFramePointerElim && MFI->hasCalls())|| - needsStackRealignment(MF) || - MFI->hasVarSizedObjects() || - MFI->isFrameAddressTaken()); + const ARMFunctionInfo *AFI = MF.getInfo(); + const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering(); + + if (!EnableBasePointer) + return false; + + // When outgoing call frames are so large that we adjust the stack pointer + // around the call, we can no longer use the stack pointer to reach the + // emergency spill slot. + if (needsStackRealignment(MF) && !TFI->hasReservedCallFrame(MF)) + return true; + + // Thumb has trouble with negative offsets from the FP. Thumb2 has a limited + // negative range for ldr/str (255), and thumb1 is positive offsets only. + // It's going to be better to use the SP or Base Pointer instead. When there + // are variable sized objects, we can't reference off of the SP, so we + // reserve a Base Pointer. + if (AFI->isThumbFunction() && MFI->hasVarSizedObjects()) { + // Conservatively estimate whether the negative offset from the frame + // pointer will be sufficient to reach. If a function has a smallish + // frame, it's less likely to have lots of spills and callee saved + // space, so it's all more likely to be within range of the frame pointer. + // If it's wrong, the scavenger will still enable access to work, it just + // won't be optimal. + if (AFI->isThumb2Function() && MFI->getLocalFrameSize() < 128) + return false; + return true; + } + + return false; } bool ARMBaseRegisterInfo::canRealignStack(const MachineFunction &MF) const { - const MachineFrameInfo *MFI = MF.getFrameInfo(); + const MachineRegisterInfo *MRI = &MF.getRegInfo(); const ARMFunctionInfo *AFI = MF.getInfo(); - return (RealignStack && - !AFI->isThumb1OnlyFunction() && - !MFI->hasVarSizedObjects()); + // We can't realign the stack if: + // 1. Dynamic stack realignment is explicitly disabled, + // 2. This is a Thumb1 function (it's not useful, so we don't bother), or + // 3. There are VLAs in the function and the base pointer is disabled. + if (!MF.getTarget().Options.RealignStack) + return false; + if (AFI->isThumb1OnlyFunction()) + return false; + // Stack realignment requires a frame pointer. If we already started + // register allocation with frame pointer elimination, it is too late now. + if (!MRI->canReserveReg(FramePtr)) + return false; + // We may also need a base pointer if there are dynamic allocas or stack + // pointer adjustments around calls. + if (MF.getTarget().getFrameLowering()->hasReservedCallFrame(MF)) + return true; + if (!EnableBasePointer) + return false; + // A base pointer is required and allowed. Check that it isn't too late to + // reserve it. + return MRI->canReserveReg(BasePtr); } bool ARMBaseRegisterInfo:: needsStackRealignment(const MachineFunction &MF) const { const MachineFrameInfo *MFI = MF.getFrameInfo(); - const ARMFunctionInfo *AFI = MF.getInfo(); - unsigned StackAlign = MF.getTarget().getFrameInfo()->getStackAlignment(); - return (RealignStack && - !AFI->isThumb1OnlyFunction() && - (MFI->getMaxAlignment() > StackAlign) && - !MFI->hasVarSizedObjects()); + const Function *F = MF.getFunction(); + unsigned StackAlign = MF.getTarget().getFrameLowering()->getStackAlignment(); + bool requiresRealignment = + ((MFI->getMaxAlignment() > StackAlign) || + F->getFnAttributes().hasAttribute(Attributes::StackAlignment)); + + return requiresRealignment && canRealignStack(MF); } bool ARMBaseRegisterInfo:: cannotEliminateFrame(const MachineFunction &MF) const { const MachineFrameInfo *MFI = MF.getFrameInfo(); - if (NoFramePointerElim && MFI->hasCalls()) + if (MF.getTarget().Options.DisableFramePointerElim(MF) && MFI->adjustsStack()) return true; return MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken() || needsStackRealignment(MF); } -/// estimateStackSize - Estimate and return the size of the frame. -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) { - if (FFI->isDeadObjectIndex(i)) - continue; - Offset += FFI->getObjectSize(i); - unsigned Align = FFI->getObjectAlignment(i); - // Adjust to alignment boundary - Offset = (Offset+Align-1)/Align*Align; - } - return (unsigned)Offset; -} - -/// estimateRSStackSizeLimit - Look at each instruction that references stack -/// frames and return the stack size limit beyond which some of these -/// instructions will require a scratch register during their expansion later. unsigned -ARMBaseRegisterInfo::estimateRSStackSizeLimit(MachineFunction &MF) const { - unsigned Limit = (1 << 12) - 1; - for (MachineFunction::iterator BB = MF.begin(),E = MF.end(); BB != E; ++BB) { - for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end(); - I != E; ++I) { - for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) { - if (!I->getOperand(i).isFI()) continue; - - const TargetInstrDesc &Desc = TII.get(I->getOpcode()); - unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask); - if (AddrMode == ARMII::AddrMode3 || - AddrMode == ARMII::AddrModeT2_i8) - return (1 << 8) - 1; - - if (AddrMode == ARMII::AddrMode5 || - AddrMode == ARMII::AddrModeT2_i8s4) - Limit = std::min(Limit, ((1U << 8) - 1) * 4); - - if (AddrMode == ARMII::AddrModeT2_i12 && hasFP(MF)) - // When the stack offset is negative, we will end up using - // the i8 instructions instead. - return (1 << 8) - 1; - - if (AddrMode == ARMII::AddrMode6) - return 0; - break; // At most one FI per instruction - } - } - } - - return Limit; -} - -void -ARMBaseRegisterInfo::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 UnspilledCS1GPRs; - SmallVector UnspilledCS2GPRs; - ARMFunctionInfo *AFI = MF.getInfo(); - - // Spill R4 if Thumb2 function requires stack realignment - it will be used as - // scratch register. - // FIXME: It will be better just to find spare register here. - if (needsStackRealignment(MF) && - AFI->isThumb2Function()) - MF.getRegInfo().setPhysRegUsed(ARM::R4); - - // 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::GPRRegisterClass || - CSRegClasses[i] == ARM::tGPRRegisterClass) { - 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->isThumb1OnlyFunction()) { - unsigned FnSize = TII.GetFunctionSizeInBytes(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 || cannotEliminateFrame(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 spill high register if the function is thumb1 - if (!AFI->isThumb1OnlyFunction() || - isARMLowRegister(Reg) || Reg == ARM::LR) { - MF.getRegInfo().setPhysRegUsed(Reg); - AFI->setCSRegisterIsSpilled(Reg); - if (!isReservedReg(MF, Reg)) - ExtraCSSpill = true; - break; - } - } - } else if (!UnspilledCS2GPRs.empty() && - !AFI->isThumb1OnlyFunction()) { - 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 additional - // callee-saved register or reserve a special spill slot to facilitate - // register scavenging. Thumb1 needs a spill slot for stack pointer - // adjustments also, even when the frame itself is small. - if (RS && !ExtraCSSpill) { - MachineFrameInfo *MFI = MF.getFrameInfo(); - // If any of the stack slot references may be out of range of an - // immediate offset, make sure a register (or a spill slot) is - // available for the register scavenger. Note that if we're indexing - // off the frame pointer, the effective stack size is 4 bytes larger - // since the FP points to the stack slot of the previous FP. - if (estimateStackSize(MF, MFI) + (hasFP(MF) ? 4 : 0) - >= estimateRSStackSizeLimit(MF)) { - // 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 Extras; - while (NumExtras && !UnspilledCS1GPRs.empty()) { - unsigned Reg = UnspilledCS1GPRs.back(); - UnspilledCS1GPRs.pop_back(); - if (!isReservedReg(MF, Reg)) { - Extras.push_back(Reg); - NumExtras--; - } - } - // For non-Thumb1 functions, also check for hi-reg CS registers - if (!AFI->isThumb1OnlyFunction()) { - 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 if (!AFI->isThumb1OnlyFunction()) { - // note: Thumb1 functions spill to R12, not the stack. - // Reserve a slot closest to SP or frame pointer. - const TargetRegisterClass *RC = ARM::GPRRegisterClass; - RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(), - RC->getAlignment(), - false)); - } - } - } - } - - if (ForceLRSpill) { - MF.getRegInfo().setPhysRegUsed(ARM::LR); - AFI->setCSRegisterIsSpilled(ARM::LR); - AFI->setLRIsSpilledForFarJump(true); - } -} - -unsigned ARMBaseRegisterInfo::getRARegister() const { - return ARM::LR; -} - -unsigned ARMBaseRegisterInfo::getFrameRegister(const MachineFunction &MF) const { - if (STI.isTargetDarwin() || hasFP(MF)) + const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering(); + + if (TFI->hasFP(MF)) return FramePtr; return ARM::SP; } -int -ARMBaseRegisterInfo::getFrameIndexReference(const MachineFunction &MF, int FI, - unsigned &FrameReg) const { - const MachineFrameInfo *MFI = MF.getFrameInfo(); - const ARMFunctionInfo *AFI = MF.getInfo(); - int Offset = MFI->getObjectOffset(FI) + MFI->getStackSize(); - bool isFixed = MFI->isFixedObjectIndex(FI); - - FrameReg = ARM::SP; - if (AFI->isGPRCalleeSavedArea1Frame(FI)) - Offset -= AFI->getGPRCalleeSavedArea1Offset(); - else if (AFI->isGPRCalleeSavedArea2Frame(FI)) - Offset -= AFI->getGPRCalleeSavedArea2Offset(); - else if (AFI->isDPRCalleeSavedAreaFrame(FI)) - Offset -= AFI->getDPRCalleeSavedAreaOffset(); - else if (needsStackRealignment(MF)) { - // When dynamically realigning the stack, use the frame pointer for - // parameters, and the stack pointer for locals. - assert (hasFP(MF) && "dynamic stack realignment without a FP!"); - if (isFixed) { - FrameReg = getFrameRegister(MF); - Offset -= AFI->getFramePtrSpillOffset(); - } - } else if (hasFP(MF) && AFI->hasStackFrame()) { - if (isFixed || MFI->hasVarSizedObjects()) { - // Use frame pointer to reference fixed objects unless this is a - // frameless function. - FrameReg = getFrameRegister(MF); - Offset -= AFI->getFramePtrSpillOffset(); - } else if (AFI->isThumb2Function()) { - // In Thumb2 mode, the negative offset is very limited. - int FPOffset = Offset - AFI->getFramePtrSpillOffset(); - if (FPOffset >= -255 && FPOffset < 0) { - FrameReg = getFrameRegister(MF); - Offset = FPOffset; - } - } - } - return Offset; -} - - -int -ARMBaseRegisterInfo::getFrameIndexOffset(const MachineFunction &MF, - int FI) const { - unsigned FrameReg; - return getFrameIndexReference(MF, FI, FrameReg); -} - unsigned ARMBaseRegisterInfo::getEHExceptionRegister() const { llvm_unreachable("What is the exception register"); - return 0; } unsigned ARMBaseRegisterInfo::getEHHandlerRegister() const { llvm_unreachable("What is the exception handler register"); - return 0; -} - -int ARMBaseRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const { - return ARMGenRegisterInfo::getDwarfRegNumFull(RegNum, 0); -} - -unsigned ARMBaseRegisterInfo::getRegisterPairEven(unsigned Reg, - const MachineFunction &MF) const { - switch (Reg) { - default: break; - // Return 0 if either register of the pair is a special register. - // So no R12, etc. - case ARM::R1: - return ARM::R0; - case ARM::R3: - return ARM::R2; - case ARM::R5: - return ARM::R4; - case ARM::R7: - return isReservedReg(MF, ARM::R7) ? 0 : ARM::R6; - case ARM::R9: - return isReservedReg(MF, ARM::R9) ? 0 :ARM::R8; - case ARM::R11: - return isReservedReg(MF, ARM::R11) ? 0 : ARM::R10; - - case ARM::S1: - return ARM::S0; - case ARM::S3: - return ARM::S2; - case ARM::S5: - return ARM::S4; - case ARM::S7: - return ARM::S6; - case ARM::S9: - return ARM::S8; - case ARM::S11: - return ARM::S10; - case ARM::S13: - return ARM::S12; - case ARM::S15: - return ARM::S14; - case ARM::S17: - return ARM::S16; - case ARM::S19: - return ARM::S18; - case ARM::S21: - return ARM::S20; - case ARM::S23: - return ARM::S22; - case ARM::S25: - return ARM::S24; - case ARM::S27: - return ARM::S26; - case ARM::S29: - return ARM::S28; - case ARM::S31: - return ARM::S30; - - case ARM::D1: - return ARM::D0; - case ARM::D3: - return ARM::D2; - case ARM::D5: - return ARM::D4; - case ARM::D7: - return ARM::D6; - case ARM::D9: - return ARM::D8; - case ARM::D11: - return ARM::D10; - case ARM::D13: - return ARM::D12; - case ARM::D15: - return ARM::D14; - case ARM::D17: - return ARM::D16; - case ARM::D19: - return ARM::D18; - case ARM::D21: - return ARM::D20; - case ARM::D23: - return ARM::D22; - case ARM::D25: - return ARM::D24; - case ARM::D27: - return ARM::D26; - case ARM::D29: - return ARM::D28; - case ARM::D31: - return ARM::D30; - } - - return 0; -} - -unsigned ARMBaseRegisterInfo::getRegisterPairOdd(unsigned Reg, - const MachineFunction &MF) const { - switch (Reg) { - default: break; - // Return 0 if either register of the pair is a special register. - // So no R12, etc. - case ARM::R0: - return ARM::R1; - case ARM::R2: - return ARM::R3; - case ARM::R4: - return ARM::R5; - case ARM::R6: - return isReservedReg(MF, ARM::R7) ? 0 : ARM::R7; - case ARM::R8: - return isReservedReg(MF, ARM::R9) ? 0 :ARM::R9; - case ARM::R10: - return isReservedReg(MF, ARM::R11) ? 0 : ARM::R11; - - case ARM::S0: - return ARM::S1; - case ARM::S2: - return ARM::S3; - case ARM::S4: - return ARM::S5; - case ARM::S6: - return ARM::S7; - case ARM::S8: - return ARM::S9; - case ARM::S10: - return ARM::S11; - case ARM::S12: - return ARM::S13; - case ARM::S14: - return ARM::S15; - case ARM::S16: - return ARM::S17; - case ARM::S18: - return ARM::S19; - case ARM::S20: - return ARM::S21; - case ARM::S22: - return ARM::S23; - case ARM::S24: - return ARM::S25; - case ARM::S26: - return ARM::S27; - case ARM::S28: - return ARM::S29; - case ARM::S30: - return ARM::S31; - - case ARM::D0: - return ARM::D1; - case ARM::D2: - return ARM::D3; - case ARM::D4: - return ARM::D5; - case ARM::D6: - return ARM::D7; - case ARM::D8: - return ARM::D9; - case ARM::D10: - return ARM::D11; - case ARM::D12: - return ARM::D13; - case ARM::D14: - return ARM::D15; - case ARM::D16: - return ARM::D17; - case ARM::D18: - return ARM::D19; - case ARM::D20: - return ARM::D21; - case ARM::D22: - return ARM::D23; - case ARM::D24: - return ARM::D25; - case ARM::D26: - return ARM::D27; - case ARM::D28: - return ARM::D29; - case ARM::D30: - return ARM::D31; - } - - return 0; } /// emitLoadConstPool - Emits a load from constpool to materialize the @@ -1043,17 +381,18 @@ emitLoadConstPool(MachineBasicBlock &MBB, DebugLoc dl, unsigned DestReg, unsigned SubIdx, int Val, ARMCC::CondCodes Pred, - unsigned PredReg) const { + unsigned PredReg, unsigned MIFlags) const { MachineFunction &MF = *MBB.getParent(); MachineConstantPool *ConstantPool = MF.getConstantPool(); - Constant *C = + const Constant *C = ConstantInt::get(Type::getInt32Ty(MF.getFunction()->getContext()), Val); unsigned Idx = ConstantPool->getConstantPoolIndex(C, 4); BuildMI(MBB, MBBI, dl, TII.get(ARM::LDRcp)) .addReg(DestReg, getDefRegState(true), SubIdx) .addConstantPoolIndex(Idx) - .addReg(0).addImm(0).addImm(Pred).addReg(PredReg); + .addImm(0).addImm(Pred).addReg(PredReg) + .setMIFlags(MIFlags); } bool ARMBaseRegisterInfo:: @@ -1062,36 +401,18 @@ requiresRegisterScavenging(const MachineFunction &MF) const { } bool ARMBaseRegisterInfo:: -requiresFrameIndexScavenging(const MachineFunction &MF) const { +trackLivenessAfterRegAlloc(const MachineFunction &MF) const { return true; } -// 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 ARMBaseRegisterInfo:: -hasReservedCallFrame(MachineFunction &MF) const { - const MachineFrameInfo *FFI = MF.getFrameInfo(); - unsigned CFSize = FFI->getMaxCallFrameSize(); - // 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 (CFSize >= ((1 << 12) - 1) / 2) // Half of imm12 - return false; - - return !MF.getFrameInfo()->hasVarSizedObjects(); +requiresFrameIndexScavenging(const MachineFunction &MF) const { + return true; } -// canSimplifyCallFramePseudos - If there is a reserved call frame, the -// call frame pseudos can be simplified. Unlike most targets, having a FP -// is not sufficient here since we still may reference some objects via SP -// even when FP is available in Thumb2 mode. bool ARMBaseRegisterInfo:: -canSimplifyCallFramePseudos(MachineFunction &MF) const { - return hasReservedCallFrame(MF) || MF.getFrameInfo()->hasVarSizedObjects(); +requiresVirtualBaseRegisters(const MachineFunction &MF) const { + return EnableLocalStackAlloc; } static void @@ -1112,7 +433,8 @@ emitSPUpdate(bool isARM, void ARMBaseRegisterInfo:: eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, MachineBasicBlock::iterator I) const { - if (!hasReservedCallFrame(MF)) { + const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering(); + if (!TFI->hasReservedCallFrame(MF)) { // If we have alloca, convert as follows: // ADJCALLSTACKDOWN -> sub, sp, sp, amount // ADJCALLSTACKUP -> add, sp, sp, amount @@ -1123,7 +445,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, // 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(); + unsigned Align = TFI->getStackAlignment(); Amount = (Amount+Align-1)/Align*Align; ARMFunctionInfo *AFI = MF.getInfo(); @@ -1151,14 +473,274 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, MBB.erase(I); } -unsigned +int64_t ARMBaseRegisterInfo:: +getFrameIndexInstrOffset(const MachineInstr *MI, int Idx) const { + const MCInstrDesc &Desc = MI->getDesc(); + unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask); + int64_t InstrOffs = 0; + int Scale = 1; + unsigned ImmIdx = 0; + switch (AddrMode) { + case ARMII::AddrModeT2_i8: + case ARMII::AddrModeT2_i12: + case ARMII::AddrMode_i12: + InstrOffs = MI->getOperand(Idx+1).getImm(); + Scale = 1; + break; + case ARMII::AddrMode5: { + // VFP address mode. + const MachineOperand &OffOp = MI->getOperand(Idx+1); + InstrOffs = ARM_AM::getAM5Offset(OffOp.getImm()); + if (ARM_AM::getAM5Op(OffOp.getImm()) == ARM_AM::sub) + InstrOffs = -InstrOffs; + Scale = 4; + break; + } + case ARMII::AddrMode2: { + ImmIdx = Idx+2; + InstrOffs = ARM_AM::getAM2Offset(MI->getOperand(ImmIdx).getImm()); + if (ARM_AM::getAM2Op(MI->getOperand(ImmIdx).getImm()) == ARM_AM::sub) + InstrOffs = -InstrOffs; + break; + } + case ARMII::AddrMode3: { + ImmIdx = Idx+2; + InstrOffs = ARM_AM::getAM3Offset(MI->getOperand(ImmIdx).getImm()); + if (ARM_AM::getAM3Op(MI->getOperand(ImmIdx).getImm()) == ARM_AM::sub) + InstrOffs = -InstrOffs; + break; + } + case ARMII::AddrModeT1_s: { + ImmIdx = Idx+1; + InstrOffs = MI->getOperand(ImmIdx).getImm(); + Scale = 4; + break; + } + default: + llvm_unreachable("Unsupported addressing mode!"); + } + + return InstrOffs * Scale; +} + +/// needsFrameBaseReg - Returns true if the instruction's frame index +/// reference would be better served by a base register other than FP +/// or SP. Used by LocalStackFrameAllocation to determine which frame index +/// references it should create new base registers for. +bool ARMBaseRegisterInfo:: +needsFrameBaseReg(MachineInstr *MI, int64_t Offset) const { + for (unsigned i = 0; !MI->getOperand(i).isFI(); ++i) { + assert(i < MI->getNumOperands() &&"Instr doesn't have FrameIndex operand!"); + } + + // It's the load/store FI references that cause issues, as it can be difficult + // to materialize the offset if it won't fit in the literal field. Estimate + // based on the size of the local frame and some conservative assumptions + // about the rest of the stack frame (note, this is pre-regalloc, so + // we don't know everything for certain yet) whether this offset is likely + // to be out of range of the immediate. Return true if so. + + // We only generate virtual base registers for loads and stores, so + // return false for everything else. + unsigned Opc = MI->getOpcode(); + switch (Opc) { + case ARM::LDRi12: case ARM::LDRH: case ARM::LDRBi12: + case ARM::STRi12: case ARM::STRH: case ARM::STRBi12: + case ARM::t2LDRi12: case ARM::t2LDRi8: + case ARM::t2STRi12: case ARM::t2STRi8: + case ARM::VLDRS: case ARM::VLDRD: + case ARM::VSTRS: case ARM::VSTRD: + case ARM::tSTRspi: case ARM::tLDRspi: + if (ForceAllBaseRegAlloc) + return true; + break; + default: + return false; + } + + // Without a virtual base register, if the function has variable sized + // objects, all fixed-size local references will be via the frame pointer, + // Approximate the offset and see if it's legal for the instruction. + // Note that the incoming offset is based on the SP value at function entry, + // so it'll be negative. + MachineFunction &MF = *MI->getParent()->getParent(); + const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering(); + MachineFrameInfo *MFI = MF.getFrameInfo(); + ARMFunctionInfo *AFI = MF.getInfo(); + + // Estimate an offset from the frame pointer. + // Conservatively assume all callee-saved registers get pushed. R4-R6 + // will be earlier than the FP, so we ignore those. + // R7, LR + int64_t FPOffset = Offset - 8; + // ARM and Thumb2 functions also need to consider R8-R11 and D8-D15 + if (!AFI->isThumbFunction() || !AFI->isThumb1OnlyFunction()) + FPOffset -= 80; + // Estimate an offset from the stack pointer. + // The incoming offset is relating to the SP at the start of the function, + // but when we access the local it'll be relative to the SP after local + // allocation, so adjust our SP-relative offset by that allocation size. + Offset = -Offset; + Offset += MFI->getLocalFrameSize(); + // Assume that we'll have at least some spill slots allocated. + // FIXME: This is a total SWAG number. We should run some statistics + // and pick a real one. + Offset += 128; // 128 bytes of spill slots + + // If there is a frame pointer, try using it. + // The FP is only available if there is no dynamic realignment. We + // don't know for sure yet whether we'll need that, so we guess based + // on whether there are any local variables that would trigger it. + unsigned StackAlign = TFI->getStackAlignment(); + if (TFI->hasFP(MF) && + !((MFI->getLocalFrameMaxAlign() > StackAlign) && canRealignStack(MF))) { + if (isFrameOffsetLegal(MI, FPOffset)) + return false; + } + // If we can reference via the stack pointer, try that. + // FIXME: This (and the code that resolves the references) can be improved + // to only disallow SP relative references in the live range of + // the VLA(s). In practice, it's unclear how much difference that + // would make, but it may be worth doing. + if (!MFI->hasVarSizedObjects() && isFrameOffsetLegal(MI, Offset)) + return false; + + // The offset likely isn't legal, we want to allocate a virtual base register. + return true; +} + +/// materializeFrameBaseRegister - Insert defining instruction(s) for BaseReg to +/// be a pointer to FrameIdx at the beginning of the basic block. +void ARMBaseRegisterInfo:: +materializeFrameBaseRegister(MachineBasicBlock *MBB, + unsigned BaseReg, int FrameIdx, + int64_t Offset) const { + ARMFunctionInfo *AFI = MBB->getParent()->getInfo(); + unsigned ADDriOpc = !AFI->isThumbFunction() ? ARM::ADDri : + (AFI->isThumb1OnlyFunction() ? ARM::tADDrSPi : ARM::t2ADDri); + + MachineBasicBlock::iterator Ins = MBB->begin(); + DebugLoc DL; // Defaults to "unknown" + if (Ins != MBB->end()) + DL = Ins->getDebugLoc(); + + const MCInstrDesc &MCID = TII.get(ADDriOpc); + MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo(); + const MachineFunction &MF = *MBB->getParent(); + MRI.constrainRegClass(BaseReg, TII.getRegClass(MCID, 0, this, MF)); + + MachineInstrBuilder MIB = AddDefaultPred(BuildMI(*MBB, Ins, DL, MCID, BaseReg) + .addFrameIndex(FrameIdx).addImm(Offset)); + + if (!AFI->isThumb1OnlyFunction()) + AddDefaultCC(MIB); +} + +void +ARMBaseRegisterInfo::resolveFrameIndex(MachineBasicBlock::iterator I, + unsigned BaseReg, int64_t Offset) const { + MachineInstr &MI = *I; + MachineBasicBlock &MBB = *MI.getParent(); + MachineFunction &MF = *MBB.getParent(); + ARMFunctionInfo *AFI = MF.getInfo(); + int Off = Offset; // ARM doesn't need the general 64-bit offsets + unsigned i = 0; + + assert(!AFI->isThumb1OnlyFunction() && + "This resolveFrameIndex does not support Thumb1!"); + + while (!MI.getOperand(i).isFI()) { + ++i; + assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!"); + } + bool Done = false; + if (!AFI->isThumbFunction()) + Done = rewriteARMFrameIndex(MI, i, BaseReg, Off, TII); + else { + assert(AFI->isThumb2Function()); + Done = rewriteT2FrameIndex(MI, i, BaseReg, Off, TII); + } + assert (Done && "Unable to resolve frame index!"); + (void)Done; +} + +bool ARMBaseRegisterInfo::isFrameOffsetLegal(const MachineInstr *MI, + int64_t Offset) const { + const MCInstrDesc &Desc = MI->getDesc(); + unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask); + unsigned i = 0; + + while (!MI->getOperand(i).isFI()) { + ++i; + assert(i < MI->getNumOperands() &&"Instr doesn't have FrameIndex operand!"); + } + + // AddrMode4 and AddrMode6 cannot handle any offset. + if (AddrMode == ARMII::AddrMode4 || AddrMode == ARMII::AddrMode6) + return Offset == 0; + + unsigned NumBits = 0; + unsigned Scale = 1; + bool isSigned = true; + switch (AddrMode) { + case ARMII::AddrModeT2_i8: + case ARMII::AddrModeT2_i12: + // i8 supports only negative, and i12 supports only positive, so + // based on Offset sign, consider the appropriate instruction + Scale = 1; + if (Offset < 0) { + NumBits = 8; + Offset = -Offset; + } else { + NumBits = 12; + } + break; + case ARMII::AddrMode5: + // VFP address mode. + NumBits = 8; + Scale = 4; + break; + case ARMII::AddrMode_i12: + case ARMII::AddrMode2: + NumBits = 12; + break; + case ARMII::AddrMode3: + NumBits = 8; + break; + case ARMII::AddrModeT1_s: + NumBits = 5; + Scale = 4; + isSigned = false; + break; + default: + llvm_unreachable("Unsupported addressing mode!"); + } + + Offset += getFrameIndexInstrOffset(MI, i); + // Make sure the offset is encodable for instructions that scale the + // immediate. + if ((Offset & (Scale-1)) != 0) + return false; + + if (isSigned && Offset < 0) + Offset = -Offset; + + unsigned Mask = (1 << NumBits) - 1; + if ((unsigned)Offset <= Mask * Scale) + return true; + + return false; +} + +void ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, - int SPAdj, int *Value, - RegScavenger *RS) const { + int SPAdj, RegScavenger *RS) const { unsigned i = 0; MachineInstr &MI = *II; MachineBasicBlock &MBB = *MI.getParent(); MachineFunction &MF = *MBB.getParent(); + const ARMFrameLowering *TFI = + static_cast(MF.getTarget().getFrameLowering()); ARMFunctionInfo *AFI = MF.getInfo(); assert(!AFI->isThumb1OnlyFunction() && "This eliminateFrameIndex does not support Thumb1!"); @@ -1171,10 +753,29 @@ ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, int FrameIndex = MI.getOperand(i).getIndex(); unsigned FrameReg; - int Offset = getFrameIndexReference(MF, FrameIndex, FrameReg); - if (FrameReg != ARM::SP) - SPAdj = 0; - Offset += SPAdj; + int Offset = TFI->ResolveFrameIndexReference(MF, FrameIndex, FrameReg, SPAdj); + + // PEI::scavengeFrameVirtualRegs() cannot accurately track SPAdj because the + // call frame setup/destroy instructions have already been eliminated. That + // means the stack pointer cannot be used to access the emergency spill slot + // when !hasReservedCallFrame(). +#ifndef NDEBUG + if (RS && FrameReg == ARM::SP && FrameIndex == RS->getScavengingFrameIndex()){ + assert(TFI->hasReservedCallFrame(MF) && + "Cannot use SP to access the emergency spill slot in " + "functions without a reserved call frame"); + assert(!MF.getFrameInfo()->hasVarSizedObjects() && + "Cannot use SP to access the emergency spill slot in " + "functions with variable sized frame objects"); + } +#endif // NDEBUG + + // Special handling of dbg_value instructions. + if (MI.isDebugValue()) { + MI.getOperand(i). ChangeToRegister(FrameReg, false /*isDef*/); + MI.getOperand(i+1).ChangeToImmediate(Offset); + return; + } // Modify MI as necessary to handle as much of 'Offset' as possible bool Done = false; @@ -1185,7 +786,7 @@ ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, Done = rewriteT2FrameIndex(MI, i, FrameReg, Offset, TII); } if (Done) - return 0; + return; // 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 @@ -1204,8 +805,7 @@ ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, // Must be addrmode4/6. MI.getOperand(i).ChangeToRegister(FrameReg, false, false, false); else { - ScratchReg = MF.getRegInfo().createVirtualRegister(ARM::GPRRegisterClass); - if (Value) *Value = Offset; + ScratchReg = MF.getRegInfo().createVirtualRegister(&ARM::GPRRegClass); if (!AFI->isThumbFunction()) emitARMRegPlusImmediate(MBB, II, MI.getDebugLoc(), ScratchReg, FrameReg, Offset, Pred, PredReg, TII); @@ -1214,290 +814,7 @@ ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, emitT2RegPlusImmediate(MBB, II, MI.getDebugLoc(), ScratchReg, FrameReg, Offset, Pred, PredReg, TII); } + // Update the original instruction to use the scratch register. MI.getOperand(i).ChangeToRegister(ScratchReg, false, false, true); - if (!ReuseFrameIndexVals) - ScratchReg = 0; - } - return ScratchReg; -} - -/// Move iterator past 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 Opc1, int Opc2, unsigned Area, - const ARMSubtarget &STI) { - while (MBBI != MBB.end() && - ((MBBI->getOpcode() == Opc1) || (MBBI->getOpcode() == Opc2)) && - MBBI->getOperand(1).isFI()) { - 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 ARMBaseRegisterInfo:: -emitPrologue(MachineFunction &MF) const { - MachineBasicBlock &MBB = MF.front(); - MachineBasicBlock::iterator MBBI = MBB.begin(); - MachineFrameInfo *MFI = MF.getFrameInfo(); - ARMFunctionInfo *AFI = MF.getInfo(); - assert(!AFI->isThumb1OnlyFunction() && - "This emitPrologue does not support Thumb1!"); - bool isARM = !AFI->isThumbFunction(); - unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize(); - unsigned NumBytes = MFI->getStackSize(); - const std::vector &CSI = MFI->getCalleeSavedInfo(); - DebugLoc dl = (MBBI != MBB.end() ? - MBBI->getDebugLoc() : DebugLoc::getUnknownLoc()); - - // 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; - - // Allocate the vararg register save area. This is not counted in NumBytes. - if (VARegSaveSize) - emitSPUpdate(isARM, MBB, MBBI, dl, TII, -VARegSaveSize); - - if (!AFI->hasStackFrame()) { - if (NumBytes != 0) - emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes); - 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; - } - } - - // Build the new SUBri to adjust SP for integer callee-save spill area 1. - emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS1Size); - movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, ARM::t2STRi12, 1, STI); - - // Set FP to point to the stack slot that contains the previous FP. - // For Darwin, FP is R7, which has now been stored in spill area 1. - // Otherwise, if this is not Darwin, all the callee-saved registers go - // into spill area 1, including the FP in R11. In either case, it is - // now safe to emit this assignment. - if (STI.isTargetDarwin() || hasFP(MF)) { - unsigned ADDriOpc = !AFI->isThumbFunction() ? ARM::ADDri : ARM::t2ADDri; - MachineInstrBuilder MIB = - BuildMI(MBB, MBBI, dl, TII.get(ADDriOpc), FramePtr) - .addFrameIndex(FramePtrSpillFI).addImm(0); - AddDefaultCC(AddDefaultPred(MIB)); - } - - // Build the new SUBri to adjust SP for integer callee-save spill area 2. - emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS2Size); - - // Build the new SUBri to adjust SP for FP callee-save spill area. - movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, ARM::t2STRi12, 2, STI); - emitSPUpdate(isARM, MBB, MBBI, dl, TII, -DPRCSSize); - - // 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); - - movePastCSLoadStoreOps(MBB, MBBI, ARM::VSTRD, 0, 3, STI); - NumBytes = DPRCSOffset; - if (NumBytes) { - // Adjust SP after all the callee-save spills. - emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes); - } - - if (STI.isTargetELF() && hasFP(MF)) { - MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() - - AFI->getFramePtrSpillOffset()); - } - - AFI->setGPRCalleeSavedArea1Size(GPRCS1Size); - AFI->setGPRCalleeSavedArea2Size(GPRCS2Size); - AFI->setDPRCalleeSavedAreaSize(DPRCSSize); - - // If we need dynamic stack realignment, do it here. - if (needsStackRealignment(MF)) { - unsigned MaxAlign = MFI->getMaxAlignment(); - assert (!AFI->isThumb1OnlyFunction()); - if (!AFI->isThumbFunction()) { - // Emit bic sp, sp, MaxAlign - AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl, - TII.get(ARM::BICri), ARM::SP) - .addReg(ARM::SP, RegState::Kill) - .addImm(MaxAlign-1))); - } else { - // We cannot use sp as source/dest register here, thus we're emitting the - // following sequence: - // mov r4, sp - // bic r4, r4, MaxAlign - // mov sp, r4 - // FIXME: It will be better just to find spare register here. - BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2tgpr), ARM::R4) - .addReg(ARM::SP, RegState::Kill); - AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl, - TII.get(ARM::t2BICri), ARM::R4) - .addReg(ARM::R4, RegState::Kill) - .addImm(MaxAlign-1))); - BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVtgpr2gpr), ARM::SP) - .addReg(ARM::R4, RegState::Kill); - } } } - -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 ARMBaseInstrInfo &TII, - const unsigned *CSRegs) { - return ((MI->getOpcode() == (int)ARM::VLDRD || - MI->getOpcode() == (int)ARM::LDR || - MI->getOpcode() == (int)ARM::t2LDRi12) && - MI->getOperand(1).isFI() && - isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs)); -} - -void ARMBaseRegisterInfo:: -emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const { - MachineBasicBlock::iterator MBBI = prior(MBB.end()); - assert(MBBI->getDesc().isReturn() && - "Can only insert epilog into returning blocks"); - DebugLoc dl = MBBI->getDebugLoc(); - MachineFrameInfo *MFI = MF.getFrameInfo(); - ARMFunctionInfo *AFI = MF.getInfo(); - assert(!AFI->isThumb1OnlyFunction() && - "This emitEpilogue does not support Thumb1!"); - bool isARM = !AFI->isThumbFunction(); - - unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize(); - int NumBytes = (int)MFI->getStackSize(); - - if (!AFI->hasStackFrame()) { - if (NumBytes != 0) - emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes); - } else { - // Unwind MBBI to point to first LDR / VLDRD. - const unsigned *CSRegs = getCalleeSavedRegs(); - if (MBBI != MBB.begin()) { - do - --MBBI; - while (MBBI != MBB.begin() && isCSRestore(MBBI, TII, CSRegs)); - if (!isCSRestore(MBBI, TII, CSRegs)) - ++MBBI; - } - - // Move SP to start of FP callee save spill area. - NumBytes -= (AFI->getGPRCalleeSavedArea1Size() + - AFI->getGPRCalleeSavedArea2Size() + - AFI->getDPRCalleeSavedAreaSize()); - - // Darwin ABI requires FP to point to the stack slot that contains the - // previous FP. - bool HasFP = hasFP(MF); - if ((STI.isTargetDarwin() && NumBytes) || HasFP) { - 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 (HasFP || - AFI->getGPRCalleeSavedArea2Size() || - AFI->getDPRCalleeSavedAreaSize() || - AFI->getDPRCalleeSavedAreaOffset()) { - if (NumBytes) { - if (isARM) - emitARMRegPlusImmediate(MBB, MBBI, dl, ARM::SP, FramePtr, -NumBytes, - ARMCC::AL, 0, TII); - else - emitT2RegPlusImmediate(MBB, MBBI, dl, ARM::SP, FramePtr, -NumBytes, - ARMCC::AL, 0, TII); - } else { - // Thumb2 or ARM. - if (isARM) - BuildMI(MBB, MBBI, dl, TII.get(ARM::MOVr), ARM::SP) - .addReg(FramePtr) - .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0); - else - BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2gpr), ARM::SP) - .addReg(FramePtr); - } - } - } else if (NumBytes) - emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes); - - // Move SP to start of integer callee save spill area 2. - movePastCSLoadStoreOps(MBB, MBBI, ARM::VLDRD, 0, 3, STI); - emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getDPRCalleeSavedAreaSize()); - - // Move SP to start of integer callee save spill area 1. - movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, ARM::t2LDRi12, 2, STI); - emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea2Size()); - - // Move SP to SP upon entry to the function. - movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, ARM::t2LDRi12, 1, STI); - emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea1Size()); - } - - if (VARegSaveSize) - emitSPUpdate(isARM, MBB, MBBI, dl, TII, VARegSaveSize); -} - -#include "ARMGenRegisterInfo.inc"