X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTarget%2FARM%2FThumb1RegisterInfo.cpp;h=6197d4fd1bea1a1700d1b70b2d6d6a1fb62fd60c;hb=09aa3f0ef35d9241c92439d74b8d5e9a81d814c2;hp=b723c853eff06e670962c0412f346fa3a0484d20;hpb=f6fe9579505be86420beea04f2c9ecb0fd7c55fd;p=oota-llvm.git diff --git a/lib/Target/ARM/Thumb1RegisterInfo.cpp b/lib/Target/ARM/Thumb1RegisterInfo.cpp index b723c853eff..6197d4fd1be 100644 --- a/lib/Target/ARM/Thumb1RegisterInfo.cpp +++ b/lib/Target/ARM/Thumb1RegisterInfo.cpp @@ -1,4 +1,4 @@ -//===- Thumb1RegisterInfo.cpp - Thumb-1 Register Information -------*- C++ -*-===// +//===- Thumb1RegisterInfo.cpp - Thumb-1 Register Information ----*- C++ -*-===// // // The LLVM Compiler Infrastructure // @@ -7,7 +7,8 @@ // //===----------------------------------------------------------------------===// // -// This file contains the Thumb-1 implementation of the TargetRegisterInfo class. +// This file contains the Thumb-1 implementation of the TargetRegisterInfo +// class. // //===----------------------------------------------------------------------===// @@ -35,12 +36,12 @@ #include "llvm/Support/CommandLine.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" -using namespace llvm; -static cl::opt -ThumbRegScavenging("enable-thumb-reg-scavenging", - cl::Hidden, - cl::desc("Enable register scavenging on Thumb")); +namespace llvm { +extern cl::opt ReuseFrameIndexVals; +} + +using namespace llvm; Thumb1RegisterInfo::Thumb1RegisterInfo(const ARMBaseInstrInfo &tii, const ARMSubtarget &sti) @@ -58,8 +59,8 @@ void Thumb1RegisterInfo::emitLoadConstPool(MachineBasicBlock &MBB, unsigned PredReg) const { MachineFunction &MF = *MBB.getParent(); MachineConstantPool *ConstantPool = MF.getConstantPool(); - Constant *C = - MF.getFunction()->getContext()->getConstantInt(Type::Int32Ty, Val); + const Constant *C = ConstantInt::get( + Type::getInt32Ty(MBB.getParent()->getFunction()->getContext()), Val); unsigned Idx = ConstantPool->getConstantPoolIndex(C, 4); BuildMI(MBB, MBBI, dl, TII.get(ARM::tLDRcp)) @@ -67,39 +68,6 @@ void Thumb1RegisterInfo::emitLoadConstPool(MachineBasicBlock &MBB, .addConstantPoolIndex(Idx).addImm(Pred).addReg(PredReg); } -const TargetRegisterClass* -Thumb1RegisterInfo::getPhysicalRegisterRegClass(unsigned Reg, MVT VT) const { - if (isARMLowRegister(Reg)) - return ARM::tGPRRegisterClass; - switch (Reg) { - default: - break; - case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11: - case ARM::R12: case ARM::SP: case ARM::LR: case ARM::PC: - return ARM::GPRRegisterClass; - } - - return TargetRegisterInfo::getPhysicalRegisterRegClass(Reg, VT); -} - -bool -Thumb1RegisterInfo::requiresRegisterScavenging(const MachineFunction &MF) const { - return ThumbRegScavenging; -} - -bool Thumb1RegisterInfo::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 << 8) - 1) * 4 / 2) // Half of imm8 * 4 - return false; - - return !MF.getFrameInfo()->hasVarSizedObjects(); -} - /// emitThumbRegPlusImmInReg - Emits a series of instructions to materialize /// a destreg = basereg + immediate in Thumb code. Materialize the immediate @@ -111,8 +79,9 @@ void emitThumbRegPlusImmInReg(MachineBasicBlock &MBB, unsigned DestReg, unsigned BaseReg, int NumBytes, bool CanChangeCC, const TargetInstrInfo &TII, - const Thumb1RegisterInfo& MRI, + const ARMBaseRegisterInfo& MRI, DebugLoc dl) { + MachineFunction &MF = *MBB.getParent(); bool isHigh = !isARMLowRegister(DestReg) || (BaseReg != 0 && !isARMLowRegister(BaseReg)); bool isSub = false; @@ -127,9 +96,7 @@ void emitThumbRegPlusImmInReg(MachineBasicBlock &MBB, unsigned LdReg = DestReg; if (DestReg == ARM::SP) { assert(BaseReg == ARM::SP && "Unexpected!"); - LdReg = ARM::R3; - BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVlor2hir), ARM::R12) - .addReg(ARM::R3, RegState::Kill); + LdReg = MF.getRegInfo().createVirtualRegister(ARM::tGPRRegisterClass); } if (NumBytes <= 255 && NumBytes >= 0) @@ -154,10 +121,6 @@ void emitThumbRegPlusImmInReg(MachineBasicBlock &MBB, else MIB.addReg(LdReg).addReg(BaseReg, RegState::Kill); AddDefaultPred(MIB); - - if (DestReg == ARM::SP) - BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVhir2lor), ARM::R3) - .addReg(ARM::R12, RegState::Kill); } /// calcNumMI - Returns the number of instructions required to materialize @@ -186,13 +149,12 @@ static unsigned calcNumMI(int Opc, int ExtraOpc, unsigned Bytes, /// 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, - const Thumb1RegisterInfo& MRI, - DebugLoc dl) { +void llvm::emitThumbRegPlusImmediate(MachineBasicBlock &MBB, + MachineBasicBlock::iterator &MBBI, + unsigned DestReg, unsigned BaseReg, + int NumBytes, const TargetInstrInfo &TII, + const ARMBaseRegisterInfo& MRI, + DebugLoc dl) { bool isSub = NumBytes < 0; unsigned Bytes = (unsigned)NumBytes; if (isSub) Bytes = -NumBytes; @@ -328,7 +290,9 @@ static void emitSPUpdate(MachineBasicBlock &MBB, void Thumb1RegisterInfo:: eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, MachineBasicBlock::iterator I) const { - if (!hasReservedCallFrame(MF)) { + const TargetFrameInfo *TFI = MF.getTarget().getFrameInfo(); + + if (!TFI->hasReservedCallFrame(MF)) { // If we have alloca, convert as follows: // ADJCALLSTACKDOWN -> sub, sp, sp, amount // ADJCALLSTACKUP -> add, sp, sp, amount @@ -387,43 +351,19 @@ static void removeOperands(MachineInstr &MI, unsigned i) { MI.RemoveOperand(Op); } -void Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, - int SPAdj, RegScavenger *RS) const{ - unsigned i = 0; +bool Thumb1RegisterInfo:: +rewriteFrameIndex(MachineBasicBlock::iterator II, unsigned FrameRegIdx, + unsigned FrameReg, int &Offset, + const ARMBaseInstrInfo &TII) const { MachineInstr &MI = *II; MachineBasicBlock &MBB = *MI.getParent(); - MachineFunction &MF = *MBB.getParent(); - ARMFunctionInfo *AFI = MF.getInfo(); DebugLoc dl = MI.getDebugLoc(); - - while (!MI.getOperand(i).isFI()) { - ++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 (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 TargetInstrDesc &Desc = MI.getDesc(); unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask); if (Opcode == ARM::tADDrSPi) { - Offset += MI.getOperand(i+1).getImm(); + Offset += MI.getOperand(FrameRegIdx+1).getImm(); // Can't use tADDrSPi if it's based off the frame pointer. unsigned NumBits = 0; @@ -439,12 +379,17 @@ void Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, "Thumb add/sub sp, #imm immediate must be multiple of 4!"); } - if (Offset == 0) { + unsigned PredReg; + if (Offset == 0 && getInstrPredicate(&MI, PredReg) == ARMCC::AL) { // Turn it into a move. - MI.setDesc(TII.get(ARM::tMOVhir2lor)); - MI.getOperand(i).ChangeToRegister(FrameReg, false); - MI.RemoveOperand(i+1); - return; + MI.setDesc(TII.get(ARM::tMOVgpr2tgpr)); + MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false); + // Remove offset and remaining explicit predicate operands. + do MI.RemoveOperand(FrameRegIdx+1); + while (MI.getNumOperands() > FrameRegIdx+1 && + (!MI.getOperand(FrameRegIdx+1).isReg() || + !MI.getOperand(FrameRegIdx+1).isImm())); + return true; } // Common case: small offset, fits into instruction. @@ -452,15 +397,15 @@ void Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, if (((Offset / Scale) & ~Mask) == 0) { // Replace the FrameIndex with sp / fp if (Opcode == ARM::tADDi3) { - removeOperands(MI, i); + removeOperands(MI, FrameRegIdx); MachineInstrBuilder MIB(&MI); AddDefaultPred(AddDefaultT1CC(MIB).addReg(FrameReg) .addImm(Offset / Scale)); } else { - MI.getOperand(i).ChangeToRegister(FrameReg, false); - MI.getOperand(i+1).ChangeToImmediate(Offset / Scale); + MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false); + MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset / Scale); } - return; + return true; } unsigned DestReg = MI.getOperand(0).getReg(); @@ -472,7 +417,7 @@ void Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, emitThumbRegPlusImmediate(MBB, II, DestReg, FrameReg, Offset, TII, *this, dl); MBB.erase(II); - return; + return true; } if (Offset > 0) { @@ -480,15 +425,15 @@ void Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, // r0 = add sp, 255*4 // r0 = add r0, (imm - 255*4) if (Opcode == ARM::tADDi3) { - removeOperands(MI, i); + removeOperands(MI, FrameRegIdx); MachineInstrBuilder MIB(&MI); AddDefaultPred(AddDefaultT1CC(MIB).addReg(FrameReg).addImm(Mask)); } else { - MI.getOperand(i).ChangeToRegister(FrameReg, false); - MI.getOperand(i+1).ChangeToImmediate(Mask); + MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false); + MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Mask); } Offset = (Offset - Mask * Scale); - MachineBasicBlock::iterator NII = next(II); + MachineBasicBlock::iterator NII = llvm::next(II); emitThumbRegPlusImmediate(MBB, NII, DestReg, DestReg, Offset, TII, *this, dl); } else { @@ -496,11 +441,16 @@ void Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, // r0 = -imm (this is then translated into a series of instructons) // r0 = add r0, sp emitThumbConstant(MBB, II, DestReg, Offset, TII, *this, dl); + MI.setDesc(TII.get(ARM::tADDhirr)); - MI.getOperand(i).ChangeToRegister(DestReg, false, false, true); - MI.getOperand(i+1).ChangeToRegister(FrameReg, false); + MI.getOperand(FrameRegIdx).ChangeToRegister(DestReg, false, false, true); + MI.getOperand(FrameRegIdx+1).ChangeToRegister(FrameReg, false); + if (Opcode == ARM::tADDi3) { + MachineInstrBuilder MIB(&MI); + AddDefaultPred(MIB); + } } - return; + return true; } else { unsigned ImmIdx = 0; int InstrOffs = 0; @@ -508,7 +458,7 @@ void Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, unsigned Scale = 1; switch (AddrMode) { case ARMII::AddrModeT1_s: { - ImmIdx = i+1; + ImmIdx = FrameRegIdx+1; InstrOffs = MI.getOperand(ImmIdx).getImm(); NumBits = (FrameReg == ARM::SP) ? 8 : 5; Scale = 4; @@ -528,9 +478,9 @@ void Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, unsigned Mask = (1 << NumBits) - 1; if ((unsigned)Offset <= Mask * Scale) { // Replace the FrameIndex with sp - MI.getOperand(i).ChangeToRegister(FrameReg, false); + MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false); ImmOp.ChangeToImmediate(ImmedOffset); - return; + return true; } bool isThumSpillRestore = Opcode == ARM::tRestore || Opcode == ARM::tSpill; @@ -551,12 +501,127 @@ void Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, Offset &= ~(Mask*Scale); } } + return Offset == 0; +} + +void +Thumb1RegisterInfo::resolveFrameIndex(MachineBasicBlock::iterator I, + unsigned BaseReg, int64_t Offset) const { + MachineInstr &MI = *I; + int Off = Offset; // ARM doesn't need the general 64-bit offsets + unsigned i = 0; + + while (!MI.getOperand(i).isFI()) { + ++i; + assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!"); + } + bool Done = false; + Done = rewriteFrameIndex(MI, i, BaseReg, Off, TII); + assert (Done && "Unable to resolve frame index!"); +} + +/// saveScavengerRegister - Spill the register so it can be used by the +/// register scavenger. Return true. +bool +Thumb1RegisterInfo::saveScavengerRegister(MachineBasicBlock &MBB, + MachineBasicBlock::iterator I, + MachineBasicBlock::iterator &UseMI, + const TargetRegisterClass *RC, + unsigned Reg) const { + // Thumb1 can't use the emergency spill slot on the stack because + // ldr/str immediate offsets must be positive, and if we're referencing + // off the frame pointer (if, for example, there are alloca() calls in + // the function, the offset will be negative. Use R12 instead since that's + // a call clobbered register that we know won't be used in Thumb1 mode. + DebugLoc DL; + BuildMI(MBB, I, DL, TII.get(ARM::tMOVtgpr2gpr)). + addReg(ARM::R12, RegState::Define).addReg(Reg, RegState::Kill); + + // The UseMI is where we would like to restore the register. If there's + // interference with R12 before then, however, we'll need to restore it + // before that instead and adjust the UseMI. + bool done = false; + for (MachineBasicBlock::iterator II = I; !done && II != UseMI ; ++II) { + if (II->isDebugValue()) + continue; + // If this instruction affects R12, adjust our restore point. + for (unsigned i = 0, e = II->getNumOperands(); i != e; ++i) { + const MachineOperand &MO = II->getOperand(i); + if (!MO.isReg() || MO.isUndef() || !MO.getReg() || + TargetRegisterInfo::isVirtualRegister(MO.getReg())) + continue; + if (MO.getReg() == ARM::R12) { + UseMI = II; + done = true; + break; + } + } + } + // Restore the register from R12 + BuildMI(MBB, UseMI, DL, TII.get(ARM::tMOVgpr2tgpr)). + addReg(Reg, RegState::Define).addReg(ARM::R12, RegState::Kill); + + return true; +} + +void +Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, + int SPAdj, RegScavenger *RS) const { + unsigned VReg = 0; + unsigned i = 0; + MachineInstr &MI = *II; + MachineBasicBlock &MBB = *MI.getParent(); + MachineFunction &MF = *MBB.getParent(); + ARMFunctionInfo *AFI = MF.getInfo(); + DebugLoc dl = MI.getDebugLoc(); + + while (!MI.getOperand(i).isFI()) { + ++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 (MF.getFrameInfo()->hasVarSizedObjects()) { + assert(SPAdj == 0 && MF.getTarget().getFrameInfo()->hasFP(MF) && + "Unexpected"); + // There are alloca()'s in this function, must reference off the frame + // pointer or base pointer instead. + if (!hasBasePointer(MF)) { + FrameReg = getFrameRegister(MF); + Offset -= AFI->getFramePtrSpillOffset(); + } else + FrameReg = BasePtr; + } + + // 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 + assert(AFI->isThumbFunction() && + "This eliminateFrameIndex only supports Thumb1!"); + if (rewriteFrameIndex(MI, i, FrameReg, Offset, TII)) + 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 // SP+LargeImm. assert(Offset && "This code isn't needed if offset already handled!"); + unsigned Opcode = MI.getOpcode(); + const TargetInstrDesc &Desc = MI.getDesc(); + // Remove predicate first. int PIdx = MI.findFirstPredOperandIdx(); if (PIdx != -1) @@ -587,50 +652,26 @@ void Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, else // tLDR has an extra register operand. MI.addOperand(MachineOperand::CreateReg(0, false)); } else if (Desc.mayStore()) { - // 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, dl, TII.get(ARM::tMOVlor2hir), ARM::R12) - .addReg(ARM::R2, RegState::Kill); - TmpReg = ARM::R2; - } - if (TmpReg == ARM::R3 && AFI->isR3LiveIn()) - BuildMI(MBB, II, dl, TII.get(ARM::tMOVlor2hir), ARM::R12) - .addReg(ARM::R3, RegState::Kill); - if (Opcode == ARM::tSpill) { - if (FrameReg == ARM::SP) - emitThumbRegPlusImmInReg(MBB, II, TmpReg, FrameReg, - Offset, false, TII, *this, dl); - else { - emitLoadConstPool(MBB, II, dl, TmpReg, 0, Offset); - UseRR = true; - } - } else - emitThumbRegPlusImmediate(MBB, II, TmpReg, FrameReg, Offset, TII, - *this, dl); - MI.setDesc(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, dl, TII.get(ARM::tMOVhir2lor), ARM::R2) - .addReg(ARM::R12, RegState::Kill); - if (TmpReg == ARM::R3 && AFI->isR3LiveIn()) - BuildMI(MBB, NII, dl, TII.get(ARM::tMOVhir2lor), ARM::R3) - .addReg(ARM::R12, RegState::Kill); + VReg = MF.getRegInfo().createVirtualRegister(ARM::tGPRRegisterClass); + bool UseRR = false; + + if (Opcode == ARM::tSpill) { + if (FrameReg == ARM::SP) + emitThumbRegPlusImmInReg(MBB, II, VReg, FrameReg, + Offset, false, TII, *this, dl); + else { + emitLoadConstPool(MBB, II, dl, VReg, 0, Offset); + UseRR = true; + } + } else + emitThumbRegPlusImmediate(MBB, II, VReg, FrameReg, Offset, TII, + *this, dl); + MI.setDesc(TII.get(ARM::tSTR)); + MI.getOperand(i).ChangeToRegister(VReg, 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)); } else assert(false && "Unexpected opcode!"); @@ -640,191 +681,3 @@ void Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, AddDefaultPred(MIB); } } - -void Thumb1RegisterInfo::emitPrologue(MachineFunction &MF) const { - MachineBasicBlock &MBB = MF.front(); - MachineBasicBlock::iterator MBBI = MBB.begin(); - MachineFrameInfo *MFI = MF.getFrameInfo(); - ARMFunctionInfo *AFI = MF.getInfo(); - unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize(); - unsigned NumBytes = MFI->getStackSize(); - const std::vector &CSI = MFI->getCalleeSavedInfo(); - DebugLoc dl = (MBBI != MBB.end() ? - MBBI->getDebugLoc() : DebugLoc::getUnknownLoc()); - - // 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, TII, dl, *this, -VARegSaveSize); - - if (!AFI->hasStackFrame()) { - if (NumBytes != 0) - emitSPUpdate(MBB, MBBI, TII, dl, *this, -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; - } - } - - if (MBBI != MBB.end() && MBBI->getOpcode() == ARM::tPUSH) { - ++MBBI; - if (MBBI != MBB.end()) - dl = MBBI->getDebugLoc(); - } - - // 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, dl, TII.get(ARM::tADDrSPi), FramePtr) - .addFrameIndex(FramePtrSpillFI).addImm(0); - } - - // 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. - emitSPUpdate(MBB, MBBI, TII, dl, *this, -NumBytes); - } - - 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::tRestore && - MI->getOperand(1).isFI() && - isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs)); -} - -void Thumb1RegisterInfo::emitEpilogue(MachineFunction &MF, - MachineBasicBlock &MBB) const { - MachineBasicBlock::iterator MBBI = prior(MBB.end()); - assert((MBBI->getOpcode() == ARM::tBX_RET || - MBBI->getOpcode() == ARM::tPOP_RET) && - "Can only insert epilog into returning blocks"); - DebugLoc dl = MBBI->getDebugLoc(); - MachineFrameInfo *MFI = MF.getFrameInfo(); - ARMFunctionInfo *AFI = MF.getInfo(); - unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize(); - int NumBytes = (int)MFI->getStackSize(); - - if (!AFI->hasStackFrame()) { - if (NumBytes != 0) - emitSPUpdate(MBB, MBBI, TII, dl, *this, NumBytes); - } 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 (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, *this, dl); - else - BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVlor2hir), 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, TII, dl, *this, NumBytes); - } else - emitSPUpdate(MBB, MBBI, TII, dl, *this, NumBytes); - } - } - - if (VARegSaveSize) { - // 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, dl, TII.get(ARM::tPOP)).addReg(ARM::R3); - - emitSPUpdate(MBB, MBBI, TII, dl, *this, VARegSaveSize); - - BuildMI(MBB, MBBI, dl, TII.get(ARM::tBX_RET_vararg)).addReg(ARM::R3); - MBB.erase(MBBI); - } -}