//===- XCoreRegisterInfo.cpp - XCore Register Information -------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file contains the XCore implementation of the MRegisterInfo class. // //===----------------------------------------------------------------------===// #include "XCoreRegisterInfo.h" #include "XCoreMachineFunctionInfo.h" #include "XCore.h" #include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineFrameInfo.h" #include "llvm/CodeGen/MachineLocation.h" #include "llvm/CodeGen/MachineModuleInfo.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/Target/TargetInstrInfo.h" #include "llvm/Type.h" #include "llvm/Function.h" #include "llvm/ADT/BitVector.h" #include "llvm/ADT/STLExtras.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" using namespace llvm; XCoreRegisterInfo::XCoreRegisterInfo(const TargetInstrInfo &tii) : XCoreGenRegisterInfo(XCore::ADJCALLSTACKDOWN, XCore::ADJCALLSTACKUP), TII(tii) { } // helper functions static inline bool isImmUs(unsigned val) { return val <= 11; } static inline bool isImmU6(unsigned val) { return val < (1 << 6); } static inline bool isImmU16(unsigned val) { return val < (1 << 16); } static const unsigned XCore_ArgRegs[] = { XCore::R0, XCore::R1, XCore::R2, XCore::R3 }; const unsigned * XCoreRegisterInfo::getArgRegs(const MachineFunction *MF) { return XCore_ArgRegs; } unsigned XCoreRegisterInfo::getNumArgRegs(const MachineFunction *MF) { return array_lengthof(XCore_ArgRegs); } bool XCoreRegisterInfo::needsFrameMoves(const MachineFunction &MF) { const MachineFrameInfo *MFI = MF.getFrameInfo(); MachineModuleInfo *MMI = MFI->getMachineModuleInfo(); return (MMI && MMI->hasDebugInfo()) || !MF.getFunction()->doesNotThrow() || UnwindTablesMandatory; } const unsigned* XCoreRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const { static const unsigned CalleeSavedRegs[] = { XCore::R4, XCore::R5, XCore::R6, XCore::R7, XCore::R8, XCore::R9, XCore::R10, XCore::LR, 0 }; return CalleeSavedRegs; } const TargetRegisterClass* const* XCoreRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const { static const TargetRegisterClass * const CalleeSavedRegClasses[] = { XCore::GRRegsRegisterClass, XCore::GRRegsRegisterClass, XCore::GRRegsRegisterClass, XCore::GRRegsRegisterClass, XCore::GRRegsRegisterClass, XCore::GRRegsRegisterClass, XCore::GRRegsRegisterClass, XCore::RRegsRegisterClass, 0 }; return CalleeSavedRegClasses; } BitVector XCoreRegisterInfo::getReservedRegs(const MachineFunction &MF) const { BitVector Reserved(getNumRegs()); Reserved.set(XCore::CP); Reserved.set(XCore::DP); Reserved.set(XCore::SP); Reserved.set(XCore::LR); if (hasFP(MF)) { Reserved.set(XCore::R10); } return Reserved; } bool XCoreRegisterInfo::requiresRegisterScavenging(const MachineFunction &MF) const { // TODO can we estimate stack size? return hasFP(MF); } bool XCoreRegisterInfo::hasFP(const MachineFunction &MF) const { return NoFramePointerElim || MF.getFrameInfo()->hasVarSizedObjects(); } // This function eliminates ADJCALLSTACKDOWN, // ADJCALLSTACKUP pseudo instructions void XCoreRegisterInfo:: eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, MachineBasicBlock::iterator I) const { if (!hasReservedCallFrame(MF)) { // Turn the adjcallstackdown instruction into 'extsp ' and the // adjcallstackup instruction into 'ldaw sp, sp[]' MachineInstr *Old = I; uint64_t Amount = Old->getOperand(0).getImm(); if (Amount != 0) { // 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; assert(Amount%4 == 0); Amount /= 4; bool isU6 = isImmU6(Amount); if (!isU6 && !isImmU16(Amount)) { // FIX could emit multiple instructions in this case. #ifndef NDEBUG errs() << "eliminateCallFramePseudoInstr size too big: " << Amount << "\n"; #endif llvm_unreachable(0); } MachineInstr *New; if (Old->getOpcode() == XCore::ADJCALLSTACKDOWN) { int Opcode = isU6 ? XCore::EXTSP_u6 : XCore::EXTSP_lu6; New=BuildMI(MF, Old->getDebugLoc(), TII.get(Opcode)) .addImm(Amount); } else { assert(Old->getOpcode() == XCore::ADJCALLSTACKUP); int Opcode = isU6 ? XCore::LDAWSP_ru6_RRegs : XCore::LDAWSP_lru6_RRegs; New=BuildMI(MF, Old->getDebugLoc(), TII.get(Opcode), XCore::SP) .addImm(Amount); } // Replace the pseudo instruction with a new instruction... MBB.insert(I, New); } } MBB.erase(I); } unsigned XCoreRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj, int *Value, RegScavenger *RS) const { assert(SPAdj == 0 && "Unexpected"); MachineInstr &MI = *II; DebugLoc dl = MI.getDebugLoc(); unsigned i = 0; while (!MI.getOperand(i).isFI()) { ++i; assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!"); } MachineOperand &FrameOp = MI.getOperand(i); int FrameIndex = FrameOp.getIndex(); MachineFunction &MF = *MI.getParent()->getParent(); int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex); int StackSize = MF.getFrameInfo()->getStackSize(); #ifndef NDEBUG DEBUG(errs() << "\nFunction : " << MF.getFunction()->getName() << "\n"); DEBUG(errs() << "<--------->\n"); DEBUG(MI.print(errs())); DEBUG(errs() << "FrameIndex : " << FrameIndex << "\n"); DEBUG(errs() << "FrameOffset : " << Offset << "\n"); DEBUG(errs() << "StackSize : " << StackSize << "\n"); #endif Offset += StackSize; // fold constant into offset. Offset += MI.getOperand(i + 1).getImm(); MI.getOperand(i + 1).ChangeToImmediate(0); assert(Offset%4 == 0 && "Misaligned stack offset"); DEBUG(errs() << "Offset : " << Offset << "\n" << "<--------->\n"); Offset/=4; bool FP = hasFP(MF); unsigned Reg = MI.getOperand(0).getReg(); bool isKill = MI.getOpcode() == XCore::STWFI && MI.getOperand(0).isKill(); assert(XCore::GRRegsRegisterClass->contains(Reg) && "Unexpected register operand"); MachineBasicBlock &MBB = *MI.getParent(); if (FP) { bool isUs = isImmUs(Offset); unsigned FramePtr = XCore::R10; if (!isUs) { if (!RS) { std::string msg; raw_string_ostream Msg(msg); Msg << "eliminateFrameIndex Frame size too big: " << Offset; llvm_report_error(Msg.str()); } unsigned ScratchReg = RS->scavengeRegister(XCore::GRRegsRegisterClass, II, SPAdj); loadConstant(MBB, II, ScratchReg, Offset, dl); switch (MI.getOpcode()) { case XCore::LDWFI: BuildMI(MBB, II, dl, TII.get(XCore::LDW_3r), Reg) .addReg(FramePtr) .addReg(ScratchReg, RegState::Kill); break; case XCore::STWFI: BuildMI(MBB, II, dl, TII.get(XCore::STW_3r)) .addReg(Reg, getKillRegState(isKill)) .addReg(FramePtr) .addReg(ScratchReg, RegState::Kill); break; case XCore::LDAWFI: BuildMI(MBB, II, dl, TII.get(XCore::LDAWF_l3r), Reg) .addReg(FramePtr) .addReg(ScratchReg, RegState::Kill); break; default: llvm_unreachable("Unexpected Opcode"); } } else { switch (MI.getOpcode()) { case XCore::LDWFI: BuildMI(MBB, II, dl, TII.get(XCore::LDW_2rus), Reg) .addReg(FramePtr) .addImm(Offset); break; case XCore::STWFI: BuildMI(MBB, II, dl, TII.get(XCore::STW_2rus)) .addReg(Reg, getKillRegState(isKill)) .addReg(FramePtr) .addImm(Offset); break; case XCore::LDAWFI: BuildMI(MBB, II, dl, TII.get(XCore::LDAWF_l2rus), Reg) .addReg(FramePtr) .addImm(Offset); break; default: llvm_unreachable("Unexpected Opcode"); } } } else { bool isU6 = isImmU6(Offset); if (!isU6 && !isImmU16(Offset)) { std::string msg; raw_string_ostream Msg(msg); Msg << "eliminateFrameIndex Frame size too big: " << Offset; llvm_report_error(Msg.str()); } switch (MI.getOpcode()) { int NewOpcode; case XCore::LDWFI: NewOpcode = (isU6) ? XCore::LDWSP_ru6 : XCore::LDWSP_lru6; BuildMI(MBB, II, dl, TII.get(NewOpcode), Reg) .addImm(Offset); break; case XCore::STWFI: NewOpcode = (isU6) ? XCore::STWSP_ru6 : XCore::STWSP_lru6; BuildMI(MBB, II, dl, TII.get(NewOpcode)) .addReg(Reg, getKillRegState(isKill)) .addImm(Offset); break; case XCore::LDAWFI: NewOpcode = (isU6) ? XCore::LDAWSP_ru6 : XCore::LDAWSP_lru6; BuildMI(MBB, II, dl, TII.get(NewOpcode), Reg) .addImm(Offset); break; default: llvm_unreachable("Unexpected Opcode"); } } // Erase old instruction. MBB.erase(II); return 0; } void XCoreRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF, RegScavenger *RS) const { MachineFrameInfo *MFI = MF.getFrameInfo(); bool LRUsed = MF.getRegInfo().isPhysRegUsed(XCore::LR); const TargetRegisterClass *RC = XCore::GRRegsRegisterClass; XCoreFunctionInfo *XFI = MF.getInfo(); if (LRUsed) { MF.getRegInfo().setPhysRegUnused(XCore::LR); bool isVarArg = MF.getFunction()->isVarArg(); int FrameIdx; if (! isVarArg) { // A fixed offset of 0 allows us to save / restore LR using entsp / retsp. FrameIdx = MFI->CreateFixedObject(RC->getSize(), 0, true, false); } else { FrameIdx = MFI->CreateStackObject(RC->getSize(), RC->getAlignment(), false); } XFI->setUsesLR(FrameIdx); XFI->setLRSpillSlot(FrameIdx); } if (requiresRegisterScavenging(MF)) { // Reserve a slot close to SP or frame pointer. RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(), RC->getAlignment(), false)); } if (hasFP(MF)) { // A callee save register is used to hold the FP. // This needs saving / restoring in the epilogue / prologue. XFI->setFPSpillSlot(MFI->CreateStackObject(RC->getSize(), RC->getAlignment(), false)); } } void XCoreRegisterInfo:: processFunctionBeforeFrameFinalized(MachineFunction &MF) const { } void XCoreRegisterInfo:: loadConstant(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, unsigned DstReg, int64_t Value, DebugLoc dl) const { // TODO use mkmsk if possible. if (!isImmU16(Value)) { // TODO use constant pool. std::string msg; raw_string_ostream Msg(msg); Msg << "loadConstant value too big " << Value; llvm_report_error(Msg.str()); } int Opcode = isImmU6(Value) ? XCore::LDC_ru6 : XCore::LDC_lru6; BuildMI(MBB, I, dl, TII.get(Opcode), DstReg).addImm(Value); } void XCoreRegisterInfo:: storeToStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, unsigned SrcReg, int Offset, DebugLoc dl) const { assert(Offset%4 == 0 && "Misaligned stack offset"); Offset/=4; bool isU6 = isImmU6(Offset); if (!isU6 && !isImmU16(Offset)) { std::string msg; raw_string_ostream Msg(msg); Msg << "storeToStack offset too big " << Offset; llvm_report_error(Msg.str()); } int Opcode = isU6 ? XCore::STWSP_ru6 : XCore::STWSP_lru6; BuildMI(MBB, I, dl, TII.get(Opcode)) .addReg(SrcReg) .addImm(Offset); } void XCoreRegisterInfo:: loadFromStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, unsigned DstReg, int Offset, DebugLoc dl) const { assert(Offset%4 == 0 && "Misaligned stack offset"); Offset/=4; bool isU6 = isImmU6(Offset); if (!isU6 && !isImmU16(Offset)) { std::string msg; raw_string_ostream Msg(msg); Msg << "loadFromStack offset too big " << Offset; llvm_report_error(Msg.str()); } int Opcode = isU6 ? XCore::LDWSP_ru6 : XCore::LDWSP_lru6; BuildMI(MBB, I, dl, TII.get(Opcode), DstReg) .addImm(Offset); } void XCoreRegisterInfo::emitPrologue(MachineFunction &MF) const { MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB MachineBasicBlock::iterator MBBI = MBB.begin(); MachineFrameInfo *MFI = MF.getFrameInfo(); MachineModuleInfo *MMI = MFI->getMachineModuleInfo(); XCoreFunctionInfo *XFI = MF.getInfo(); DebugLoc dl = (MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc::getUnknownLoc()); bool FP = hasFP(MF); // Work out frame sizes. int FrameSize = MFI->getStackSize(); assert(FrameSize%4 == 0 && "Misaligned frame size"); FrameSize/=4; bool isU6 = isImmU6(FrameSize); if (!isU6 && !isImmU16(FrameSize)) { // FIXME could emit multiple instructions. std::string msg; raw_string_ostream Msg(msg); Msg << "emitPrologue Frame size too big: " << FrameSize; llvm_report_error(Msg.str()); } bool emitFrameMoves = needsFrameMoves(MF); // Do we need to allocate space on the stack? if (FrameSize) { bool saveLR = XFI->getUsesLR(); bool LRSavedOnEntry = false; int Opcode; if (saveLR && (MFI->getObjectOffset(XFI->getLRSpillSlot()) == 0)) { Opcode = (isU6) ? XCore::ENTSP_u6 : XCore::ENTSP_lu6; MBB.addLiveIn(XCore::LR); saveLR = false; LRSavedOnEntry = true; } else { Opcode = (isU6) ? XCore::EXTSP_u6 : XCore::EXTSP_lu6; } BuildMI(MBB, MBBI, dl, TII.get(Opcode)).addImm(FrameSize); if (emitFrameMoves) { std::vector &Moves = MMI->getFrameMoves(); // Show update of SP. unsigned FrameLabelId = MMI->NextLabelID(); BuildMI(MBB, MBBI, dl, TII.get(XCore::DBG_LABEL)).addImm(FrameLabelId); MachineLocation SPDst(MachineLocation::VirtualFP); MachineLocation SPSrc(MachineLocation::VirtualFP, -FrameSize * 4); Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc)); if (LRSavedOnEntry) { MachineLocation CSDst(MachineLocation::VirtualFP, 0); MachineLocation CSSrc(XCore::LR); Moves.push_back(MachineMove(FrameLabelId, CSDst, CSSrc)); } } if (saveLR) { int LRSpillOffset = MFI->getObjectOffset(XFI->getLRSpillSlot()); storeToStack(MBB, MBBI, XCore::LR, LRSpillOffset + FrameSize*4, dl); MBB.addLiveIn(XCore::LR); if (emitFrameMoves) { unsigned SaveLRLabelId = MMI->NextLabelID(); BuildMI(MBB, MBBI, dl, TII.get(XCore::DBG_LABEL)).addImm(SaveLRLabelId); MachineLocation CSDst(MachineLocation::VirtualFP, LRSpillOffset); MachineLocation CSSrc(XCore::LR); MMI->getFrameMoves().push_back(MachineMove(SaveLRLabelId, CSDst, CSSrc)); } } } if (FP) { // Save R10 to the stack. int FPSpillOffset = MFI->getObjectOffset(XFI->getFPSpillSlot()); storeToStack(MBB, MBBI, XCore::R10, FPSpillOffset + FrameSize*4, dl); // R10 is live-in. It is killed at the spill. MBB.addLiveIn(XCore::R10); if (emitFrameMoves) { unsigned SaveR10LabelId = MMI->NextLabelID(); BuildMI(MBB, MBBI, dl, TII.get(XCore::DBG_LABEL)).addImm(SaveR10LabelId); MachineLocation CSDst(MachineLocation::VirtualFP, FPSpillOffset); MachineLocation CSSrc(XCore::R10); MMI->getFrameMoves().push_back(MachineMove(SaveR10LabelId, CSDst, CSSrc)); } // Set the FP from the SP. unsigned FramePtr = XCore::R10; BuildMI(MBB, MBBI, dl, TII.get(XCore::LDAWSP_ru6), FramePtr) .addImm(0); if (emitFrameMoves) { // Show FP is now valid. unsigned FrameLabelId = MMI->NextLabelID(); BuildMI(MBB, MBBI, dl, TII.get(XCore::DBG_LABEL)).addImm(FrameLabelId); MachineLocation SPDst(FramePtr); MachineLocation SPSrc(MachineLocation::VirtualFP); MMI->getFrameMoves().push_back(MachineMove(FrameLabelId, SPDst, SPSrc)); } } if (emitFrameMoves) { // Frame moves for callee saved. std::vector &Moves = MMI->getFrameMoves(); std::vector >&SpillLabels = XFI->getSpillLabels(); for (unsigned I = 0, E = SpillLabels.size(); I != E; ++I) { unsigned SpillLabel = SpillLabels[I].first; CalleeSavedInfo &CSI = SpillLabels[I].second; int Offset = MFI->getObjectOffset(CSI.getFrameIdx()); unsigned Reg = CSI.getReg(); MachineLocation CSDst(MachineLocation::VirtualFP, Offset); MachineLocation CSSrc(Reg); Moves.push_back(MachineMove(SpillLabel, CSDst, CSSrc)); } } } void XCoreRegisterInfo::emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const { MachineFrameInfo *MFI = MF.getFrameInfo(); MachineBasicBlock::iterator MBBI = prior(MBB.end()); DebugLoc dl = MBBI->getDebugLoc(); bool FP = hasFP(MF); if (FP) { // Restore the stack pointer. unsigned FramePtr = XCore::R10; BuildMI(MBB, MBBI, dl, TII.get(XCore::SETSP_1r)) .addReg(FramePtr); } // Work out frame sizes. int FrameSize = MFI->getStackSize(); assert(FrameSize%4 == 0 && "Misaligned frame size"); FrameSize/=4; bool isU6 = isImmU6(FrameSize); if (!isU6 && !isImmU16(FrameSize)) { // FIXME could emit multiple instructions. std::string msg; raw_string_ostream Msg(msg); Msg << "emitEpilogue Frame size too big: " << FrameSize; llvm_report_error(Msg.str()); } if (FrameSize) { XCoreFunctionInfo *XFI = MF.getInfo(); if (FP) { // Restore R10 int FPSpillOffset = MFI->getObjectOffset(XFI->getFPSpillSlot()); FPSpillOffset += FrameSize*4; loadFromStack(MBB, MBBI, XCore::R10, FPSpillOffset, dl); } bool restoreLR = XFI->getUsesLR(); if (restoreLR && MFI->getObjectOffset(XFI->getLRSpillSlot()) != 0) { int LRSpillOffset = MFI->getObjectOffset(XFI->getLRSpillSlot()); LRSpillOffset += FrameSize*4; loadFromStack(MBB, MBBI, XCore::LR, LRSpillOffset, dl); restoreLR = false; } if (restoreLR) { // Fold prologue into return instruction assert(MBBI->getOpcode() == XCore::RETSP_u6 || MBBI->getOpcode() == XCore::RETSP_lu6); int Opcode = (isU6) ? XCore::RETSP_u6 : XCore::RETSP_lu6; BuildMI(MBB, MBBI, dl, TII.get(Opcode)).addImm(FrameSize); MBB.erase(MBBI); } else { int Opcode = (isU6) ? XCore::LDAWSP_ru6_RRegs : XCore::LDAWSP_lru6_RRegs; BuildMI(MBB, MBBI, dl, TII.get(Opcode), XCore::SP).addImm(FrameSize); } } } int XCoreRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const { return XCoreGenRegisterInfo::getDwarfRegNumFull(RegNum, 0); } unsigned XCoreRegisterInfo::getFrameRegister(const MachineFunction &MF) const { bool FP = hasFP(MF); return FP ? XCore::R10 : XCore::SP; } unsigned XCoreRegisterInfo::getRARegister() const { return XCore::LR; } void XCoreRegisterInfo::getInitialFrameState(std::vector &Moves) const { // Initial state of the frame pointer is SP. MachineLocation Dst(MachineLocation::VirtualFP); MachineLocation Src(XCore::SP, 0); Moves.push_back(MachineMove(0, Dst, Src)); } #include "XCoreGenRegisterInfo.inc"