diff options
author | Richard Osborne <richard@xmos.com> | 2008-11-07 10:59:00 +0000 |
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committer | Richard Osborne <richard@xmos.com> | 2008-11-07 10:59:00 +0000 |
commit | b25baef26f03b9909b65dd5f762b38f93000445d (patch) | |
tree | f03bc8e40b55feab99b0f32e4428d215fa45f988 /lib/Target/XCore/XCoreRegisterInfo.cpp | |
parent | 4df60f5491ff35c8a48c2cf14e18a33c9793b3bb (diff) |
Add XCore backend.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58838 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/XCore/XCoreRegisterInfo.cpp')
-rw-r--r-- | lib/Target/XCore/XCoreRegisterInfo.cpp | 596 |
1 files changed, 596 insertions, 0 deletions
diff --git a/lib/Target/XCore/XCoreRegisterInfo.cpp b/lib/Target/XCore/XCoreRegisterInfo.cpp new file mode 100644 index 0000000000..5293c82f13 --- /dev/null +++ b/lib/Target/XCore/XCoreRegisterInfo.cpp @@ -0,0 +1,596 @@ +//===- 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" + +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 <amt>' and the + // adjcallstackup instruction into 'ldaw sp, sp[<amt>]' + 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. + cerr << "eliminateCallFramePseudoInstr size too big: " + << Amount << "\n"; + abort(); + } + + MachineInstr *New; + if (Old->getOpcode() == XCore::ADJCALLSTACKDOWN) { + int Opcode = isU6 ? XCore::EXTSP_u6 : XCore::EXTSP_lu6; + New=BuildMI(MF, 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, TII.get(Opcode), XCore::SP) + .addImm(Amount); + } + + // Replace the pseudo instruction with a new instruction... + MBB.insert(I, New); + } + } + + MBB.erase(I); +} + +void XCoreRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, + int SPAdj, RegScavenger *RS) const { + assert(SPAdj == 0 && "Unexpected"); + MachineInstr &MI = *II; + 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 + DOUT << "\nFunction : " << MF.getFunction()->getName() << "\n"; + DOUT << "<--------->\n"; + MI.print(DOUT); + DOUT << "FrameIndex : " << FrameIndex << "\n"; + DOUT << "FrameOffset : " << Offset << "\n"; + DOUT << "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"); + + #ifndef NDEBUG + DOUT << "Offset : " << Offset << "\n"; + DOUT << "<--------->\n"; + #endif + + Offset/=4; + + bool FP = hasFP(MF); + + if (FP) { + bool isUs = isImmUs(Offset); + MachineBasicBlock &MBB = *MI.getParent(); + unsigned FramePtr = XCore::R10; + unsigned Reg = MI.getOperand(0).getReg(); + bool isKill = MI.getOperand(0).isKill(); + + if (Reg == XCore::LR) { + // The LR should have been save in the prologue. + cerr << "saving LR to FP unimplemented\n"; + abort(); + } + + MachineInstr *New = 0; + if (!isUs) { + if (!RS) { + cerr << "eliminateFrameIndex Frame size too big: " << Offset << "\n"; + abort(); + } + unsigned ScratchReg = RS->scavengeRegister(XCore::GRRegsRegisterClass, II, + SPAdj); + loadConstant(MBB, II, ScratchReg, Offset); + switch (MI.getOpcode()) { + case XCore::LDWSP_lru6: + New = BuildMI(MBB, II, TII.get(XCore::LDW_3r), Reg) + .addReg(FramePtr) + .addReg(ScratchReg, false, false, true); + break; + case XCore::STWSP_lru6: + New = BuildMI(MBB, II, TII.get(XCore::STW_3r)) + .addReg(Reg, false, false, isKill) + .addReg(FramePtr) + .addReg(ScratchReg, false, false, true); + break; + case XCore::LDAWSP_lru6: + New = BuildMI(MBB, II, TII.get(XCore::LDAWF_l3r), Reg) + .addReg(FramePtr) + .addReg(ScratchReg, false, false, true); + break; + default: + assert(0 && "Unexpected Opcode\n"); + } + } else { + switch (MI.getOpcode()) { + case XCore::LDWSP_lru6: + New = BuildMI(MBB, II, TII.get(XCore::LDW_2rus), Reg) + .addReg(FramePtr) + .addImm(Offset); + break; + case XCore::STWSP_lru6: + New = BuildMI(MBB, II, TII.get(XCore::STW_2rus)) + .addReg(Reg, false, false, isKill) + .addReg(FramePtr) + .addImm(Offset); + break; + case XCore::LDAWSP_lru6: + New = BuildMI(MBB, II, TII.get(XCore::LDAWF_l2rus), Reg) + .addReg(FramePtr) + .addImm(Offset); + break; + default: + assert(0 && "Unexpected Opcode\n"); + } + } + + // Erase old instruction. + MBB.erase(II); + } else { + bool isU6 = isImmU6(Offset); + if (!isU6 && !isImmU16(Offset)) { + // FIXME could make this work for LDWSP, LDAWSP. + cerr << "eliminateFrameIndex Frame size too big: " << Offset << "\n"; + abort(); + } + + int NewOpcode = MI.getOpcode(); + + switch (NewOpcode) { + case XCore::LDWSP_lru6: + NewOpcode = (isU6) ? XCore::LDWSP_ru6 : XCore::LDWSP_lru6; + break; + case XCore::STWSP_lru6: + NewOpcode = (isU6) ? XCore::STWSP_ru6 : XCore::STWSP_lru6; + break; + case XCore::LDAWSP_lru6: + NewOpcode = (isU6) ? XCore::LDAWSP_ru6 : XCore::LDAWSP_lru6; + break; + default: + assert(0 && "Unexpected Opcode\n"); + } + + MI.setDesc(TII.get(NewOpcode)); + FrameOp.ChangeToImmediate(Offset); + } +} + +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<XCoreFunctionInfo>(); + 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); + } else { + FrameIdx = MFI->CreateStackObject(RC->getSize(), RC->getAlignment()); + } + 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())); + } + 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())); + } +} + +void XCoreRegisterInfo:: +processFunctionBeforeFrameFinalized(MachineFunction &MF) const { + +} + +void XCoreRegisterInfo:: +loadConstant(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, + unsigned DstReg, int64_t Value) const { + // TODO use mkmsk if possible. + if (!isImmU16(Value)) { + // TODO use constant pool. + cerr << "loadConstant value too big " << Value << "\n"; + abort(); + } + int Opcode = isImmU6(Value) ? XCore::LDC_ru6 : XCore::LDC_lru6; + BuildMI(MBB, I, TII.get(Opcode), DstReg).addImm(Value); +} + +void XCoreRegisterInfo:: +storeToStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, + unsigned SrcReg, int Offset) const { + assert(Offset%4 == 0 && "Misaligned stack offset"); + Offset/=4; + bool isU6 = isImmU6(Offset); + if (!isU6 && !isImmU16(Offset)) { + cerr << "storeToStack offset too big " << Offset << "\n"; + abort(); + } + int Opcode = isU6 ? XCore::STWSP_ru6 : XCore::STWSP_lru6; + BuildMI(MBB, I, TII.get(Opcode)) + .addReg(SrcReg) + .addImm(Offset) + .addImm(0); +} + +void XCoreRegisterInfo:: +loadFromStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, + unsigned DstReg, int Offset) const { + assert(Offset%4 == 0 && "Misaligned stack offset"); + Offset/=4; + bool isU6 = isImmU6(Offset); + if (!isU6 && !isImmU16(Offset)) { + cerr << "storeToStack offset too big " << Offset << "\n"; + abort(); + } + int Opcode = isU6 ? XCore::LDWSP_ru6 : XCore::LDWSP_lru6; + BuildMI(MBB, I, TII.get(Opcode), DstReg) + .addImm(Offset) + .addImm(0); +} + +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<XCoreFunctionInfo>(); + + 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. + cerr << "emitPrologue Frame size too big: " << FrameSize << "\n"; + abort(); + } + 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, TII.get(Opcode)).addImm(FrameSize); + + if (emitFrameMoves) { + std::vector<MachineMove> &Moves = MMI->getFrameMoves(); + + // Show update of SP. + unsigned FrameLabelId = MMI->NextLabelID(); + BuildMI(MBB, MBBI, 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); + MBB.addLiveIn(XCore::LR); + + if (emitFrameMoves) { + unsigned SaveLRLabelId = MMI->NextLabelID(); + BuildMI(MBB, MBBI, 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); + // R10 is live-in. It is killed at the spill. + MBB.addLiveIn(XCore::R10); + if (emitFrameMoves) { + unsigned SaveR10LabelId = MMI->NextLabelID(); + BuildMI(MBB, MBBI, 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, TII.get(XCore::LDAWSP_ru6), FramePtr) + .addImm(0) + .addImm(0); + if (emitFrameMoves) { + // Show FP is now valid. + unsigned FrameLabelId = MMI->NextLabelID(); + BuildMI(MBB, MBBI, 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<MachineMove> &Moves = MMI->getFrameMoves(); + std::vector<std::pair<unsigned, CalleeSavedInfo> >&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()); + + bool FP = hasFP(MF); + + if (FP) { + // Restore the stack pointer. + unsigned FramePtr = XCore::R10; + BuildMI(MBB, MBBI, 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. + cerr << "emitEpilogue Frame size too big: " << FrameSize << "\n"; + abort(); + } + + if (FrameSize) { + XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>(); + + if (FP) { + // Restore R10 + int FPSpillOffset = MFI->getObjectOffset(XFI->getFPSpillSlot()); + FPSpillOffset += FrameSize*4; + loadFromStack(MBB, MBBI, XCore::R10, FPSpillOffset); + } + 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); + 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, TII.get(Opcode)).addImm(FrameSize); + MBB.erase(MBBI); + } else { + int Opcode = (isU6) ? XCore::LDAWSP_ru6_RRegs : XCore::LDAWSP_lru6_RRegs; + BuildMI(MBB, MBBI, TII.get(Opcode), XCore::SP).addImm(FrameSize); + } + } +} + +int XCoreRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const { + return XCoreGenRegisterInfo::getDwarfRegNumFull(RegNum, 0); +} + +unsigned XCoreRegisterInfo::getFrameRegister(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<MachineMove> &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" + |