|  | //===-- PPCCodeEmitter.cpp - JIT Code Emitter for PowerPC32 -------*- C++ -*-=// | 
|  | // | 
|  | //                     The LLVM Compiler Infrastructure | 
|  | // | 
|  | // This file is distributed under the University of Illinois Open Source | 
|  | // License. See LICENSE.TXT for details. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  | // | 
|  | // This file defines the PowerPC 32-bit CodeEmitter and associated machinery to | 
|  | // JIT-compile bitcode to native PowerPC. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #include "PPCTargetMachine.h" | 
|  | #include "PPCRelocations.h" | 
|  | #include "PPC.h" | 
|  | #include "llvm/Module.h" | 
|  | #include "llvm/PassManager.h" | 
|  | #include "llvm/CodeGen/MachineCodeEmitter.h" | 
|  | #include "llvm/CodeGen/JITCodeEmitter.h" | 
|  | #include "llvm/CodeGen/ObjectCodeEmitter.h" | 
|  | #include "llvm/CodeGen/MachineFunctionPass.h" | 
|  | #include "llvm/CodeGen/MachineInstrBuilder.h" | 
|  | #include "llvm/CodeGen/MachineModuleInfo.h" | 
|  | #include "llvm/CodeGen/Passes.h" | 
|  | #include "llvm/Support/Debug.h" | 
|  | #include "llvm/Support/Compiler.h" | 
|  | #include "llvm/Support/ErrorHandling.h" | 
|  | #include "llvm/Support/raw_ostream.h" | 
|  | #include "llvm/Target/TargetOptions.h" | 
|  | using namespace llvm; | 
|  |  | 
|  | namespace { | 
|  | class PPCCodeEmitter { | 
|  | TargetMachine &TM; | 
|  | MachineCodeEmitter &MCE; | 
|  | public: | 
|  | PPCCodeEmitter(TargetMachine &tm, MachineCodeEmitter &mce): | 
|  | TM(tm), MCE(mce) {} | 
|  |  | 
|  | /// getBinaryCodeForInstr - This function, generated by the | 
|  | /// CodeEmitterGenerator using TableGen, produces the binary encoding for | 
|  | /// machine instructions. | 
|  |  | 
|  | unsigned getBinaryCodeForInstr(const MachineInstr &MI); | 
|  |  | 
|  | /// getMachineOpValue - evaluates the MachineOperand of a given MachineInstr | 
|  |  | 
|  | unsigned getMachineOpValue(const MachineInstr &MI, | 
|  | const MachineOperand &MO); | 
|  |  | 
|  | /// MovePCtoLROffset - When/if we see a MovePCtoLR instruction, we record | 
|  | /// its address in the function into this pointer. | 
|  |  | 
|  | void *MovePCtoLROffset; | 
|  | }; | 
|  |  | 
|  | template <class CodeEmitter> | 
|  | class VISIBILITY_HIDDEN Emitter : public MachineFunctionPass, | 
|  | public PPCCodeEmitter { | 
|  | TargetMachine &TM; | 
|  | CodeEmitter &MCE; | 
|  |  | 
|  | void getAnalysisUsage(AnalysisUsage &AU) const { | 
|  | AU.addRequired<MachineModuleInfo>(); | 
|  | MachineFunctionPass::getAnalysisUsage(AU); | 
|  | } | 
|  |  | 
|  | public: | 
|  | static char ID; | 
|  | Emitter(TargetMachine &tm, CodeEmitter &mce) | 
|  | : MachineFunctionPass(&ID), PPCCodeEmitter(tm, mce), TM(tm), MCE(mce) {} | 
|  |  | 
|  | const char *getPassName() const { return "PowerPC Machine Code Emitter"; } | 
|  |  | 
|  | /// runOnMachineFunction - emits the given MachineFunction to memory | 
|  | /// | 
|  | bool runOnMachineFunction(MachineFunction &MF); | 
|  |  | 
|  | /// emitBasicBlock - emits the given MachineBasicBlock to memory | 
|  | /// | 
|  | void emitBasicBlock(MachineBasicBlock &MBB); | 
|  |  | 
|  | /// getValueBit - return the particular bit of Val | 
|  | /// | 
|  | unsigned getValueBit(int64_t Val, unsigned bit) { return (Val >> bit) & 1; } | 
|  | }; | 
|  |  | 
|  | template <class CodeEmitter> | 
|  | char Emitter<CodeEmitter>::ID = 0; | 
|  | } | 
|  |  | 
|  | /// createPPCCodeEmitterPass - Return a pass that emits the collected PPC code | 
|  | /// to the specified MCE object. | 
|  |  | 
|  | FunctionPass *llvm::createPPCCodeEmitterPass(PPCTargetMachine &TM, | 
|  | MachineCodeEmitter &MCE) { | 
|  | return new Emitter<MachineCodeEmitter>(TM, MCE); | 
|  | } | 
|  |  | 
|  | FunctionPass *llvm::createPPCJITCodeEmitterPass(PPCTargetMachine &TM, | 
|  | JITCodeEmitter &JCE) { | 
|  | return new Emitter<JITCodeEmitter>(TM, JCE); | 
|  | } | 
|  |  | 
|  | FunctionPass *llvm::createPPCObjectCodeEmitterPass(PPCTargetMachine &TM, | 
|  | ObjectCodeEmitter &OCE) { | 
|  | return new Emitter<ObjectCodeEmitter>(TM, OCE); | 
|  | } | 
|  |  | 
|  | template <class CodeEmitter> | 
|  | bool Emitter<CodeEmitter>::runOnMachineFunction(MachineFunction &MF) { | 
|  | assert((MF.getTarget().getRelocationModel() != Reloc::Default || | 
|  | MF.getTarget().getRelocationModel() != Reloc::Static) && | 
|  | "JIT relocation model must be set to static or default!"); | 
|  |  | 
|  | MCE.setModuleInfo(&getAnalysis<MachineModuleInfo>()); | 
|  | do { | 
|  | MovePCtoLROffset = 0; | 
|  | MCE.startFunction(MF); | 
|  | for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); BB != E; ++BB) | 
|  | emitBasicBlock(*BB); | 
|  | } while (MCE.finishFunction(MF)); | 
|  |  | 
|  | return false; | 
|  | } | 
|  |  | 
|  | template <class CodeEmitter> | 
|  | void Emitter<CodeEmitter>::emitBasicBlock(MachineBasicBlock &MBB) { | 
|  | MCE.StartMachineBasicBlock(&MBB); | 
|  |  | 
|  | for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ++I){ | 
|  | const MachineInstr &MI = *I; | 
|  | MCE.processDebugLoc(MI.getDebugLoc()); | 
|  | switch (MI.getOpcode()) { | 
|  | default: | 
|  | MCE.emitWordBE(getBinaryCodeForInstr(MI)); | 
|  | break; | 
|  | case TargetInstrInfo::DBG_LABEL: | 
|  | case TargetInstrInfo::EH_LABEL: | 
|  | MCE.emitLabel(MI.getOperand(0).getImm()); | 
|  | break; | 
|  | case TargetInstrInfo::IMPLICIT_DEF: | 
|  | break; // pseudo opcode, no side effects | 
|  | case PPC::MovePCtoLR: | 
|  | case PPC::MovePCtoLR8: | 
|  | assert(TM.getRelocationModel() == Reloc::PIC_); | 
|  | MovePCtoLROffset = (void*)MCE.getCurrentPCValue(); | 
|  | MCE.emitWordBE(0x48000005);   // bl 1 | 
|  | break; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | unsigned PPCCodeEmitter::getMachineOpValue(const MachineInstr &MI, | 
|  | const MachineOperand &MO) { | 
|  |  | 
|  | unsigned rv = 0; // Return value; defaults to 0 for unhandled cases | 
|  | // or things that get fixed up later by the JIT. | 
|  | if (MO.isReg()) { | 
|  | rv = PPCRegisterInfo::getRegisterNumbering(MO.getReg()); | 
|  |  | 
|  | // Special encoding for MTCRF and MFOCRF, which uses a bit mask for the | 
|  | // register, not the register number directly. | 
|  | if ((MI.getOpcode() == PPC::MTCRF || MI.getOpcode() == PPC::MFOCRF) && | 
|  | (MO.getReg() >= PPC::CR0 && MO.getReg() <= PPC::CR7)) { | 
|  | rv = 0x80 >> rv; | 
|  | } | 
|  | } else if (MO.isImm()) { | 
|  | rv = MO.getImm(); | 
|  | } else if (MO.isGlobal() || MO.isSymbol() || | 
|  | MO.isCPI() || MO.isJTI()) { | 
|  | unsigned Reloc = 0; | 
|  | if (MI.getOpcode() == PPC::BL_Darwin || MI.getOpcode() == PPC::BL8_Darwin || | 
|  | MI.getOpcode() == PPC::BL_SVR4 || MI.getOpcode() == PPC::BL8_ELF || | 
|  | MI.getOpcode() == PPC::TAILB || MI.getOpcode() == PPC::TAILB8) | 
|  | Reloc = PPC::reloc_pcrel_bx; | 
|  | else { | 
|  | if (TM.getRelocationModel() == Reloc::PIC_) { | 
|  | assert(MovePCtoLROffset && "MovePCtoLR not seen yet?"); | 
|  | } | 
|  | switch (MI.getOpcode()) { | 
|  | default: MI.dump(); llvm_unreachable("Unknown instruction for relocation!"); | 
|  | case PPC::LIS: | 
|  | case PPC::LIS8: | 
|  | case PPC::ADDIS: | 
|  | case PPC::ADDIS8: | 
|  | Reloc = PPC::reloc_absolute_high;       // Pointer to symbol | 
|  | break; | 
|  | case PPC::LI: | 
|  | case PPC::LI8: | 
|  | case PPC::LA: | 
|  | // Loads. | 
|  | case PPC::LBZ: | 
|  | case PPC::LBZ8: | 
|  | case PPC::LHA: | 
|  | case PPC::LHA8: | 
|  | case PPC::LHZ: | 
|  | case PPC::LHZ8: | 
|  | case PPC::LWZ: | 
|  | case PPC::LWZ8: | 
|  | case PPC::LFS: | 
|  | case PPC::LFD: | 
|  |  | 
|  | // Stores. | 
|  | case PPC::STB: | 
|  | case PPC::STB8: | 
|  | case PPC::STH: | 
|  | case PPC::STH8: | 
|  | case PPC::STW: | 
|  | case PPC::STW8: | 
|  | case PPC::STFS: | 
|  | case PPC::STFD: | 
|  | Reloc = PPC::reloc_absolute_low; | 
|  | break; | 
|  |  | 
|  | case PPC::LWA: | 
|  | case PPC::LD: | 
|  | case PPC::STD: | 
|  | case PPC::STD_32: | 
|  | Reloc = PPC::reloc_absolute_low_ix; | 
|  | break; | 
|  | } | 
|  | } | 
|  |  | 
|  | MachineRelocation R; | 
|  | if (MO.isGlobal()) { | 
|  | R = MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc, | 
|  | MO.getGlobal(), 0, | 
|  | isa<Function>(MO.getGlobal())); | 
|  | } else if (MO.isSymbol()) { | 
|  | R = MachineRelocation::getExtSym(MCE.getCurrentPCOffset(), | 
|  | Reloc, MO.getSymbolName(), 0); | 
|  | } else if (MO.isCPI()) { | 
|  | R = MachineRelocation::getConstPool(MCE.getCurrentPCOffset(), | 
|  | Reloc, MO.getIndex(), 0); | 
|  | } else { | 
|  | assert(MO.isJTI()); | 
|  | R = MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(), | 
|  | Reloc, MO.getIndex(), 0); | 
|  | } | 
|  |  | 
|  | // If in PIC mode, we need to encode the negated address of the | 
|  | // 'movepctolr' into the unrelocated field.  After relocation, we'll have | 
|  | // &gv-&movepctolr-4 in the imm field.  Once &movepctolr is added to the imm | 
|  | // field, we get &gv.  This doesn't happen for branch relocations, which are | 
|  | // always implicitly pc relative. | 
|  | if (TM.getRelocationModel() == Reloc::PIC_ && Reloc != PPC::reloc_pcrel_bx){ | 
|  | assert(MovePCtoLROffset && "MovePCtoLR not seen yet?"); | 
|  | R.setConstantVal(-(intptr_t)MovePCtoLROffset - 4); | 
|  | } | 
|  | MCE.addRelocation(R); | 
|  |  | 
|  | } else if (MO.isMBB()) { | 
|  | unsigned Reloc = 0; | 
|  | unsigned Opcode = MI.getOpcode(); | 
|  | if (Opcode == PPC::B || Opcode == PPC::BL_Darwin || | 
|  | Opcode == PPC::BLA_Darwin|| Opcode == PPC::BL_SVR4 || | 
|  | Opcode == PPC::BLA_SVR4) | 
|  | Reloc = PPC::reloc_pcrel_bx; | 
|  | else // BCC instruction | 
|  | Reloc = PPC::reloc_pcrel_bcx; | 
|  |  | 
|  | MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(), | 
|  | Reloc, MO.getMBB())); | 
|  | } else { | 
|  | #ifndef NDEBUG | 
|  | errs() << "ERROR: Unknown type of MachineOperand: " << MO << "\n"; | 
|  | #endif | 
|  | llvm_unreachable(0); | 
|  | } | 
|  |  | 
|  | return rv; | 
|  | } | 
|  |  | 
|  | #include "PPCGenCodeEmitter.inc" |