1 //===-- PPCCodeEmitter.cpp - JIT Code Emitter for PowerPC32 -------*- C++ -*-=//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the PowerPC 32-bit CodeEmitter and associated machinery to
11 // JIT-compile bitcode to native PowerPC.
13 //===----------------------------------------------------------------------===//
15 #include "PPCTargetMachine.h"
16 #include "PPCRelocations.h"
18 #include "llvm/Module.h"
19 #include "llvm/PassManager.h"
20 #include "llvm/CodeGen/MachineCodeEmitter.h"
21 #include "llvm/CodeGen/MachineFunctionPass.h"
22 #include "llvm/CodeGen/MachineInstrBuilder.h"
23 #include "llvm/CodeGen/MachineModuleInfo.h"
24 #include "llvm/CodeGen/Passes.h"
25 #include "llvm/Support/Debug.h"
26 #include "llvm/Support/Compiler.h"
27 #include "llvm/Target/TargetOptions.h"
31 class VISIBILITY_HIDDEN PPCCodeEmitter : public MachineFunctionPass {
33 MachineCodeEmitter &MCE;
35 /// MovePCtoLROffset - When/if we see a MovePCtoLR instruction, we record
36 /// its address in the function into this pointer.
37 void *MovePCtoLROffset;
39 /// getMachineOpValue - evaluates the MachineOperand of a given MachineInstr
41 unsigned getMachineOpValue(const MachineInstr &MI, const MachineOperand &MO);
43 void getAnalysisUsage(AnalysisUsage &AU) const {
44 AU.addRequired<MachineModuleInfo>();
45 MachineFunctionPass::getAnalysisUsage(AU);
50 PPCCodeEmitter(TargetMachine &T, MachineCodeEmitter &M)
51 : MachineFunctionPass(&ID), TM(T), MCE(M) {}
53 const char *getPassName() const { return "PowerPC Machine Code Emitter"; }
55 /// runOnMachineFunction - emits the given MachineFunction to memory
57 bool runOnMachineFunction(MachineFunction &MF);
59 /// emitBasicBlock - emits the given MachineBasicBlock to memory
61 void emitBasicBlock(MachineBasicBlock &MBB);
63 /// getValueBit - return the particular bit of Val
65 unsigned getValueBit(int64_t Val, unsigned bit) { return (Val >> bit) & 1; }
67 /// getBinaryCodeForInstr - This function, generated by the
68 /// CodeEmitterGenerator using TableGen, produces the binary encoding for
69 /// machine instructions.
71 unsigned getBinaryCodeForInstr(const MachineInstr &MI);
73 char PPCCodeEmitter::ID = 0;
76 /// createPPCCodeEmitterPass - Return a pass that emits the collected PPC code
77 /// to the specified MCE object.
78 FunctionPass *llvm::createPPCCodeEmitterPass(PPCTargetMachine &TM,
79 MachineCodeEmitter &MCE) {
80 return new PPCCodeEmitter(TM, MCE);
83 bool PPCCodeEmitter::runOnMachineFunction(MachineFunction &MF) {
84 assert((MF.getTarget().getRelocationModel() != Reloc::Default ||
85 MF.getTarget().getRelocationModel() != Reloc::Static) &&
86 "JIT relocation model must be set to static or default!");
88 MCE.setModuleInfo(&getAnalysis<MachineModuleInfo>());
91 MCE.startFunction(MF);
92 for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); BB != E; ++BB)
94 } while (MCE.finishFunction(MF));
99 void PPCCodeEmitter::emitBasicBlock(MachineBasicBlock &MBB) {
100 MCE.StartMachineBasicBlock(&MBB);
102 for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ++I){
103 const MachineInstr &MI = *I;
104 switch (MI.getOpcode()) {
106 MCE.emitWordBE(getBinaryCodeForInstr(MI));
108 case TargetInstrInfo::DBG_LABEL:
109 case TargetInstrInfo::EH_LABEL:
110 MCE.emitLabel(MI.getOperand(0).getImm());
112 case TargetInstrInfo::IMPLICIT_DEF:
113 break; // pseudo opcode, no side effects
114 case PPC::MovePCtoLR:
115 case PPC::MovePCtoLR8:
116 assert(TM.getRelocationModel() == Reloc::PIC_);
117 MovePCtoLROffset = (void*)MCE.getCurrentPCValue();
118 MCE.emitWordBE(0x48000005); // bl 1
124 unsigned PPCCodeEmitter::getMachineOpValue(const MachineInstr &MI,
125 const MachineOperand &MO) {
127 unsigned rv = 0; // Return value; defaults to 0 for unhandled cases
128 // or things that get fixed up later by the JIT.
130 rv = PPCRegisterInfo::getRegisterNumbering(MO.getReg());
132 // Special encoding for MTCRF and MFOCRF, which uses a bit mask for the
133 // register, not the register number directly.
134 if ((MI.getOpcode() == PPC::MTCRF || MI.getOpcode() == PPC::MFOCRF) &&
135 (MO.getReg() >= PPC::CR0 && MO.getReg() <= PPC::CR7)) {
138 } else if (MO.isImm()) {
140 } else if (MO.isGlobal() || MO.isSymbol() ||
141 MO.isCPI() || MO.isJTI()) {
143 if (MI.getOpcode() == PPC::BL_Macho || MI.getOpcode() == PPC::BL8_Macho ||
144 MI.getOpcode() == PPC::BL_ELF || MI.getOpcode() == PPC::BL8_ELF ||
145 MI.getOpcode() == PPC::TAILB || MI.getOpcode() == PPC::TAILB8)
146 Reloc = PPC::reloc_pcrel_bx;
148 if (TM.getRelocationModel() == Reloc::PIC_) {
149 assert(MovePCtoLROffset && "MovePCtoLR not seen yet?");
151 switch (MI.getOpcode()) {
152 default: MI.dump(); assert(0 && "Unknown instruction for relocation!");
157 Reloc = PPC::reloc_absolute_high; // Pointer to symbol
183 Reloc = PPC::reloc_absolute_low;
190 Reloc = PPC::reloc_absolute_low_ix;
197 R = MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc,
199 isa<Function>(MO.getGlobal()));
200 } else if (MO.isSymbol()) {
201 R = MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
202 Reloc, MO.getSymbolName(), 0);
203 } else if (MO.isCPI()) {
204 R = MachineRelocation::getConstPool(MCE.getCurrentPCOffset(),
205 Reloc, MO.getIndex(), 0);
208 R = MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(),
209 Reloc, MO.getIndex(), 0);
212 // If in PIC mode, we need to encode the negated address of the
213 // 'movepctolr' into the unrelocated field. After relocation, we'll have
214 // &gv-&movepctolr-4 in the imm field. Once &movepctolr is added to the imm
215 // field, we get &gv. This doesn't happen for branch relocations, which are
216 // always implicitly pc relative.
217 if (TM.getRelocationModel() == Reloc::PIC_ && Reloc != PPC::reloc_pcrel_bx){
218 assert(MovePCtoLROffset && "MovePCtoLR not seen yet?");
219 R.setConstantVal(-(intptr_t)MovePCtoLROffset - 4);
221 MCE.addRelocation(R);
223 } else if (MO.isMBB()) {
225 unsigned Opcode = MI.getOpcode();
226 if (Opcode == PPC::B || Opcode == PPC::BL_Macho ||
227 Opcode == PPC::BLA_Macho || Opcode == PPC::BL_ELF ||
228 Opcode == PPC::BLA_ELF)
229 Reloc = PPC::reloc_pcrel_bx;
230 else // BCC instruction
231 Reloc = PPC::reloc_pcrel_bcx;
232 MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(),
233 Reloc, MO.getMBB()));
235 cerr << "ERROR: Unknown type of MachineOperand: " << MO << "\n";
242 #include "PPCGenCodeEmitter.inc"