1 //===-- PPC32CodeEmitter.cpp - JIT Code Emitter for PowerPC32 -----*- C++ -*-=//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the PowerPC 32-bit CodeEmitter and associated machinery to
11 // JIT-compile bytecode to native PowerPC.
13 //===----------------------------------------------------------------------===//
15 #include "PPC32JITInfo.h"
16 #include "PPC32TargetMachine.h"
18 #include "llvm/Module.h"
19 #include "llvm/CodeGen/MachineCodeEmitter.h"
20 #include "llvm/CodeGen/MachineFunctionPass.h"
21 #include "llvm/CodeGen/MachineInstrBuilder.h"
22 #include "llvm/CodeGen/Passes.h"
23 #include "llvm/Support/Debug.h"
29 MachineCodeEmitter &MCE;
31 // LazyCodeGenMap - Keep track of call sites for functions that are to be
33 std::map<unsigned, Function*> LazyCodeGenMap;
35 // LazyResolverMap - Keep track of the lazy resolver created for a
36 // particular function so that we can reuse them if necessary.
37 std::map<Function*, unsigned> LazyResolverMap;
40 JITResolver(MachineCodeEmitter &mce) : MCE(mce) {}
41 unsigned getLazyResolver(Function *F);
42 unsigned addFunctionReference(unsigned Address, Function *F);
45 unsigned emitStubForFunction(Function *F);
46 static void CompilationCallback();
47 unsigned resolveFunctionReference(unsigned RetAddr);
50 static JITResolver &getResolver(MachineCodeEmitter &MCE) {
51 static JITResolver *TheJITResolver = 0;
52 if (TheJITResolver == 0)
53 TheJITResolver = new JITResolver(MCE);
54 return *TheJITResolver;
58 unsigned JITResolver::getLazyResolver(Function *F) {
59 std::map<Function*, unsigned>::iterator I = LazyResolverMap.lower_bound(F);
60 if (I != LazyResolverMap.end() && I->first == F) return I->second;
62 unsigned Stub = emitStubForFunction(F);
63 LazyResolverMap.insert(I, std::make_pair(F, Stub));
67 /// addFunctionReference - This method is called when we need to emit the
68 /// address of a function that has not yet been emitted, so we don't know the
69 /// address. Instead, we emit a call to the CompilationCallback method, and
70 /// keep track of where we are.
72 unsigned JITResolver::addFunctionReference(unsigned Address, Function *F) {
73 LazyCodeGenMap[Address] = F;
74 return (intptr_t)&JITResolver::CompilationCallback;
77 unsigned JITResolver::resolveFunctionReference(unsigned RetAddr) {
78 std::map<unsigned, Function*>::iterator I = LazyCodeGenMap.find(RetAddr);
79 assert(I != LazyCodeGenMap.end() && "Not in map!");
80 Function *F = I->second;
81 LazyCodeGenMap.erase(I);
82 return MCE.forceCompilationOf(F);
85 /// emitStubForFunction - This method is used by the JIT when it needs to emit
86 /// the address of a function for a function whose code has not yet been
87 /// generated. In order to do this, it generates a stub which jumps to the lazy
88 /// function compiler, which will eventually get fixed to call the function
91 unsigned JITResolver::emitStubForFunction(Function *F) {
92 std::cerr << "PPC32CodeEmitter::emitStubForFunction() unimplemented!\n";
97 void JITResolver::CompilationCallback() {
98 std::cerr << "PPC32CodeEmitter: CompilationCallback() unimplemented!";
103 class PPC32CodeEmitter : public MachineFunctionPass {
105 MachineCodeEmitter &MCE;
107 // Tracks which instruction references which BasicBlock
108 std::vector<std::pair<const BasicBlock*,
109 std::pair<unsigned*,MachineInstr*> > > BBRefs;
110 // Tracks where each BasicBlock starts
111 std::map<const BasicBlock*, long> BBLocations;
113 /// getMachineOpValue - evaluates the MachineOperand of a given MachineInstr
115 int64_t getMachineOpValue(MachineInstr &MI, MachineOperand &MO);
117 unsigned getAddressOfExternalFunction(Function *F);
120 PPC32CodeEmitter(TargetMachine &T, MachineCodeEmitter &M)
123 const char *getPassName() const { return "PowerPC Machine Code Emitter"; }
125 /// runOnMachineFunction - emits the given MachineFunction to memory
127 bool runOnMachineFunction(MachineFunction &MF);
129 /// emitBasicBlock - emits the given MachineBasicBlock to memory
131 void emitBasicBlock(MachineBasicBlock &MBB);
133 /// emitWord - write a 32-bit word to memory at the current PC
135 void emitWord(unsigned w) { MCE.emitWord(w); }
137 /// getValueBit - return the particular bit of Val
139 unsigned getValueBit(int64_t Val, unsigned bit) { return (Val >> bit) & 1; }
141 /// getBinaryCodeForInstr - This function, generated by the
142 /// CodeEmitterGenerator using TableGen, produces the binary encoding for
143 /// machine instructions.
145 unsigned getBinaryCodeForInstr(MachineInstr &MI);
149 /// addPassesToEmitMachineCode - Add passes to the specified pass manager to get
150 /// machine code emitted. This uses a MachineCodeEmitter object to handle
151 /// actually outputting the machine code and resolving things like the address
152 /// of functions. This method should returns true if machine code emission is
155 bool PPC32TargetMachine::addPassesToEmitMachineCode(FunctionPassManager &PM,
156 MachineCodeEmitter &MCE) {
157 // Keep as `true' until this is a functional JIT to allow llvm-gcc to build
160 // Machine code emitter pass for PowerPC
161 PM.add(new PPC32CodeEmitter(*this, MCE));
162 // Delete machine code for this function after emitting it
163 PM.add(createMachineCodeDeleter());
167 bool PPC32CodeEmitter::runOnMachineFunction(MachineFunction &MF) {
168 MCE.startFunction(MF);
169 MCE.emitConstantPool(MF.getConstantPool());
170 for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); BB != E; ++BB)
172 MCE.finishFunction(MF);
174 // Resolve branches to BasicBlocks for the entire function
175 for (unsigned i = 0, e = BBRefs.size(); i != e; ++i) {
176 long Location = BBLocations[BBRefs[i].first];
177 unsigned *Ref = BBRefs[i].second.first;
178 MachineInstr *MI = BBRefs[i].second.second;
179 DEBUG(std::cerr << "Fixup @ " << std::hex << Ref << " to 0x" << Location
180 << " in instr: " << std::dec << *MI);
181 for (unsigned ii = 0, ee = MI->getNumOperands(); ii != ee; ++ii) {
182 MachineOperand &op = MI->getOperand(ii);
183 if (op.isPCRelativeDisp()) {
184 // the instruction's branch target is made such that it branches to
185 // PC + (branchTarget * 4), so undo that arithmetic here:
186 // Location is the target of the branch
187 // Ref is the location of the instruction, and hence the PC
188 int64_t branchTarget = (Location - (long)Ref) >> 2;
189 MI->SetMachineOperandConst(ii, MachineOperand::MO_SignExtendedImmed,
191 unsigned fixedInstr = PPC32CodeEmitter::getBinaryCodeForInstr(*MI);
192 MCE.emitWordAt(fixedInstr, Ref);
203 void PPC32CodeEmitter::emitBasicBlock(MachineBasicBlock &MBB) {
204 BBLocations[MBB.getBasicBlock()] = MCE.getCurrentPCValue();
205 for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ++I){
206 MachineInstr &MI = *I;
207 unsigned Opcode = MI.getOpcode();
208 if (Opcode == PPC::IMPLICIT_DEF)
209 continue; // pseudo opcode, no side effects
210 else if (Opcode == PPC::MovePCtoLR) {
211 // This can be simplified: the resulting 32-bit code is 0x48000005
212 MachineInstr *MI = BuildMI(PPC::BL, 1).addImm(1);
213 emitWord(getBinaryCodeForInstr(*MI));
216 emitWord(getBinaryCodeForInstr(*I));
220 unsigned PPC32CodeEmitter::getAddressOfExternalFunction(Function *F) {
221 static std::map<Function*, unsigned> ExternalFn2Addr;
222 std::map<Function*, unsigned>::iterator Addr = ExternalFn2Addr.find(F);
224 if (Addr == ExternalFn2Addr.end())
225 ExternalFn2Addr[F] = MCE.forceCompilationOf(F);
226 return ExternalFn2Addr[F];
229 static unsigned enumRegToMachineReg(unsigned enumReg) {
231 case PPC::R0 : case PPC::F0 : return 0;
232 case PPC::R1 : case PPC::F1 : return 1;
233 case PPC::R2 : case PPC::F2 : return 2;
234 case PPC::R3 : case PPC::F3 : return 3;
235 case PPC::R4 : case PPC::F4 : return 4;
236 case PPC::R5 : case PPC::F5 : return 5;
237 case PPC::R6 : case PPC::F6 : return 6;
238 case PPC::R7 : case PPC::F7 : return 7;
239 case PPC::R8 : case PPC::F8 : return 8;
240 case PPC::R9 : case PPC::F9 : return 9;
241 case PPC::R10: case PPC::F10: return 10;
242 case PPC::R11: case PPC::F11: return 11;
243 case PPC::R12: case PPC::F12: return 12;
244 case PPC::R13: case PPC::F13: return 13;
245 case PPC::R14: case PPC::F14: return 14;
246 case PPC::R15: case PPC::F15: return 15;
247 case PPC::R16: case PPC::F16: return 16;
248 case PPC::R17: case PPC::F17: return 17;
249 case PPC::R18: case PPC::F18: return 18;
250 case PPC::R19: case PPC::F19: return 19;
251 case PPC::R20: case PPC::F20: return 20;
252 case PPC::R21: case PPC::F21: return 21;
253 case PPC::R22: case PPC::F22: return 22;
254 case PPC::R23: case PPC::F23: return 23;
255 case PPC::R24: case PPC::F24: return 24;
256 case PPC::R25: case PPC::F25: return 25;
257 case PPC::R26: case PPC::F26: return 26;
258 case PPC::R27: case PPC::F27: return 27;
259 case PPC::R28: case PPC::F28: return 28;
260 case PPC::R29: case PPC::F29: return 29;
261 case PPC::R30: case PPC::F30: return 30;
262 case PPC::R31: case PPC::F31: return 31;
264 std::cerr << "Unhandled reg in enumRegToRealReg!\n";
269 int64_t PPC32CodeEmitter::getMachineOpValue(MachineInstr &MI,
270 MachineOperand &MO) {
271 int64_t rv = 0; // Return value; defaults to 0 for unhandled cases
272 // or things that get fixed up later by the JIT.
273 if (MO.isRegister()) {
274 rv = enumRegToMachineReg(MO.getReg());
275 } else if (MO.isImmediate()) {
276 rv = MO.getImmedValue();
277 } else if (MO.isGlobalAddress()) {
278 GlobalValue *GV = MO.getGlobal();
279 rv = MCE.getGlobalValueAddress(GV);
281 if (Function *F = dyn_cast<Function>(GV)) {
283 rv = getAddressOfExternalFunction(F);
285 // Function has not yet been code generated! Use lazy resolution.
286 getResolver(MCE).addFunctionReference(MCE.getCurrentPCValue(), F);
287 rv = getResolver(MCE).getLazyResolver(F);
289 } else if (GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) {
290 if (GVar->isExternal()) {
291 rv = MCE.getGlobalValueAddress(MO.getSymbolName());
293 std::cerr << "PPC32CodeEmitter: External global addr not found: "
298 std::cerr << "PPC32CodeEmitter: global addr not found: " << *GVar;
303 if (MO.isPCRelative()) { // Global variable reference
304 rv = (rv - MCE.getCurrentPCValue()) >> 2;
306 } else if (MO.isMachineBasicBlock()) {
307 const BasicBlock *BB = MO.getMachineBasicBlock()->getBasicBlock();
308 unsigned* CurrPC = (unsigned*)(intptr_t)MCE.getCurrentPCValue();
309 BBRefs.push_back(std::make_pair(BB, std::make_pair(CurrPC, &MI)));
310 } else if (MO.isConstantPoolIndex()) {
311 unsigned index = MO.getConstantPoolIndex();
312 rv = MCE.getConstantPoolEntryAddress(index);
313 } else if (MO.isFrameIndex()) {
314 std::cerr << "PPC32CodeEmitter: error: Frame index unhandled!\n";
317 std::cerr << "ERROR: Unknown type of MachineOperand: " << MO << "\n";
321 // Special treatment for global symbols: constants and vars
322 if (MO.isConstantPoolIndex() || MO.isGlobalAddress()) {
323 unsigned Opcode = MI.getOpcode();
324 int64_t MBBLoc = BBLocations[MI.getParent()->getBasicBlock()];
325 if (Opcode == PPC::LOADHiAddr) {
326 // LoadHiAddr wants hi16(addr - mbb)
327 rv = (rv - MBBLoc) >> 16;
328 } else if (Opcode == PPC::LWZ || Opcode == PPC::LA ||
329 Opcode == PPC::LFS || Opcode == PPC::LFD) {
330 // These load opcodes want lo16(addr - mbb)
331 rv = (rv - MBBLoc) & 0xffff;
339 void *PPC32JITInfo::getJITStubForFunction(Function *F, MachineCodeEmitter &MCE){
340 return (void*)((unsigned long)getResolver(MCE).getLazyResolver(F));
343 void PPC32JITInfo::replaceMachineCodeForFunction (void *Old, void *New) {
344 std::cerr << "PPC32JITInfo::replaceMachineCodeForFunction not implemented\n";
348 #include "PPC32GenCodeEmitter.inc"
350 } // end llvm namespace