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"
27 class PPC32CodeEmitter : public MachineFunctionPass {
29 MachineCodeEmitter &MCE;
31 // Tracks which instruction references which BasicBlock
32 std::vector<std::pair<const BasicBlock*,
33 std::pair<unsigned*,MachineInstr*> > > BBRefs;
34 // Tracks where each BasicBlock starts
35 std::map<const BasicBlock*, long> BBLocations;
37 /// getMachineOpValue - evaluates the MachineOperand of a given MachineInstr
39 int64_t getMachineOpValue(MachineInstr &MI, MachineOperand &MO);
41 unsigned getAddressOfExternalFunction(Function *F);
44 PPC32CodeEmitter(TargetMachine &T, MachineCodeEmitter &M)
47 const char *getPassName() const { return "PowerPC Machine Code Emitter"; }
49 /// runOnMachineFunction - emits the given MachineFunction to memory
51 bool runOnMachineFunction(MachineFunction &MF);
53 /// emitBasicBlock - emits the given MachineBasicBlock to memory
55 void emitBasicBlock(MachineBasicBlock &MBB);
57 /// emitWord - write a 32-bit word to memory at the current PC
59 void emitWord(unsigned w) { MCE.emitWord(w); }
61 /// getValueBit - return the particular bit of Val
63 unsigned getValueBit(int64_t Val, unsigned bit) { return (Val >> bit) & 1; }
65 /// getBinaryCodeForInstr - This function, generated by the
66 /// CodeEmitterGenerator using TableGen, produces the binary encoding for
67 /// machine instructions.
69 unsigned getBinaryCodeForInstr(MachineInstr &MI);
73 /// addPassesToEmitMachineCode - Add passes to the specified pass manager to get
74 /// machine code emitted. This uses a MachineCodeEmitter object to handle
75 /// actually outputting the machine code and resolving things like the address
76 /// of functions. This method should returns true if machine code emission is
79 bool PPC32TargetMachine::addPassesToEmitMachineCode(FunctionPassManager &PM,
80 MachineCodeEmitter &MCE) {
81 // Keep as `true' until this is a functional JIT to allow llvm-gcc to build
84 // Machine code emitter pass for PowerPC
85 PM.add(new PPC32CodeEmitter(*this, MCE));
86 // Delete machine code for this function after emitting it
87 PM.add(createMachineCodeDeleter());
91 bool PPC32CodeEmitter::runOnMachineFunction(MachineFunction &MF) {
92 MCE.startFunction(MF);
93 MCE.emitConstantPool(MF.getConstantPool());
94 for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); BB != E; ++BB)
96 MCE.finishFunction(MF);
98 // Resolve branches to BasicBlocks for the entire function
99 for (unsigned i = 0, e = BBRefs.size(); i != e; ++i) {
100 long Location = BBLocations[BBRefs[i].first];
101 unsigned *Ref = BBRefs[i].second.first;
102 MachineInstr *MI = BBRefs[i].second.second;
103 DEBUG(std::cerr << "Fixup @ " << std::hex << Ref << " to 0x" << Location
104 << " in instr: " << std::dec << *MI);
105 for (unsigned ii = 0, ee = MI->getNumOperands(); ii != ee; ++ii) {
106 MachineOperand &op = MI->getOperand(ii);
107 if (op.isPCRelativeDisp()) {
108 // the instruction's branch target is made such that it branches to
109 // PC + (branchTarget * 4), so undo that arithmetic here:
110 // Location is the target of the branch
111 // Ref is the location of the instruction, and hence the PC
112 int64_t branchTarget = (Location - (long)Ref) >> 2;
113 MI->SetMachineOperandConst(ii, MachineOperand::MO_SignExtendedImmed,
115 unsigned fixedInstr = PPC32CodeEmitter::getBinaryCodeForInstr(*MI);
116 MCE.emitWordAt(fixedInstr, Ref);
127 void PPC32CodeEmitter::emitBasicBlock(MachineBasicBlock &MBB) {
128 BBLocations[MBB.getBasicBlock()] = MCE.getCurrentPCValue();
129 for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ++I){
130 MachineInstr &MI = *I;
131 unsigned Opcode = MI.getOpcode();
132 if (Opcode == PPC::IMPLICIT_DEF)
133 continue; // pseudo opcode, no side effects
134 else if (Opcode == PPC::MovePCtoLR) {
135 // This can be simplified: the resulting 32-bit code is 0x48000005
136 MachineInstr *MI = BuildMI(PPC::BL, 1).addImm(1);
137 emitWord(getBinaryCodeForInstr(*MI));
140 emitWord(getBinaryCodeForInstr(*I));
144 unsigned PPC32CodeEmitter::getAddressOfExternalFunction(Function *F) {
145 static std::map<Function*, unsigned> ExternalFn2Addr;
146 std::map<Function*, unsigned>::iterator Addr = ExternalFn2Addr.find(F);
148 // FIXME: this needs to be rewritten.
149 if (Addr == ExternalFn2Addr.end())
150 ExternalFn2Addr[F] = 0; //MCE.forceCompilationOf(F);
151 return ExternalFn2Addr[F];
154 static unsigned enumRegToMachineReg(unsigned enumReg) {
156 case PPC::R0 : case PPC::F0 : return 0;
157 case PPC::R1 : case PPC::F1 : return 1;
158 case PPC::R2 : case PPC::F2 : return 2;
159 case PPC::R3 : case PPC::F3 : return 3;
160 case PPC::R4 : case PPC::F4 : return 4;
161 case PPC::R5 : case PPC::F5 : return 5;
162 case PPC::R6 : case PPC::F6 : return 6;
163 case PPC::R7 : case PPC::F7 : return 7;
164 case PPC::R8 : case PPC::F8 : return 8;
165 case PPC::R9 : case PPC::F9 : return 9;
166 case PPC::R10: case PPC::F10: return 10;
167 case PPC::R11: case PPC::F11: return 11;
168 case PPC::R12: case PPC::F12: return 12;
169 case PPC::R13: case PPC::F13: return 13;
170 case PPC::R14: case PPC::F14: return 14;
171 case PPC::R15: case PPC::F15: return 15;
172 case PPC::R16: case PPC::F16: return 16;
173 case PPC::R17: case PPC::F17: return 17;
174 case PPC::R18: case PPC::F18: return 18;
175 case PPC::R19: case PPC::F19: return 19;
176 case PPC::R20: case PPC::F20: return 20;
177 case PPC::R21: case PPC::F21: return 21;
178 case PPC::R22: case PPC::F22: return 22;
179 case PPC::R23: case PPC::F23: return 23;
180 case PPC::R24: case PPC::F24: return 24;
181 case PPC::R25: case PPC::F25: return 25;
182 case PPC::R26: case PPC::F26: return 26;
183 case PPC::R27: case PPC::F27: return 27;
184 case PPC::R28: case PPC::F28: return 28;
185 case PPC::R29: case PPC::F29: return 29;
186 case PPC::R30: case PPC::F30: return 30;
187 case PPC::R31: case PPC::F31: return 31;
189 std::cerr << "Unhandled reg in enumRegToRealReg!\n";
194 int64_t PPC32CodeEmitter::getMachineOpValue(MachineInstr &MI,
195 MachineOperand &MO) {
196 int64_t rv = 0; // Return value; defaults to 0 for unhandled cases
197 // or things that get fixed up later by the JIT.
198 if (MO.isRegister()) {
199 rv = enumRegToMachineReg(MO.getReg());
200 } else if (MO.isImmediate()) {
201 rv = MO.getImmedValue();
202 } else if (MO.isGlobalAddress()) {
203 //GlobalValue *GV = MO.getGlobal();
204 // FIXME: Emit a relocation here.
206 } else if (MO.isMachineBasicBlock()) {
207 const BasicBlock *BB = MO.getMachineBasicBlock()->getBasicBlock();
208 unsigned* CurrPC = (unsigned*)(intptr_t)MCE.getCurrentPCValue();
209 BBRefs.push_back(std::make_pair(BB, std::make_pair(CurrPC, &MI)));
210 } else if (MO.isConstantPoolIndex()) {
211 unsigned index = MO.getConstantPoolIndex();
212 rv = MCE.getConstantPoolEntryAddress(index);
213 } else if (MO.isFrameIndex()) {
214 std::cerr << "PPC32CodeEmitter: error: Frame index unhandled!\n";
217 std::cerr << "ERROR: Unknown type of MachineOperand: " << MO << "\n";
221 // Special treatment for global symbols: constants and vars
222 if (MO.isConstantPoolIndex() || MO.isGlobalAddress()) {
223 unsigned Opcode = MI.getOpcode();
224 int64_t MBBLoc = BBLocations[MI.getParent()->getBasicBlock()];
225 if (Opcode == PPC::LOADHiAddr) {
226 // LoadHiAddr wants hi16(addr - mbb)
227 rv = (rv - MBBLoc) >> 16;
228 } else if (Opcode == PPC::LWZ || Opcode == PPC::LA ||
229 Opcode == PPC::LFS || Opcode == PPC::LFD) {
230 // These load opcodes want lo16(addr - mbb)
231 rv = (rv - MBBLoc) & 0xffff;
238 void PPC32JITInfo::replaceMachineCodeForFunction (void *Old, void *New) {
239 std::cerr << "PPC32JITInfo::replaceMachineCodeForFunction not implemented\n";
243 #include "PPC32GenCodeEmitter.inc"