1 //===-- PPCCodeEmitter.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 "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/Passes.h"
24 #include "llvm/Support/Debug.h"
28 class PPCCodeEmitter : public MachineFunctionPass {
30 MachineCodeEmitter &MCE;
32 // Tracks which instruction references which BasicBlock
33 std::vector<std::pair<MachineBasicBlock*, unsigned*> > BBRefs;
34 // Tracks where each BasicBlock starts
35 std::map<MachineBasicBlock*, long> BBLocations;
37 /// getMachineOpValue - evaluates the MachineOperand of a given MachineInstr
39 int getMachineOpValue(MachineInstr &MI, MachineOperand &MO);
42 PPCCodeEmitter(TargetMachine &T, MachineCodeEmitter &M)
45 const char *getPassName() const { return "PowerPC Machine Code Emitter"; }
47 /// runOnMachineFunction - emits the given MachineFunction to memory
49 bool runOnMachineFunction(MachineFunction &MF);
51 /// emitBasicBlock - emits the given MachineBasicBlock to memory
53 void emitBasicBlock(MachineBasicBlock &MBB);
55 /// emitWord - write a 32-bit word to memory at the current PC
57 void emitWord(unsigned w) { MCE.emitWord(w); }
59 /// getValueBit - return the particular bit of Val
61 unsigned getValueBit(int64_t Val, unsigned bit) { return (Val >> bit) & 1; }
63 /// getBinaryCodeForInstr - This function, generated by the
64 /// CodeEmitterGenerator using TableGen, produces the binary encoding for
65 /// machine instructions.
67 unsigned getBinaryCodeForInstr(MachineInstr &MI);
71 /// addPassesToEmitMachineCode - Add passes to the specified pass manager to get
72 /// machine code emitted. This uses a MachineCodeEmitter object to handle
73 /// actually outputting the machine code and resolving things like the address
74 /// of functions. This method should returns true if machine code emission is
77 bool PPCTargetMachine::addPassesToEmitMachineCode(FunctionPassManager &PM,
78 MachineCodeEmitter &MCE) {
79 // Machine code emitter pass for PowerPC
80 PM.add(new PPCCodeEmitter(*this, MCE));
81 // Delete machine code for this function after emitting it
82 PM.add(createMachineCodeDeleter());
86 bool PPCCodeEmitter::runOnMachineFunction(MachineFunction &MF) {
87 MCE.startFunction(MF);
88 MCE.emitConstantPool(MF.getConstantPool());
89 for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); BB != E; ++BB)
91 MCE.finishFunction(MF);
93 // Resolve branches to BasicBlocks for the entire function
94 for (unsigned i = 0, e = BBRefs.size(); i != e; ++i) {
95 intptr_t Location = BBLocations[BBRefs[i].first];
96 unsigned *Ref = BBRefs[i].second;
97 DEBUG(std::cerr << "Fixup @ " << (void*)Ref << " to " << (void*)Location
99 unsigned Instr = *Ref;
100 intptr_t BranchTargetDisp = (Location - (intptr_t)Ref) >> 2;
102 switch (Instr >> 26) {
103 default: assert(0 && "Unknown branch user!");
104 case 18: // This is B or BL
105 *Ref |= (BranchTargetDisp & ((1 << 24)-1)) << 2;
107 case 16: // This is BLT,BLE,BEQ,BGE,BGT,BNE, or other bcx instruction
108 *Ref |= (BranchTargetDisp & ((1 << 14)-1)) << 2;
118 void PPCCodeEmitter::emitBasicBlock(MachineBasicBlock &MBB) {
119 assert(!PICEnabled && "CodeEmitter does not support PIC!");
120 BBLocations[&MBB] = MCE.getCurrentPCValue();
121 for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ++I){
122 MachineInstr &MI = *I;
123 unsigned Opcode = MI.getOpcode();
124 switch (MI.getOpcode()) {
126 emitWord(getBinaryCodeForInstr(*I));
128 case PPC::IMPLICIT_DEF_GPR:
129 case PPC::IMPLICIT_DEF_F8:
130 case PPC::IMPLICIT_DEF_F4:
131 break; // pseudo opcode, no side effects
132 case PPC::MovePCtoLR:
133 assert(0 && "CodeEmitter does not support MovePCtoLR instruction");
139 static unsigned enumRegToMachineReg(unsigned enumReg) {
141 case PPC::R0 : case PPC::F0 : case PPC::CR0: return 0;
142 case PPC::R1 : case PPC::F1 : case PPC::CR1: return 1;
143 case PPC::R2 : case PPC::F2 : case PPC::CR2: return 2;
144 case PPC::R3 : case PPC::F3 : case PPC::CR3: return 3;
145 case PPC::R4 : case PPC::F4 : case PPC::CR4: return 4;
146 case PPC::R5 : case PPC::F5 : case PPC::CR5: return 5;
147 case PPC::R6 : case PPC::F6 : case PPC::CR6: return 6;
148 case PPC::R7 : case PPC::F7 : case PPC::CR7: return 7;
149 case PPC::R8 : case PPC::F8 : return 8;
150 case PPC::R9 : case PPC::F9 : return 9;
151 case PPC::R10: case PPC::F10: return 10;
152 case PPC::R11: case PPC::F11: return 11;
153 case PPC::R12: case PPC::F12: return 12;
154 case PPC::R13: case PPC::F13: return 13;
155 case PPC::R14: case PPC::F14: return 14;
156 case PPC::R15: case PPC::F15: return 15;
157 case PPC::R16: case PPC::F16: return 16;
158 case PPC::R17: case PPC::F17: return 17;
159 case PPC::R18: case PPC::F18: return 18;
160 case PPC::R19: case PPC::F19: return 19;
161 case PPC::R20: case PPC::F20: return 20;
162 case PPC::R21: case PPC::F21: return 21;
163 case PPC::R22: case PPC::F22: return 22;
164 case PPC::R23: case PPC::F23: return 23;
165 case PPC::R24: case PPC::F24: return 24;
166 case PPC::R25: case PPC::F25: return 25;
167 case PPC::R26: case PPC::F26: return 26;
168 case PPC::R27: case PPC::F27: return 27;
169 case PPC::R28: case PPC::F28: return 28;
170 case PPC::R29: case PPC::F29: return 29;
171 case PPC::R30: case PPC::F30: return 30;
172 case PPC::R31: case PPC::F31: return 31;
174 std::cerr << "Unhandled reg in enumRegToRealReg!\n";
179 int PPCCodeEmitter::getMachineOpValue(MachineInstr &MI, MachineOperand &MO) {
181 int rv = 0; // Return value; defaults to 0 for unhandled cases
182 // or things that get fixed up later by the JIT.
183 if (MO.isRegister()) {
184 rv = enumRegToMachineReg(MO.getReg());
186 // Special encoding for MTCRF and MFOCRF, which uses a bit mask for the
187 // register, not the register number directly.
188 if ((MI.getOpcode() == PPC::MTCRF || MI.getOpcode() == PPC::MFOCRF) &&
189 (MO.getReg() >= PPC::CR0 && MO.getReg() <= PPC::CR7)) {
192 } else if (MO.isImmediate()) {
193 rv = MO.getImmedValue();
194 } else if (MO.isGlobalAddress() || MO.isExternalSymbol()) {
195 bool isExternal = MO.isExternalSymbol() ||
196 MO.getGlobal()->hasWeakLinkage() ||
197 MO.getGlobal()->isExternal();
199 if (MI.getOpcode() == PPC::BL)
200 Reloc = PPC::reloc_pcrel_bx;
202 switch (MI.getOpcode()) {
203 default: MI.dump(); assert(0 && "Unknown instruction for relocation!");
206 Reloc = PPC::reloc_absolute_ptr_high; // Pointer to stub
208 Reloc = PPC::reloc_absolute_high; // Pointer to symbol
211 assert(!isExternal && "Something in the ISEL changed\n");
212 Reloc = PPC::reloc_absolute_low;
226 Reloc = PPC::reloc_absolute_ptr_low;
228 Reloc = PPC::reloc_absolute_low;
232 if (MO.isGlobalAddress())
233 MCE.addRelocation(MachineRelocation(MCE.getCurrentPCOffset(),
234 Reloc, MO.getGlobal(), 0));
236 MCE.addRelocation(MachineRelocation(MCE.getCurrentPCOffset(),
237 Reloc, MO.getSymbolName(), 0));
238 } else if (MO.isMachineBasicBlock()) {
239 unsigned* CurrPC = (unsigned*)(intptr_t)MCE.getCurrentPCValue();
240 BBRefs.push_back(std::make_pair(MO.getMachineBasicBlock(), CurrPC));
241 } else if (MO.isConstantPoolIndex()) {
242 unsigned index = MO.getConstantPoolIndex();
243 unsigned Opcode = MI.getOpcode();
244 rv = MCE.getConstantPoolEntryAddress(index);
245 if (Opcode == PPC::LIS) {
246 // lis wants hi16(addr)
247 if ((short)rv < 0) rv += 1 << 16;
249 } else if (Opcode == PPC::LWZ || Opcode == PPC::LA ||
250 Opcode == PPC::LFS || Opcode == PPC::LFD) {
251 // These load opcodes want lo16(addr)
254 assert(0 && "Unknown constant pool using instruction!");
257 std::cerr << "ERROR: Unknown type of MachineOperand: " << MO << "\n";
264 #include "PPCGenCodeEmitter.inc"