1 //===-- Mips/MipsCodeEmitter.cpp - Convert Mips Code to Machine Code ------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===---------------------------------------------------------------------===//
9 //
10 // This file contains the pass that transforms the Mips machine instructions
11 // into relocatable machine code.
12 //
13 //===---------------------------------------------------------------------===//
14
15 #define DEBUG_TYPE "jit"
16 #include "Mips.h"
17 #include "MCTargetDesc/MipsBaseInfo.h"
18 #include "MipsInstrInfo.h"
19 #include "MipsRelocations.h"
20 #include "MipsSubtarget.h"
21 #include "MipsTargetMachine.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/CodeGen/JITCodeEmitter.h"
24 #include "llvm/CodeGen/MachineConstantPool.h"
25 #include "llvm/CodeGen/MachineFunctionPass.h"
26 #include "llvm/CodeGen/MachineInstr.h"
27 #include "llvm/CodeGen/MachineJumpTableInfo.h"
28 #include "llvm/CodeGen/MachineInstrBuilder.h"
29 #include "llvm/CodeGen/MachineModuleInfo.h"
30 #include "llvm/CodeGen/MachineOperand.h"
31 #include "llvm/CodeGen/Passes.h"
32 #include "llvm/IR/Constants.h"
33 #include "llvm/IR/DerivedTypes.h"
34 #include "llvm/PassManager.h"
35 #include "llvm/Support/Debug.h"
36 #include "llvm/Support/ErrorHandling.h"
37 #include "llvm/Support/raw_ostream.h"
38 #ifndef NDEBUG
39 #include <iomanip>
40 #endif
41
42 using namespace llvm;
43
44 STATISTIC(NumEmitted, "Number of machine instructions emitted");
45
46 namespace {
47
48 class MipsCodeEmitter : public MachineFunctionPass {
49 MipsJITInfo *JTI;
50 const MipsInstrInfo *II;
51 const DataLayout *TD;
52 const MipsSubtarget *Subtarget;
53 TargetMachine &TM;
54 JITCodeEmitter &MCE;
55 const std::vector<MachineConstantPoolEntry> *MCPEs;
56 const std::vector<MachineJumpTableEntry> *MJTEs;
57 bool IsPIC;
58
getAnalysisUsage(AnalysisUsage & AU) const59 void getAnalysisUsage(AnalysisUsage &AU) const {
60 AU.addRequired<MachineModuleInfo> ();
61 MachineFunctionPass::getAnalysisUsage(AU);
62 }
63
64 static char ID;
65
66 public:
MipsCodeEmitter(TargetMachine & tm,JITCodeEmitter & mce)67 MipsCodeEmitter(TargetMachine &tm, JITCodeEmitter &mce)
68 : MachineFunctionPass(ID), JTI(0), II(0), TD(0),
69 TM(tm), MCE(mce), MCPEs(0), MJTEs(0),
70 IsPIC(TM.getRelocationModel() == Reloc::PIC_) {}
71
72 bool runOnMachineFunction(MachineFunction &MF);
73
getPassName() const74 virtual const char *getPassName() const {
75 return "Mips Machine Code Emitter";
76 }
77
78 /// getBinaryCodeForInstr - This function, generated by the
79 /// CodeEmitterGenerator using TableGen, produces the binary encoding for
80 /// machine instructions.
81 uint64_t getBinaryCodeForInstr(const MachineInstr &MI) const;
82
83 void emitInstruction(MachineBasicBlock::instr_iterator MI,
84 MachineBasicBlock &MBB);
85
86 private:
87
88 void emitWord(unsigned Word);
89
90 /// Routines that handle operands which add machine relocations which are
91 /// fixed up by the relocation stage.
92 void emitGlobalAddress(const GlobalValue *GV, unsigned Reloc,
93 bool MayNeedFarStub) const;
94 void emitExternalSymbolAddress(const char *ES, unsigned Reloc) const;
95 void emitConstPoolAddress(unsigned CPI, unsigned Reloc) const;
96 void emitJumpTableAddress(unsigned JTIndex, unsigned Reloc) const;
97 void emitMachineBasicBlock(MachineBasicBlock *BB, unsigned Reloc) const;
98
99 /// getMachineOpValue - Return binary encoding of operand. If the machine
100 /// operand requires relocation, record the relocation and return zero.
101 unsigned getMachineOpValue(const MachineInstr &MI,
102 const MachineOperand &MO) const;
103
104 unsigned getRelocation(const MachineInstr &MI,
105 const MachineOperand &MO) const;
106
107 unsigned getJumpTargetOpValue(const MachineInstr &MI, unsigned OpNo) const;
108 unsigned getJumpTargetOpValueMM(const MachineInstr &MI, unsigned OpNo) const;
109 unsigned getBranchTargetOpValueMM(const MachineInstr &MI,
110 unsigned OpNo) const;
111
112 unsigned getBranchTargetOpValue(const MachineInstr &MI, unsigned OpNo) const;
113 unsigned getMemEncoding(const MachineInstr &MI, unsigned OpNo) const;
114 unsigned getMemEncodingMMImm12(const MachineInstr &MI, unsigned OpNo) const;
115 unsigned getSizeExtEncoding(const MachineInstr &MI, unsigned OpNo) const;
116 unsigned getSizeInsEncoding(const MachineInstr &MI, unsigned OpNo) const;
117 unsigned getLSAImmEncoding(const MachineInstr &MI, unsigned OpNo) const;
118
119 void emitGlobalAddressUnaligned(const GlobalValue *GV, unsigned Reloc,
120 int Offset) const;
121
122 /// Expand pseudo instructions with accumulator register operands.
123 void expandACCInstr(MachineBasicBlock::instr_iterator MI,
124 MachineBasicBlock &MBB, unsigned Opc) const;
125
126 /// \brief Expand pseudo instruction. Return true if MI was expanded.
127 bool expandPseudos(MachineBasicBlock::instr_iterator &MI,
128 MachineBasicBlock &MBB) const;
129 };
130 }
131
132 char MipsCodeEmitter::ID = 0;
133
runOnMachineFunction(MachineFunction & MF)134 bool MipsCodeEmitter::runOnMachineFunction(MachineFunction &MF) {
135 MipsTargetMachine &Target = static_cast<MipsTargetMachine &>(
136 const_cast<TargetMachine &>(MF.getTarget()));
137
138 JTI = Target.getJITInfo();
139 II = Target.getInstrInfo();
140 TD = Target.getDataLayout();
141 Subtarget = &TM.getSubtarget<MipsSubtarget> ();
142 MCPEs = &MF.getConstantPool()->getConstants();
143 MJTEs = 0;
144 if (MF.getJumpTableInfo()) MJTEs = &MF.getJumpTableInfo()->getJumpTables();
145 JTI->Initialize(MF, IsPIC, Subtarget->isLittle());
146 MCE.setModuleInfo(&getAnalysis<MachineModuleInfo> ());
147
148 do {
149 DEBUG(errs() << "JITTing function '"
150 << MF.getName() << "'\n");
151 MCE.startFunction(MF);
152
153 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
154 MBB != E; ++MBB){
155 MCE.StartMachineBasicBlock(MBB);
156 for (MachineBasicBlock::instr_iterator I = MBB->instr_begin(),
157 E = MBB->instr_end(); I != E;)
158 emitInstruction(*I++, *MBB);
159 }
160 } while (MCE.finishFunction(MF));
161
162 return false;
163 }
164
getRelocation(const MachineInstr & MI,const MachineOperand & MO) const165 unsigned MipsCodeEmitter::getRelocation(const MachineInstr &MI,
166 const MachineOperand &MO) const {
167 // NOTE: This relocations are for static.
168 uint64_t TSFlags = MI.getDesc().TSFlags;
169 uint64_t Form = TSFlags & MipsII::FormMask;
170 if (Form == MipsII::FrmJ)
171 return Mips::reloc_mips_26;
172 if ((Form == MipsII::FrmI || Form == MipsII::FrmFI)
173 && MI.isBranch())
174 return Mips::reloc_mips_pc16;
175 if (Form == MipsII::FrmI && MI.getOpcode() == Mips::LUi)
176 return Mips::reloc_mips_hi;
177 return Mips::reloc_mips_lo;
178 }
179
getJumpTargetOpValue(const MachineInstr & MI,unsigned OpNo) const180 unsigned MipsCodeEmitter::getJumpTargetOpValue(const MachineInstr &MI,
181 unsigned OpNo) const {
182 MachineOperand MO = MI.getOperand(OpNo);
183 if (MO.isGlobal())
184 emitGlobalAddress(MO.getGlobal(), getRelocation(MI, MO), true);
185 else if (MO.isSymbol())
186 emitExternalSymbolAddress(MO.getSymbolName(), getRelocation(MI, MO));
187 else if (MO.isMBB())
188 emitMachineBasicBlock(MO.getMBB(), getRelocation(MI, MO));
189 else
190 llvm_unreachable("Unexpected jump target operand kind.");
191 return 0;
192 }
193
getJumpTargetOpValueMM(const MachineInstr & MI,unsigned OpNo) const194 unsigned MipsCodeEmitter::getJumpTargetOpValueMM(const MachineInstr &MI,
195 unsigned OpNo) const {
196 llvm_unreachable("Unimplemented function.");
197 return 0;
198 }
199
getBranchTargetOpValueMM(const MachineInstr & MI,unsigned OpNo) const200 unsigned MipsCodeEmitter::getBranchTargetOpValueMM(const MachineInstr &MI,
201 unsigned OpNo) const {
202 llvm_unreachable("Unimplemented function.");
203 return 0;
204 }
205
getBranchTargetOpValue(const MachineInstr & MI,unsigned OpNo) const206 unsigned MipsCodeEmitter::getBranchTargetOpValue(const MachineInstr &MI,
207 unsigned OpNo) const {
208 MachineOperand MO = MI.getOperand(OpNo);
209 emitMachineBasicBlock(MO.getMBB(), getRelocation(MI, MO));
210 return 0;
211 }
212
getMemEncoding(const MachineInstr & MI,unsigned OpNo) const213 unsigned MipsCodeEmitter::getMemEncoding(const MachineInstr &MI,
214 unsigned OpNo) const {
215 // Base register is encoded in bits 20-16, offset is encoded in bits 15-0.
216 assert(MI.getOperand(OpNo).isReg());
217 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo)) << 16;
218 return (getMachineOpValue(MI, MI.getOperand(OpNo+1)) & 0xFFFF) | RegBits;
219 }
220
getMemEncodingMMImm12(const MachineInstr & MI,unsigned OpNo) const221 unsigned MipsCodeEmitter::getMemEncodingMMImm12(const MachineInstr &MI,
222 unsigned OpNo) const {
223 llvm_unreachable("Unimplemented function.");
224 return 0;
225 }
226
getSizeExtEncoding(const MachineInstr & MI,unsigned OpNo) const227 unsigned MipsCodeEmitter::getSizeExtEncoding(const MachineInstr &MI,
228 unsigned OpNo) const {
229 // size is encoded as size-1.
230 return getMachineOpValue(MI, MI.getOperand(OpNo)) - 1;
231 }
232
getSizeInsEncoding(const MachineInstr & MI,unsigned OpNo) const233 unsigned MipsCodeEmitter::getSizeInsEncoding(const MachineInstr &MI,
234 unsigned OpNo) const {
235 // size is encoded as pos+size-1.
236 return getMachineOpValue(MI, MI.getOperand(OpNo-1)) +
237 getMachineOpValue(MI, MI.getOperand(OpNo)) - 1;
238 }
239
getLSAImmEncoding(const MachineInstr & MI,unsigned OpNo) const240 unsigned MipsCodeEmitter::getLSAImmEncoding(const MachineInstr &MI,
241 unsigned OpNo) const {
242 llvm_unreachable("Unimplemented function.");
243 return 0;
244 }
245
246 /// getMachineOpValue - Return binary encoding of operand. If the machine
247 /// operand requires relocation, record the relocation and return zero.
getMachineOpValue(const MachineInstr & MI,const MachineOperand & MO) const248 unsigned MipsCodeEmitter::getMachineOpValue(const MachineInstr &MI,
249 const MachineOperand &MO) const {
250 if (MO.isReg())
251 return TM.getRegisterInfo()->getEncodingValue(MO.getReg());
252 else if (MO.isImm())
253 return static_cast<unsigned>(MO.getImm());
254 else if (MO.isGlobal())
255 emitGlobalAddress(MO.getGlobal(), getRelocation(MI, MO), true);
256 else if (MO.isSymbol())
257 emitExternalSymbolAddress(MO.getSymbolName(), getRelocation(MI, MO));
258 else if (MO.isCPI())
259 emitConstPoolAddress(MO.getIndex(), getRelocation(MI, MO));
260 else if (MO.isJTI())
261 emitJumpTableAddress(MO.getIndex(), getRelocation(MI, MO));
262 else if (MO.isMBB())
263 emitMachineBasicBlock(MO.getMBB(), getRelocation(MI, MO));
264 else
265 llvm_unreachable("Unable to encode MachineOperand!");
266 return 0;
267 }
268
emitGlobalAddress(const GlobalValue * GV,unsigned Reloc,bool MayNeedFarStub) const269 void MipsCodeEmitter::emitGlobalAddress(const GlobalValue *GV, unsigned Reloc,
270 bool MayNeedFarStub) const {
271 MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc,
272 const_cast<GlobalValue *>(GV), 0,
273 MayNeedFarStub));
274 }
275
emitGlobalAddressUnaligned(const GlobalValue * GV,unsigned Reloc,int Offset) const276 void MipsCodeEmitter::emitGlobalAddressUnaligned(const GlobalValue *GV,
277 unsigned Reloc, int Offset) const {
278 MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc,
279 const_cast<GlobalValue *>(GV), 0, false));
280 MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset() + Offset,
281 Reloc, const_cast<GlobalValue *>(GV), 0, false));
282 }
283
284 void MipsCodeEmitter::
emitExternalSymbolAddress(const char * ES,unsigned Reloc) const285 emitExternalSymbolAddress(const char *ES, unsigned Reloc) const {
286 MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
287 Reloc, ES, 0, 0));
288 }
289
emitConstPoolAddress(unsigned CPI,unsigned Reloc) const290 void MipsCodeEmitter::emitConstPoolAddress(unsigned CPI, unsigned Reloc) const {
291 MCE.addRelocation(MachineRelocation::getConstPool(MCE.getCurrentPCOffset(),
292 Reloc, CPI, 0, false));
293 }
294
295 void MipsCodeEmitter::
emitJumpTableAddress(unsigned JTIndex,unsigned Reloc) const296 emitJumpTableAddress(unsigned JTIndex, unsigned Reloc) const {
297 MCE.addRelocation(MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(),
298 Reloc, JTIndex, 0, false));
299 }
300
emitMachineBasicBlock(MachineBasicBlock * BB,unsigned Reloc) const301 void MipsCodeEmitter::emitMachineBasicBlock(MachineBasicBlock *BB,
302 unsigned Reloc) const {
303 MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(),
304 Reloc, BB));
305 }
306
emitInstruction(MachineBasicBlock::instr_iterator MI,MachineBasicBlock & MBB)307 void MipsCodeEmitter::emitInstruction(MachineBasicBlock::instr_iterator MI,
308 MachineBasicBlock &MBB) {
309 DEBUG(errs() << "JIT: " << (void*)MCE.getCurrentPCValue() << ":\t" << *MI);
310
311 // Expand pseudo instruction. Skip if MI was not expanded.
312 if (((MI->getDesc().TSFlags & MipsII::FormMask) == MipsII::Pseudo) &&
313 !expandPseudos(MI, MBB))
314 return;
315
316 MCE.processDebugLoc(MI->getDebugLoc(), true);
317
318 emitWord(getBinaryCodeForInstr(*MI));
319 ++NumEmitted; // Keep track of the # of mi's emitted
320
321 MCE.processDebugLoc(MI->getDebugLoc(), false);
322 }
323
emitWord(unsigned Word)324 void MipsCodeEmitter::emitWord(unsigned Word) {
325 DEBUG(errs() << " 0x";
326 errs().write_hex(Word) << "\n");
327 if (Subtarget->isLittle())
328 MCE.emitWordLE(Word);
329 else
330 MCE.emitWordBE(Word);
331 }
332
expandACCInstr(MachineBasicBlock::instr_iterator MI,MachineBasicBlock & MBB,unsigned Opc) const333 void MipsCodeEmitter::expandACCInstr(MachineBasicBlock::instr_iterator MI,
334 MachineBasicBlock &MBB,
335 unsigned Opc) const {
336 // Expand "pseudomult $ac0, $t0, $t1" to "mult $t0, $t1".
337 BuildMI(MBB, &*MI, MI->getDebugLoc(), II->get(Opc))
338 .addReg(MI->getOperand(1).getReg()).addReg(MI->getOperand(2).getReg());
339 }
340
expandPseudos(MachineBasicBlock::instr_iterator & MI,MachineBasicBlock & MBB) const341 bool MipsCodeEmitter::expandPseudos(MachineBasicBlock::instr_iterator &MI,
342 MachineBasicBlock &MBB) const {
343 switch (MI->getOpcode()) {
344 case Mips::NOP:
345 BuildMI(MBB, &*MI, MI->getDebugLoc(), II->get(Mips::SLL), Mips::ZERO)
346 .addReg(Mips::ZERO).addImm(0);
347 break;
348 case Mips::B:
349 BuildMI(MBB, &*MI, MI->getDebugLoc(), II->get(Mips::BEQ)).addReg(Mips::ZERO)
350 .addReg(Mips::ZERO).addOperand(MI->getOperand(0));
351 break;
352 case Mips::TRAP:
353 BuildMI(MBB, &*MI, MI->getDebugLoc(), II->get(Mips::BREAK)).addImm(0)
354 .addImm(0);
355 break;
356 case Mips::JALRPseudo:
357 BuildMI(MBB, &*MI, MI->getDebugLoc(), II->get(Mips::JALR), Mips::RA)
358 .addReg(MI->getOperand(0).getReg());
359 break;
360 case Mips::PseudoMULT:
361 expandACCInstr(MI, MBB, Mips::MULT);
362 break;
363 case Mips::PseudoMULTu:
364 expandACCInstr(MI, MBB, Mips::MULTu);
365 break;
366 case Mips::PseudoSDIV:
367 expandACCInstr(MI, MBB, Mips::SDIV);
368 break;
369 case Mips::PseudoUDIV:
370 expandACCInstr(MI, MBB, Mips::UDIV);
371 break;
372 case Mips::PseudoMADD:
373 expandACCInstr(MI, MBB, Mips::MADD);
374 break;
375 case Mips::PseudoMADDU:
376 expandACCInstr(MI, MBB, Mips::MADDU);
377 break;
378 case Mips::PseudoMSUB:
379 expandACCInstr(MI, MBB, Mips::MSUB);
380 break;
381 case Mips::PseudoMSUBU:
382 expandACCInstr(MI, MBB, Mips::MSUBU);
383 break;
384 default:
385 return false;
386 }
387
388 (MI--)->eraseFromBundle();
389 return true;
390 }
391
392 /// createMipsJITCodeEmitterPass - Return a pass that emits the collected Mips
393 /// code to the specified MCE object.
createMipsJITCodeEmitterPass(MipsTargetMachine & TM,JITCodeEmitter & JCE)394 FunctionPass *llvm::createMipsJITCodeEmitterPass(MipsTargetMachine &TM,
395 JITCodeEmitter &JCE) {
396 return new MipsCodeEmitter(TM, JCE);
397 }
398
399 #include "MipsGenCodeEmitter.inc"
400