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 "MipsInstrInfo.h"
18 #include "MipsRelocations.h"
19 #include "MipsSubtarget.h"
20 #include "MipsTargetMachine.h"
21 #include "llvm/Constants.h"
22 #include "llvm/DerivedTypes.h"
23 #include "llvm/Function.h"
24 #include "llvm/PassManager.h"
25 #include "llvm/CodeGen/JITCodeEmitter.h"
26 #include "llvm/CodeGen/MachineConstantPool.h"
27 #include "llvm/CodeGen/MachineFunctionPass.h"
28 #include "llvm/CodeGen/MachineInstr.h"
29 #include "llvm/CodeGen/MachineJumpTableInfo.h"
30 #include "llvm/CodeGen/MachineModuleInfo.h"
31 #include "llvm/CodeGen/Passes.h"
32 #include "llvm/ADT/Statistic.h"
33 #include "llvm/Support/Debug.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include "llvm/Support/raw_ostream.h"
36 #ifndef NDEBUG
37 #include <iomanip>
38 #endif
39
40 #include "llvm/CodeGen/MachineOperand.h"
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 TargetData *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),
69 II((const MipsInstrInfo *) tm.getInstrInfo()),
70 TD(tm.getTargetData()), TM(tm), MCE(mce), MCPEs(0), MJTEs(0),
71 IsPIC(TM.getRelocationModel() == Reloc::PIC_) {
72 }
73
74 bool runOnMachineFunction(MachineFunction &MF);
75
getPassName() const76 virtual const char *getPassName() const {
77 return "Mips Machine Code Emitter";
78 }
79
80 /// getBinaryCodeForInstr - This function, generated by the
81 /// CodeEmitterGenerator using TableGen, produces the binary encoding for
82 /// machine instructions.
83 unsigned getBinaryCodeForInstr(const MachineInstr &MI) const;
84
85 void emitInstruction(const MachineInstr &MI);
86
87 private:
88
89 void emitWordLE(unsigned Word);
90
91 /// Routines that handle operands which add machine relocations which are
92 /// fixed up by the relocation stage.
93 void emitGlobalAddress(const GlobalValue *GV, unsigned Reloc,
94 bool MayNeedFarStub) const;
95 void emitExternalSymbolAddress(const char *ES, unsigned Reloc) const;
96 void emitConstPoolAddress(unsigned CPI, unsigned Reloc) const;
97 void emitJumpTableAddress(unsigned JTIndex, unsigned Reloc) const;
98 void emitMachineBasicBlock(MachineBasicBlock *BB, unsigned Reloc) const;
99
100 /// getMachineOpValue - Return binary encoding of operand. If the machine
101 /// operand requires relocation, record the relocation and return zero.
102 unsigned getMachineOpValue(const MachineInstr &MI,
103 const MachineOperand &MO) const;
104
105 unsigned getRelocation(const MachineInstr &MI,
106 const MachineOperand &MO) const;
107
108 unsigned getMemEncoding(const MachineInstr &MI, unsigned OpNo) const;
109 unsigned getSizeExtEncoding(const MachineInstr &MI, unsigned OpNo) const;
110 unsigned getSizeInsEncoding(const MachineInstr &MI, unsigned OpNo) const;
111 };
112 }
113
114 char MipsCodeEmitter::ID = 0;
115
runOnMachineFunction(MachineFunction & MF)116 bool MipsCodeEmitter::runOnMachineFunction(MachineFunction &MF) {
117 JTI = ((MipsTargetMachine&) MF.getTarget()).getJITInfo();
118 II = ((const MipsTargetMachine&) MF.getTarget()).getInstrInfo();
119 TD = ((const MipsTargetMachine&) MF.getTarget()).getTargetData();
120 Subtarget = &TM.getSubtarget<MipsSubtarget> ();
121 MCPEs = &MF.getConstantPool()->getConstants();
122 MJTEs = 0;
123 if (MF.getJumpTableInfo()) MJTEs = &MF.getJumpTableInfo()->getJumpTables();
124 JTI->Initialize(MF, IsPIC);
125 MCE.setModuleInfo(&getAnalysis<MachineModuleInfo> ());
126
127 do {
128 DEBUG(errs() << "JITTing function '"
129 << MF.getFunction()->getName() << "'\n");
130 MCE.startFunction(MF);
131
132 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
133 MBB != E; ++MBB){
134 MCE.StartMachineBasicBlock(MBB);
135 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
136 I != E; ++I)
137 emitInstruction(*I);
138 }
139 } while (MCE.finishFunction(MF));
140
141 return false;
142 }
143
getRelocation(const MachineInstr & MI,const MachineOperand & MO) const144 unsigned MipsCodeEmitter::getRelocation(const MachineInstr &MI,
145 const MachineOperand &MO) const {
146 // NOTE: This relocations are for static.
147 uint64_t TSFlags = MI.getDesc().TSFlags;
148 uint64_t Form = TSFlags & MipsII::FormMask;
149 if (Form == MipsII::FrmJ)
150 return Mips::reloc_mips_26;
151 if ((Form == MipsII::FrmI || Form == MipsII::FrmFI)
152 && MI.getDesc().isBranch())
153 return Mips::reloc_mips_branch;
154 if (Form == MipsII::FrmI && MI.getOpcode() == Mips::LUi)
155 return Mips::reloc_mips_hi;
156 return Mips::reloc_mips_lo;
157 }
158
getMemEncoding(const MachineInstr & MI,unsigned OpNo) const159 unsigned MipsCodeEmitter::getMemEncoding(const MachineInstr &MI,
160 unsigned OpNo) const {
161 // Base register is encoded in bits 20-16, offset is encoded in bits 15-0.
162 assert(MI.getOperand(OpNo).isReg());
163 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo)) << 16;
164 return
165 (getMachineOpValue(MI, MI.getOperand(OpNo+1)) & 0xFFFF) | RegBits;
166 }
167
getSizeExtEncoding(const MachineInstr & MI,unsigned OpNo) const168 unsigned MipsCodeEmitter::getSizeExtEncoding(const MachineInstr &MI,
169 unsigned OpNo) const {
170 // size is encoded as size-1.
171 return getMachineOpValue(MI, MI.getOperand(OpNo)) - 1;
172 }
173
getSizeInsEncoding(const MachineInstr & MI,unsigned OpNo) const174 unsigned MipsCodeEmitter::getSizeInsEncoding(const MachineInstr &MI,
175 unsigned OpNo) const {
176 // size is encoded as pos+size-1.
177 return getMachineOpValue(MI, MI.getOperand(OpNo-1)) +
178 getMachineOpValue(MI, MI.getOperand(OpNo)) - 1;
179 }
180
181 /// getMachineOpValue - Return binary encoding of operand. If the machine
182 /// operand requires relocation, record the relocation and return zero.
getMachineOpValue(const MachineInstr & MI,const MachineOperand & MO) const183 unsigned MipsCodeEmitter::getMachineOpValue(const MachineInstr &MI,
184 const MachineOperand &MO) const {
185 if (MO.isReg())
186 return MipsRegisterInfo::getRegisterNumbering(MO.getReg());
187 else if (MO.isImm())
188 return static_cast<unsigned>(MO.getImm());
189 else if (MO.isGlobal())
190 emitGlobalAddress(MO.getGlobal(), getRelocation(MI, MO), true);
191 else if (MO.isSymbol())
192 emitExternalSymbolAddress(MO.getSymbolName(), getRelocation(MI, MO));
193 else if (MO.isCPI())
194 emitConstPoolAddress(MO.getIndex(), getRelocation(MI, MO));
195 else if (MO.isJTI())
196 emitJumpTableAddress(MO.getIndex(), getRelocation(MI, MO));
197 else if (MO.isMBB())
198 emitMachineBasicBlock(MO.getMBB(), getRelocation(MI, MO));
199 else
200 llvm_unreachable("Unable to encode MachineOperand!");
201 return 0;
202 }
203
emitGlobalAddress(const GlobalValue * GV,unsigned Reloc,bool MayNeedFarStub) const204 void MipsCodeEmitter::emitGlobalAddress(const GlobalValue *GV, unsigned Reloc,
205 bool MayNeedFarStub) const {
206 MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc,
207 const_cast<GlobalValue *>(GV), 0, MayNeedFarStub));
208 }
209
210 void MipsCodeEmitter::
emitExternalSymbolAddress(const char * ES,unsigned Reloc) const211 emitExternalSymbolAddress(const char *ES, unsigned Reloc) const {
212 MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
213 Reloc, ES, 0, 0, false));
214 }
215
emitConstPoolAddress(unsigned CPI,unsigned Reloc) const216 void MipsCodeEmitter::emitConstPoolAddress(unsigned CPI, unsigned Reloc) const {
217 MCE.addRelocation(MachineRelocation::getConstPool(MCE.getCurrentPCOffset(),
218 Reloc, CPI, 0, false));
219 }
220
221 void MipsCodeEmitter::
emitJumpTableAddress(unsigned JTIndex,unsigned Reloc) const222 emitJumpTableAddress(unsigned JTIndex, unsigned Reloc) const {
223 MCE.addRelocation(MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(),
224 Reloc, JTIndex, 0, false));
225 }
226
emitMachineBasicBlock(MachineBasicBlock * BB,unsigned Reloc) const227 void MipsCodeEmitter::emitMachineBasicBlock(MachineBasicBlock *BB,
228 unsigned Reloc) const {
229 MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(),
230 Reloc, BB));
231 }
232
emitInstruction(const MachineInstr & MI)233 void MipsCodeEmitter::emitInstruction(const MachineInstr &MI) {
234 DEBUG(errs() << "JIT: " << (void*)MCE.getCurrentPCValue() << ":\t" << MI);
235
236 MCE.processDebugLoc(MI.getDebugLoc(), true);
237
238 // Skip pseudo instructions.
239 if ((MI.getDesc().TSFlags & MipsII::FormMask) == MipsII::Pseudo)
240 return;
241
242 ++NumEmitted; // Keep track of the # of mi's emitted
243
244 switch (MI.getOpcode()) {
245 default:
246 emitWordLE(getBinaryCodeForInstr(MI));
247 break;
248 }
249
250 MCE.processDebugLoc(MI.getDebugLoc(), false);
251 }
252
emitWordLE(unsigned Word)253 void MipsCodeEmitter::emitWordLE(unsigned Word) {
254 DEBUG(errs() << " 0x";
255 errs().write_hex(Word) << "\n");
256 MCE.emitWordLE(Word);
257 }
258
259 /// createMipsJITCodeEmitterPass - Return a pass that emits the collected Mips
260 /// code to the specified MCE object.
createMipsJITCodeEmitterPass(MipsTargetMachine & TM,JITCodeEmitter & JCE)261 FunctionPass *llvm::createMipsJITCodeEmitterPass(MipsTargetMachine &TM,
262 JITCodeEmitter &JCE) {
263 return new MipsCodeEmitter(TM, JCE);
264 }
265
266 #include "MipsGenCodeEmitter.inc"
267