MipsCodeEmitter.cpp revision 226633 
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
42using namespace llvm;
43
44STATISTIC(NumEmitted, "Number of machine instructions emitted");
45
46namespace {
47
48class 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
59  void getAnalysisUsage(AnalysisUsage &AU) const {
60    AU.addRequired<MachineModuleInfo> ();
61    MachineFunctionPass::getAnalysisUsage(AU);
62  }
63
64  static char ID;
65
66  public:
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
76    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  };
109}
110
111char MipsCodeEmitter::ID = 0;
112
113bool MipsCodeEmitter::runOnMachineFunction(MachineFunction &MF) {
114  JTI = ((MipsTargetMachine&) MF.getTarget()).getJITInfo();
115  II = ((const MipsTargetMachine&) MF.getTarget()).getInstrInfo();
116  TD = ((const MipsTargetMachine&) MF.getTarget()).getTargetData();
117  Subtarget = &TM.getSubtarget<MipsSubtarget> ();
118  MCPEs = &MF.getConstantPool()->getConstants();
119  MJTEs = 0;
120  if (MF.getJumpTableInfo()) MJTEs = &MF.getJumpTableInfo()->getJumpTables();
121  JTI->Initialize(MF, IsPIC);
122  MCE.setModuleInfo(&getAnalysis<MachineModuleInfo> ());
123
124  do {
125    DEBUG(errs() << "JITTing function '"
126        << MF.getFunction()->getName() << "'\n");
127    MCE.startFunction(MF);
128
129    for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
130        MBB != E; ++MBB){
131      MCE.StartMachineBasicBlock(MBB);
132      for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
133          I != E; ++I)
134        emitInstruction(*I);
135    }
136  } while (MCE.finishFunction(MF));
137
138  return false;
139}
140
141unsigned MipsCodeEmitter::getRelocation(const MachineInstr &MI,
142                                        const MachineOperand &MO) const {
143  // NOTE: This relocations are for static.
144  uint64_t TSFlags = MI.getDesc().TSFlags;
145  uint64_t Form = TSFlags & MipsII::FormMask;
146  if (Form == MipsII::FrmJ)
147    return Mips::reloc_mips_26;
148  if ((Form == MipsII::FrmI || Form == MipsII::FrmFI)
149       && MI.getDesc().isBranch())
150    return Mips::reloc_mips_branch;
151  if (Form == MipsII::FrmI && MI.getOpcode() == Mips::LUi)
152    return Mips::reloc_mips_hi;
153  return Mips::reloc_mips_lo;
154}
155
156/// getMachineOpValue - Return binary encoding of operand. If the machine
157/// operand requires relocation, record the relocation and return zero.
158unsigned MipsCodeEmitter::getMachineOpValue(const MachineInstr &MI,
159                                           const MachineOperand &MO) const {
160  if (MO.isReg())
161    return MipsRegisterInfo::getRegisterNumbering(MO.getReg());
162  else if (MO.isImm())
163    return static_cast<unsigned>(MO.getImm());
164  else if (MO.isGlobal())
165    emitGlobalAddress(MO.getGlobal(), getRelocation(MI, MO), true);
166  else if (MO.isSymbol())
167    emitExternalSymbolAddress(MO.getSymbolName(), getRelocation(MI, MO));
168  else if (MO.isCPI())
169    emitConstPoolAddress(MO.getIndex(), getRelocation(MI, MO));
170  else if (MO.isJTI())
171    emitJumpTableAddress(MO.getIndex(), getRelocation(MI, MO));
172  else if (MO.isMBB())
173    emitMachineBasicBlock(MO.getMBB(), getRelocation(MI, MO));
174  else
175    llvm_unreachable("Unable to encode MachineOperand!");
176  return 0;
177}
178
179void MipsCodeEmitter::emitGlobalAddress(const GlobalValue *GV, unsigned Reloc,
180                                                bool MayNeedFarStub) const {
181  MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc,
182                             const_cast<GlobalValue *>(GV), 0, MayNeedFarStub));
183}
184
185void MipsCodeEmitter::
186emitExternalSymbolAddress(const char *ES, unsigned Reloc) const {
187  MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
188                                                 Reloc, ES, 0, 0, false));
189}
190
191void MipsCodeEmitter::emitConstPoolAddress(unsigned CPI, unsigned Reloc) const {
192  MCE.addRelocation(MachineRelocation::getConstPool(MCE.getCurrentPCOffset(),
193                                                    Reloc, CPI, 0, false));
194}
195
196void MipsCodeEmitter::
197emitJumpTableAddress(unsigned JTIndex, unsigned Reloc) const {
198  MCE.addRelocation(MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(),
199                                                    Reloc, JTIndex, 0, false));
200}
201
202void MipsCodeEmitter::emitMachineBasicBlock(MachineBasicBlock *BB,
203                                           unsigned Reloc) const {
204  MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(),
205                                             Reloc, BB));
206}
207
208void MipsCodeEmitter::emitInstruction(const MachineInstr &MI) {
209  DEBUG(errs() << "JIT: " << (void*)MCE.getCurrentPCValue() << ":\t" << MI);
210
211  MCE.processDebugLoc(MI.getDebugLoc(), true);
212
213  // Skip pseudo instructions.
214  if ((MI.getDesc().TSFlags & MipsII::FormMask) == MipsII::Pseudo)
215    return;
216
217  ++NumEmitted;  // Keep track of the # of mi's emitted
218
219  switch (MI.getOpcode()) {
220  default:
221    emitWordLE(getBinaryCodeForInstr(MI));
222    break;
223  }
224
225  MCE.processDebugLoc(MI.getDebugLoc(), false);
226}
227
228void MipsCodeEmitter::emitWordLE(unsigned Word) {
229  DEBUG(errs() << "  0x";
230        errs().write_hex(Word) << "\n");
231  MCE.emitWordLE(Word);
232}
233
234/// createMipsJITCodeEmitterPass - Return a pass that emits the collected Mips
235/// code to the specified MCE object.
236FunctionPass *llvm::createMipsJITCodeEmitterPass(MipsTargetMachine &TM,
237    JITCodeEmitter &JCE) {
238  return new MipsCodeEmitter(TM, JCE);
239}
240
241unsigned MipsCodeEmitter::getBinaryCodeForInstr(const MachineInstr &MI) const {
242 // this function will be automatically generated by the CodeEmitterGenerator
243 // using TableGen
244 return 0;
245}
246