JIT.h revision 502f20b17ede40de84503010b7699b328a4f2867 
1//===-- JIT.h - Class definition for the JIT --------------------*- C++ -*-===//
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 defines the top-level JIT data structure.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef JIT_H
15#define JIT_H
16
17#include "llvm/ExecutionEngine/ExecutionEngine.h"
18#include "llvm/PassManager.h"
19
20namespace llvm {
21
22class Function;
23class GlobalValue;
24class Constant;
25class TargetMachine;
26class TargetJITInfo;
27class MachineCodeEmitter;
28
29class JITState {
30private:
31  FunctionPassManager PM;  // Passes to compile a function
32
33  /// PendingGlobals - Global variables which have had memory allocated for them
34  /// while a function was code generated, but which have not been initialized
35  /// yet.
36  std::vector<const GlobalVariable*> PendingGlobals;
37
38public:
39  explicit JITState(ModuleProvider *MP) : PM(MP) {}
40
41  FunctionPassManager &getPM(const MutexGuard &L) {
42    return PM;
43  }
44
45  std::vector<const GlobalVariable*> &getPendingGlobals(const MutexGuard &L) {
46    return PendingGlobals;
47  }
48};
49
50
51class JIT : public ExecutionEngine {
52  TargetMachine &TM;       // The current target we are compiling to
53  TargetJITInfo &TJI;      // The JITInfo for the target we are compiling to
54  MachineCodeEmitter *MCE; // MCE object
55
56  JITState *jitstate;
57
58  JIT(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji,
59      JITMemoryManager *JMM, bool Fast);
60public:
61  ~JIT();
62
63  static void Register() {
64    JITCtor = create;
65  }
66
67  /// getJITInfo - Return the target JIT information structure.
68  ///
69  TargetJITInfo &getJITInfo() const { return TJI; }
70
71  /// create - Create an return a new JIT compiler if there is one available
72  /// for the current target.  Otherwise, return null.
73  ///
74  static ExecutionEngine *create(ModuleProvider *MP, std::string *Err,
75                                 bool Fast = false) {
76    return createJIT(MP, Err, 0, Fast);
77  }
78
79  virtual void addModuleProvider(ModuleProvider *MP);
80  virtual Module *removeModuleProvider(ModuleProvider *MP,
81                                       std::string *ErrInfo = 0);
82
83  /// runFunction - Start execution with the specified function and arguments.
84  ///
85  virtual GenericValue runFunction(Function *F,
86                                   const std::vector<GenericValue> &ArgValues);
87
88  /// getPointerToNamedFunction - This method returns the address of the
89  /// specified function by using the dlsym function call.  As such it is only
90  /// useful for resolving library symbols, not code generated symbols.
91  ///
92  void *getPointerToNamedFunction(const std::string &Name);
93
94  // CompilationCallback - Invoked the first time that a call site is found,
95  // which causes lazy compilation of the target function.
96  //
97  static void CompilationCallback();
98
99  /// getPointerToFunction - This returns the address of the specified function,
100  /// compiling it if necessary.
101  ///
102  void *getPointerToFunction(Function *F);
103
104  /// getOrEmitGlobalVariable - Return the address of the specified global
105  /// variable, possibly emitting it to memory if needed.  This is used by the
106  /// Emitter.
107  void *getOrEmitGlobalVariable(const GlobalVariable *GV);
108
109  /// getPointerToFunctionOrStub - If the specified function has been
110  /// code-gen'd, return a pointer to the function.  If not, compile it, or use
111  /// a stub to implement lazy compilation if available.
112  ///
113  void *getPointerToFunctionOrStub(Function *F);
114
115  /// recompileAndRelinkFunction - This method is used to force a function
116  /// which has already been compiled, to be compiled again, possibly
117  /// after it has been modified. Then the entry to the old copy is overwritten
118  /// with a branch to the new copy. If there was no old copy, this acts
119  /// just like JIT::getPointerToFunction().
120  ///
121  void *recompileAndRelinkFunction(Function *F);
122
123  /// freeMachineCodeForFunction - deallocate memory used to code-generate this
124  /// Function.
125  ///
126  void freeMachineCodeForFunction(Function *F);
127
128  /// getCodeEmitter - Return the code emitter this JIT is emitting into.
129  MachineCodeEmitter *getCodeEmitter() const { return MCE; }
130
131  static ExecutionEngine *createJIT(ModuleProvider *MP, std::string *Err,
132                                    JITMemoryManager *JMM, bool Fast);
133
134private:
135  static MachineCodeEmitter *createEmitter(JIT &J, JITMemoryManager *JMM);
136  void runJITOnFunction (Function *F);
137};
138
139} // End llvm namespace
140
141#endif
142