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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  #include "llvm/Support/ValueHandle.h"
20  
21  namespace llvm {
22  
23  class Function;
24  struct JITEvent_EmittedFunctionDetails;
25  class MachineCodeEmitter;
26  class MachineCodeInfo;
27  class TargetJITInfo;
28  class TargetMachine;
29  
30  class JITState {
31  private:
32    FunctionPassManager PM;  // Passes to compile a function
33    Module *M;               // Module used to create the PM
34  
35    /// PendingFunctions - Functions which have not been code generated yet, but
36    /// were called from a function being code generated.
37    std::vector<AssertingVH<Function> > PendingFunctions;
38  
39  public:
JITState(Module * M)40    explicit JITState(Module *M) : PM(M), M(M) {}
41  
getPM(const MutexGuard & L)42    FunctionPassManager &getPM(const MutexGuard &L) {
43      return PM;
44    }
45  
getModule()46    Module *getModule() const { return M; }
getPendingFunctions(const MutexGuard & L)47    std::vector<AssertingVH<Function> > &getPendingFunctions(const MutexGuard &L){
48      return PendingFunctions;
49    }
50  };
51  
52  
53  class JIT : public ExecutionEngine {
54    /// types
55    typedef ValueMap<const BasicBlock *, void *>
56        BasicBlockAddressMapTy;
57    /// data
58    TargetMachine &TM;       // The current target we are compiling to
59    TargetJITInfo &TJI;      // The JITInfo for the target we are compiling to
60    JITCodeEmitter *JCE;     // JCE object
61    std::vector<JITEventListener*> EventListeners;
62  
63    /// AllocateGVsWithCode - Some applications require that global variables and
64    /// code be allocated into the same region of memory, in which case this flag
65    /// should be set to true.  Doing so breaks freeMachineCodeForFunction.
66    bool AllocateGVsWithCode;
67  
68    /// True while the JIT is generating code.  Used to assert against recursive
69    /// entry.
70    bool isAlreadyCodeGenerating;
71  
72    JITState *jitstate;
73  
74    /// BasicBlockAddressMap - A mapping between LLVM basic blocks and their
75    /// actualized version, only filled for basic blocks that have their address
76    /// taken.
77    BasicBlockAddressMapTy BasicBlockAddressMap;
78  
79  
80    JIT(Module *M, TargetMachine &tm, TargetJITInfo &tji,
81        JITMemoryManager *JMM, CodeGenOpt::Level OptLevel,
82        bool AllocateGVsWithCode);
83  public:
84    ~JIT();
85  
Register()86    static void Register() {
87      JITCtor = createJIT;
88    }
89  
90    /// getJITInfo - Return the target JIT information structure.
91    ///
getJITInfo()92    TargetJITInfo &getJITInfo() const { return TJI; }
93  
94    /// create - Create an return a new JIT compiler if there is one available
95    /// for the current target.  Otherwise, return null.
96    ///
97    static ExecutionEngine *create(Module *M,
98                                   std::string *Err,
99                                   JITMemoryManager *JMM,
100                                   CodeGenOpt::Level OptLevel =
101                                     CodeGenOpt::Default,
102                                   bool GVsWithCode = true,
103                                   Reloc::Model RM = Reloc::Default,
104                                   CodeModel::Model CMM = CodeModel::Default) {
105      return ExecutionEngine::createJIT(M, Err, JMM, OptLevel, GVsWithCode,
106                                        RM, CMM);
107    }
108  
109    virtual void addModule(Module *M);
110  
111    /// removeModule - Remove a Module from the list of modules.  Returns true if
112    /// M is found.
113    virtual bool removeModule(Module *M);
114  
115    /// runFunction - Start execution with the specified function and arguments.
116    ///
117    virtual GenericValue runFunction(Function *F,
118                                     const std::vector<GenericValue> &ArgValues);
119  
120    /// getPointerToNamedFunction - This method returns the address of the
121    /// specified function by using the dlsym function call.  As such it is only
122    /// useful for resolving library symbols, not code generated symbols.
123    ///
124    /// If AbortOnFailure is false and no function with the given name is
125    /// found, this function silently returns a null pointer. Otherwise,
126    /// it prints a message to stderr and aborts.
127    ///
128    void *getPointerToNamedFunction(const std::string &Name,
129                                    bool AbortOnFailure = true);
130  
131    // CompilationCallback - Invoked the first time that a call site is found,
132    // which causes lazy compilation of the target function.
133    //
134    static void CompilationCallback();
135  
136    /// getPointerToFunction - This returns the address of the specified function,
137    /// compiling it if necessary.
138    ///
139    void *getPointerToFunction(Function *F);
140  
141    /// addPointerToBasicBlock - Adds address of the specific basic block.
142    void addPointerToBasicBlock(const BasicBlock *BB, void *Addr);
143  
144    /// clearPointerToBasicBlock - Removes address of specific basic block.
145    void clearPointerToBasicBlock(const BasicBlock *BB);
146  
147    /// getPointerToBasicBlock - This returns the address of the specified basic
148    /// block, assuming function is compiled.
149    void *getPointerToBasicBlock(BasicBlock *BB);
150  
151    /// getOrEmitGlobalVariable - Return the address of the specified global
152    /// variable, possibly emitting it to memory if needed.  This is used by the
153    /// Emitter.
154    void *getOrEmitGlobalVariable(const GlobalVariable *GV);
155  
156    /// getPointerToFunctionOrStub - If the specified function has been
157    /// code-gen'd, return a pointer to the function.  If not, compile it, or use
158    /// a stub to implement lazy compilation if available.
159    ///
160    void *getPointerToFunctionOrStub(Function *F);
161  
162    /// recompileAndRelinkFunction - This method is used to force a function
163    /// which has already been compiled, to be compiled again, possibly
164    /// after it has been modified. Then the entry to the old copy is overwritten
165    /// with a branch to the new copy. If there was no old copy, this acts
166    /// just like JIT::getPointerToFunction().
167    ///
168    void *recompileAndRelinkFunction(Function *F);
169  
170    /// freeMachineCodeForFunction - deallocate memory used to code-generate this
171    /// Function.
172    ///
173    void freeMachineCodeForFunction(Function *F);
174  
175    /// addPendingFunction - while jitting non-lazily, a called but non-codegen'd
176    /// function was encountered.  Add it to a pending list to be processed after
177    /// the current function.
178    ///
179    void addPendingFunction(Function *F);
180  
181    /// getCodeEmitter - Return the code emitter this JIT is emitting into.
182    ///
getCodeEmitter()183    JITCodeEmitter *getCodeEmitter() const { return JCE; }
184  
185    static ExecutionEngine *createJIT(Module *M,
186                                      std::string *ErrorStr,
187                                      JITMemoryManager *JMM,
188                                      CodeGenOpt::Level OptLevel,
189                                      bool GVsWithCode,
190                                      TargetMachine *TM);
191  
192    // Run the JIT on F and return information about the generated code
193    void runJITOnFunction(Function *F, MachineCodeInfo *MCI = 0);
194  
195    virtual void RegisterJITEventListener(JITEventListener *L);
196    virtual void UnregisterJITEventListener(JITEventListener *L);
197    /// These functions correspond to the methods on JITEventListener.  They
198    /// iterate over the registered listeners and call the corresponding method on
199    /// each.
200    void NotifyFunctionEmitted(
201        const Function &F, void *Code, size_t Size,
202        const JITEvent_EmittedFunctionDetails &Details);
203    void NotifyFreeingMachineCode(void *OldPtr);
204  
205    BasicBlockAddressMapTy &
getBasicBlockAddressMap(const MutexGuard &)206    getBasicBlockAddressMap(const MutexGuard &) {
207      return BasicBlockAddressMap;
208    }
209  
210  
211  private:
212    static JITCodeEmitter *createEmitter(JIT &J, JITMemoryManager *JMM,
213                                         TargetMachine &tm);
214    void runJITOnFunctionUnlocked(Function *F, const MutexGuard &locked);
215    void updateFunctionStub(Function *F);
216    void jitTheFunction(Function *F, const MutexGuard &locked);
217  
218  protected:
219  
220    /// getMemoryforGV - Allocate memory for a global variable.
221    virtual char* getMemoryForGV(const GlobalVariable* GV);
222  
223  };
224  
225  } // End llvm namespace
226  
227  #endif
228