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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::JITDefault) {
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