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1 //===- X86JITInfo.h - X86 implementation of the JIT interface  --*- 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 contains the X86 implementation of the TargetJITInfo class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef X86JITINFO_H
15 #define X86JITINFO_H
16 
17 #include "llvm/Function.h"
18 #include "llvm/CodeGen/JITCodeEmitter.h"
19 #include "llvm/Target/TargetJITInfo.h"
20 
21 namespace llvm {
22   class X86TargetMachine;
23   class X86Subtarget;
24 
25   class X86JITInfo : public TargetJITInfo {
26     X86TargetMachine &TM;
27     const X86Subtarget *Subtarget;
28     uintptr_t PICBase;
29     char* TLSOffset;
30   public:
31     explicit X86JITInfo(X86TargetMachine &tm);
32 
33     /// replaceMachineCodeForFunction - Make it so that calling the function
34     /// whose machine code is at OLD turns into a call to NEW, perhaps by
35     /// overwriting OLD with a branch to NEW.  This is used for self-modifying
36     /// code.
37     ///
38     virtual void replaceMachineCodeForFunction(void *Old, void *New);
39 
40     /// emitGlobalValueIndirectSym - Use the specified JITCodeEmitter object
41     /// to emit an indirect symbol which contains the address of the specified
42     /// ptr.
43     virtual void *emitGlobalValueIndirectSym(const GlobalValue* GV, void *ptr,
44                                              JITCodeEmitter &JCE);
45 
46     // getStubLayout - Returns the size and alignment of the largest call stub
47     // on X86.
48     virtual StubLayout getStubLayout();
49 
50     /// emitFunctionStub - Use the specified JITCodeEmitter object to emit a
51     /// small native function that simply calls the function at the specified
52     /// address.
53     virtual void *emitFunctionStub(const Function* F, void *Target,
54                                    JITCodeEmitter &JCE);
55 
56     /// getPICJumpTableEntry - Returns the value of the jumptable entry for the
57     /// specific basic block.
58     virtual uintptr_t getPICJumpTableEntry(uintptr_t BB, uintptr_t JTBase);
59 
60     /// getLazyResolverFunction - Expose the lazy resolver to the JIT.
61     virtual LazyResolverFn getLazyResolverFunction(JITCompilerFn);
62 
63     /// relocate - Before the JIT can run a block of code that has been emitted,
64     /// it must rewrite the code to contain the actual addresses of any
65     /// referenced global symbols.
66     virtual void relocate(void *Function, MachineRelocation *MR,
67                           unsigned NumRelocs, unsigned char* GOTBase);
68 
69     /// allocateThreadLocalMemory - Each target has its own way of
70     /// handling thread local variables. This method returns a value only
71     /// meaningful to the target.
72     virtual char* allocateThreadLocalMemory(size_t size);
73 
74     /// setPICBase / getPICBase - Getter / setter of PICBase, used to compute
75     /// PIC jumptable entry.
setPICBase(uintptr_t Base)76     void setPICBase(uintptr_t Base) { PICBase = Base; }
getPICBase()77     uintptr_t getPICBase() const { return PICBase; }
78   };
79 }
80 
81 #endif
82