lib/Target/ARM/ARMJITInfo.h

   1 //===- ARMJITInfo.h - ARM 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 declaration of the ARMJITInfo class.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef ARMJITINFO_H
  15 #define ARMJITINFO_H
  16
  17 #include "ARMMachineFunctionInfo.h"
  18 #include "llvm/CodeGen/MachineConstantPool.h"
  19 #include "llvm/CodeGen/MachineFunction.h"
  20 #include "llvm/CodeGen/MachineJumpTableInfo.h"
  21 #include "llvm/Target/TargetJITInfo.h"
  22 #include "llvm/ADT/DenseMap.h"
  23 #include "llvm/ADT/SmallVector.h"
  24
  25 namespace llvm {
  26   class ARMTargetMachine;
  27
  28   class ARMJITInfo : public TargetJITInfo {
  29     // ConstPoolId2AddrMap - A map from constant pool ids to the corresponding
  30     // CONSTPOOL_ENTRY addresses.
  31     SmallVector<intptr_t, 16> ConstPoolId2AddrMap;
  32
  33     // JumpTableId2AddrMap - A map from inline jumptable ids to the
  34     // corresponding inline jump table bases.
  35     SmallVector<intptr_t, 16> JumpTableId2AddrMap;
  36
  37     // PCLabelMap - A map from PC labels to addresses.
  38     DenseMap<unsigned, intptr_t> PCLabelMap;
  39
  40     // Sym2IndirectSymMap - A map from symbol (GlobalValue and ExternalSymbol)
  41     // addresses to their indirect symbol addresses.
  42     DenseMap<void*, intptr_t> Sym2IndirectSymMap;
  43
  44     // IsPIC - True if the relocation model is PIC. This is used to determine
  45     // how to codegen function stubs.
  46     bool IsPIC;
  47
  48   public:
  49     explicit ARMJITInfo() : IsPIC(false) { useGOT = false; }
  50
  51     /// replaceMachineCodeForFunction - Make it so that calling the function
  52     /// whose machine code is at OLD turns into a call to NEW, perhaps by
  53     /// overwriting OLD with a branch to NEW.  This is used for self-modifying
  54     /// code.
  55     ///
  56     virtual void replaceMachineCodeForFunction(void *Old, void *New);
  57
  58     /// emitGlobalValueIndirectSym - Use the specified MachineCodeEmitter object
  59     /// to emit an indirect symbol which contains the address of the specified
  60     /// ptr.
  61     virtual void *emitGlobalValueIndirectSym(const GlobalValue* GV, void *ptr,
  62                                             MachineCodeEmitter &MCE);
  63
  64     /// emitFunctionStub - Use the specified MachineCodeEmitter object to emit a
  65     /// small native function that simply calls the function at the specified
  66     /// address.
  67     virtual void *emitFunctionStub(const Function* F, void *Fn,
  68                                    MachineCodeEmitter &MCE);
  69
  70     /// getLazyResolverFunction - Expose the lazy resolver to the JIT.
  71     virtual LazyResolverFn getLazyResolverFunction(JITCompilerFn);
  72
  73     /// relocate - Before the JIT can run a block of code that has been emitted,
  74     /// it must rewrite the code to contain the actual addresses of any
  75     /// referenced global symbols.
  76     virtual void relocate(void *Function, MachineRelocation *MR,
  77                           unsigned NumRelocs, unsigned char* GOTBase);
  78
  79     /// hasCustomConstantPool - Allows a target to specify that constant
  80     /// pool address resolution is handled by the target.
  81     virtual bool hasCustomConstantPool() const { return true; }
  82
  83     /// hasCustomJumpTables - Allows a target to specify that jumptables
  84     /// are emitted by the target.
  85     virtual bool hasCustomJumpTables() const { return true; }
  86
  87     /// allocateSeparateGVMemory - If true, globals should be placed in
  88     /// separately allocated heap memory rather than in the same
  89     /// code memory allocated by MachineCodeEmitter.
  90     virtual bool allocateSeparateGVMemory() const {
  91 #ifdef __APPLE__
  92       return true;
  93 #else
  94       return false;
  95 #endif
  96     }
  97
  98     /// Initialize - Initialize internal stage for the function being JITted.
  99     /// Resize constant pool ids to CONSTPOOL_ENTRY addresses map; resize
 100     /// jump table ids to jump table bases map; remember if codegen relocation
 101     /// model is PIC.
 102     void Initialize(const MachineFunction &MF, bool isPIC) {
 103       const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
 104       ConstPoolId2AddrMap.resize(AFI->getNumConstPoolEntries());
 105       JumpTableId2AddrMap.resize(AFI->getNumJumpTables());
 106       IsPIC = isPIC;
 107     }
 108
 109     /// getConstantPoolEntryAddr - The ARM target puts all constant
 110     /// pool entries into constant islands. This returns the address of the
 111     /// constant pool entry of the specified index.
 112     intptr_t getConstantPoolEntryAddr(unsigned CPI) const {
 113       assert(CPI < ConstPoolId2AddrMap.size());
 114       return ConstPoolId2AddrMap[CPI];
 115     }
 116
 117     /// addConstantPoolEntryAddr - Map a Constant Pool Index to the address
 118     /// where its associated value is stored. When relocations are processed,
 119     /// this value will be used to resolve references to the constant.
 120     void addConstantPoolEntryAddr(unsigned CPI, intptr_t Addr) {
 121       assert(CPI < ConstPoolId2AddrMap.size());
 122       ConstPoolId2AddrMap[CPI] = Addr;
 123     }
 124
 125     /// getJumpTableBaseAddr - The ARM target inline all jump tables within
 126     /// text section of the function. This returns the address of the base of
 127     /// the jump table of the specified index.
 128     intptr_t getJumpTableBaseAddr(unsigned JTI) const {
 129       assert(JTI < JumpTableId2AddrMap.size());
 130       return JumpTableId2AddrMap[JTI];
 131     }
 132
 133     /// addJumpTableBaseAddr - Map a jump table index to the address where
 134     /// the corresponding inline jump table is emitted. When relocations are
 135     /// processed, this value will be used to resolve references to the
 136     /// jump table.
 137     void addJumpTableBaseAddr(unsigned JTI, intptr_t Addr) {
 138       assert(JTI < JumpTableId2AddrMap.size());
 139       JumpTableId2AddrMap[JTI] = Addr;
 140     }
 141
 142     /// getPCLabelAddr - Retrieve the address of the PC label of the specified id.
 143     intptr_t getPCLabelAddr(unsigned Id) const {
 144       DenseMap<unsigned, intptr_t>::const_iterator I = PCLabelMap.find(Id);
 145       assert(I != PCLabelMap.end());
 146       return I->second;
 147     }
 148
 149     /// addPCLabelAddr - Remember the address of the specified PC label.
 150     void addPCLabelAddr(unsigned Id, intptr_t Addr) {
 151       PCLabelMap.insert(std::make_pair(Id, Addr));
 152     }
 153
 154     /// getIndirectSymAddr - Retrieve the address of the indirect symbol of the
 155     /// specified symbol located at address. Returns 0 if the indirect symbol
 156     /// has not been emitted.
 157     intptr_t getIndirectSymAddr(void *Addr) const {
 158       DenseMap<void*,intptr_t>::const_iterator I= Sym2IndirectSymMap.find(Addr);
 159       if (I != Sym2IndirectSymMap.end())
 160         return I->second;
 161       return 0;
 162     }
 163
 164     /// addIndirectSymAddr - Add a mapping from address of an emitted symbol to
 165     /// its indirect symbol address.
 166     void addIndirectSymAddr(void *SymAddr, intptr_t IndSymAddr) {
 167       Sym2IndirectSymMap.insert(std::make_pair(SymAddr, IndSymAddr));
 168     }
 169
 170   private:
 171     /// resolveRelocDestAddr - Resolve the resulting address of the relocation
 172     /// if it's not already solved. Constantpool entries must be resolved by
 173     /// ARM target.
 174     intptr_t resolveRelocDestAddr(MachineRelocation *MR) const;
 175   };
 176 }
 177
 178 #endif