Home | History | Annotate | Download | only in MCTargetDesc 
      1 #include "MCTargetDesc/MipsMCTargetDesc.h"
      2 #include "llvm/ADT/Twine.h"
      3 #include "llvm/MC/MCAssembler.h"
      4 #include "llvm/MC/MCDirectives.h"
      5 #include "llvm/MC/MCELFObjectWriter.h"
      6 #include "llvm/MC/MCExpr.h"
      7 #include "llvm/MC/MCMachObjectWriter.h"
      8 #include "llvm/MC/MCObjectWriter.h"
      9 #include "llvm/MC/MCSectionELF.h"
     10 #include "llvm/MC/MCSectionMachO.h"
     11 #include "llvm/MC/MCAsmBackend.h"
     12 #include "llvm/MC/MCSubtargetInfo.h"
     13 #include "llvm/Object/MachOFormat.h"
     14 #include "llvm/Support/ELF.h"
     15 #include "llvm/Support/ErrorHandling.h"
     16 #include "llvm/Support/raw_ostream.h"
     17 using namespace llvm;
     18 
     19 namespace {
     20 class MipsELFObjectWriter : public MCELFObjectTargetWriter {
     21 public:
     22   MipsELFObjectWriter(bool is64Bit, Triple::OSType OSType, uint16_t EMachine,
     23                       bool HasRelocationAddend)
     24     : MCELFObjectTargetWriter(is64Bit, OSType, EMachine,
     25                               HasRelocationAddend) {}
     26 };
     27 
     28 class MipsAsmBackend : public MCAsmBackend {
     29 public:
     30   MipsAsmBackend(const Target &T)
     31     : MCAsmBackend() {}
     32 
     33   unsigned getNumFixupKinds() const {
     34     return 1;   //tbd
     35   }
     36 
     37   /// ApplyFixup - Apply the \arg Value for given \arg Fixup into the provided
     38   /// data fragment, at the offset specified by the fixup and following the
     39   /// fixup kind as appropriate.
     40   void ApplyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
     41                   uint64_t Value) const {
     42   }
     43 
     44   /// @name Target Relaxation Interfaces
     45   /// @{
     46 
     47   /// MayNeedRelaxation - Check whether the given instruction may need
     48   /// relaxation.
     49   ///
     50   /// \param Inst - The instruction to test.
     51   bool MayNeedRelaxation(const MCInst &Inst) const {
     52     return false;
     53   }
     54 
     55   /// RelaxInstruction - Relax the instruction in the given fragment to the next
     56   /// wider instruction.
     57   ///
     58   /// \param Inst - The instruction to relax, which may be the same as the
     59   /// output.
     60   /// \parm Res [output] - On return, the relaxed instruction.
     61   void RelaxInstruction(const MCInst &Inst, MCInst &Res) const {
     62   }
     63 
     64   /// @}
     65 
     66   /// WriteNopData - Write an (optimal) nop sequence of Count bytes to the given
     67   /// output. If the target cannot generate such a sequence, it should return an
     68   /// error.
     69   ///
     70   /// \return - True on success.
     71   bool WriteNopData(uint64_t Count, MCObjectWriter *OW) const {
     72     return false;
     73   }
     74 };
     75 
     76 class MipsEB_AsmBackend : public MipsAsmBackend {
     77 public:
     78   Triple::OSType OSType;
     79 
     80   MipsEB_AsmBackend(const Target &T, Triple::OSType _OSType)
     81     : MipsAsmBackend(T), OSType(_OSType) {}
     82 
     83   MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
     84     return createELFObjectWriter(createELFObjectTargetWriter(),
     85                                  OS, /*IsLittleEndian*/ false);
     86   }
     87 
     88   MCELFObjectTargetWriter *createELFObjectTargetWriter() const {
     89     return new MipsELFObjectWriter(false, OSType, ELF::EM_MIPS, false);
     90   }
     91 };
     92 
     93 class MipsEL_AsmBackend : public MipsAsmBackend {
     94 public:
     95   Triple::OSType OSType;
     96 
     97   MipsEL_AsmBackend(const Target &T, Triple::OSType _OSType)
     98     : MipsAsmBackend(T), OSType(_OSType) {}
     99 
    100   MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
    101     return createELFObjectWriter(createELFObjectTargetWriter(),
    102                                  OS, /*IsLittleEndian*/ true);
    103   }
    104 
    105   MCELFObjectTargetWriter *createELFObjectTargetWriter() const {
    106     return new MipsELFObjectWriter(false, OSType, ELF::EM_MIPS, false);
    107   }
    108 };
    109 }
    110 
    111 MCAsmBackend *llvm::createMipsAsmBackend(const Target &T, StringRef TT) {
    112   Triple TheTriple(TT);
    113 
    114   // just return little endian for now
    115   //
    116   return new MipsEL_AsmBackend(T, Triple(TT).getOS());
    117 }
    118