1 //===-- MipsAsmBackend.h - Mips Asm Backend  ------------------------------===//
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 MipsAsmBackend class.
11 //
12 //===----------------------------------------------------------------------===//
13 //
14 
15 #ifndef LLVM_LIB_TARGET_MIPS_MCTARGETDESC_MIPSASMBACKEND_H
16 #define LLVM_LIB_TARGET_MIPS_MCTARGETDESC_MIPSASMBACKEND_H
17 
18 #include "MCTargetDesc/MipsFixupKinds.h"
19 #include "llvm/ADT/Triple.h"
20 #include "llvm/MC/MCAsmBackend.h"
21 
22 namespace llvm {
23 
24 class MCAssembler;
25 struct MCFixupKindInfo;
26 class Target;
27 class MCObjectWriter;
28 
29 class MipsAsmBackend : public MCAsmBackend {
30   Triple::OSType OSType;
31   bool IsLittle; // Big or little endian
32   bool Is64Bit;  // 32 or 64 bit words
33 
34 public:
MipsAsmBackend(const Target & T,Triple::OSType OSType,bool IsLittle,bool Is64Bit)35   MipsAsmBackend(const Target &T, Triple::OSType OSType, bool IsLittle,
36                  bool Is64Bit)
37       : MCAsmBackend(), OSType(OSType), IsLittle(IsLittle), Is64Bit(Is64Bit) {}
38 
39   MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override;
40 
41   void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
42                   uint64_t Value, bool IsPCRel) const override;
43 
44   bool getFixupKind(StringRef Name, MCFixupKind &MappedKind) const override;
45   const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override;
46 
getNumFixupKinds()47   unsigned getNumFixupKinds() const override {
48     return Mips::NumTargetFixupKinds;
49   }
50 
51   /// @name Target Relaxation Interfaces
52   /// @{
53 
54   /// MayNeedRelaxation - Check whether the given instruction may need
55   /// relaxation.
56   ///
57   /// \param Inst - The instruction to test.
mayNeedRelaxation(const MCInst & Inst)58   bool mayNeedRelaxation(const MCInst &Inst) const override {
59     return false;
60   }
61 
62   /// fixupNeedsRelaxation - Target specific predicate for whether a given
63   /// fixup requires the associated instruction to be relaxed.
fixupNeedsRelaxation(const MCFixup & Fixup,uint64_t Value,const MCRelaxableFragment * DF,const MCAsmLayout & Layout)64    bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
65                              const MCRelaxableFragment *DF,
66                              const MCAsmLayout &Layout) const override {
67     // FIXME.
68     llvm_unreachable("RelaxInstruction() unimplemented");
69     return false;
70   }
71 
72   /// RelaxInstruction - Relax the instruction in the given fragment
73   /// to the next wider instruction.
74   ///
75   /// \param Inst - The instruction to relax, which may be the same
76   /// as the output.
77   /// \param [out] Res On return, the relaxed instruction.
relaxInstruction(const MCInst & Inst,MCInst & Res)78   void relaxInstruction(const MCInst &Inst, MCInst &Res) const override {}
79 
80   /// @}
81 
82   bool writeNopData(uint64_t Count, MCObjectWriter *OW) const override;
83 
84   void processFixupValue(const MCAssembler &Asm, const MCAsmLayout &Layout,
85                          const MCFixup &Fixup, const MCFragment *DF,
86                          const MCValue &Target, uint64_t &Value,
87                          bool &IsResolved) override;
88 
89 }; // class MipsAsmBackend
90 
91 } // namespace
92 
93 #endif
94