1 //===-- llvm/MC/MCCodeEmitter.h - Instruction Encoding ----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_MC_MCCODEEMITTER_H
11 #define LLVM_MC_MCCODEEMITTER_H
13 #include "llvm/MC/MCFixup.h"
21 template<typename T> class SmallVectorImpl;
23 /// MCFixupKindInfo - Target independent information on a fixup kind.
24 struct MCFixupKindInfo {
26 /// Is this fixup kind PCrelative. This is used by the assembler backend to
27 /// evaluate fixup values in a target independent manner when possible.
28 FKF_IsPCRel = (1 << 0)
31 /// A target specific name for the fixup kind. The names will be unique for
32 /// distinct kinds on any given target.
35 /// The bit offset to write the relocation into.
37 // FIXME: These two fields are under-specified and not general enough, but it
38 // is covers many things, and is enough to let the AsmStreamer pretty-print
40 unsigned TargetOffset;
42 /// The number of bits written by this fixup. The bits are assumed to be
46 /// Flags describing additional information on this fixup kind.
50 /// MCCodeEmitter - Generic instruction encoding interface.
53 MCCodeEmitter(const MCCodeEmitter &); // DO NOT IMPLEMENT
54 void operator=(const MCCodeEmitter &); // DO NOT IMPLEMENT
55 protected: // Can only create subclasses.
59 virtual ~MCCodeEmitter();
61 /// @name Target Independent Fixup Information
64 /// getNumFixupKinds - Get the number of target specific fixup kinds.
65 virtual unsigned getNumFixupKinds() const = 0;
67 /// getFixupKindInfo - Get information on a fixup kind.
68 virtual const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const;
72 /// EncodeInstruction - Encode the given \arg Inst to bytes on the output
74 virtual void EncodeInstruction(const MCInst &Inst, raw_ostream &OS,
75 SmallVectorImpl<MCFixup> &Fixups) const = 0;
78 } // End llvm namespace