utils/TableGen/FixedLenDecoderEmitter.h

   1 //===------------ FixedLenDecoderEmitter.h - Decoder Generator --*- 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 // It contains the tablegen backend that emits the decoder functions for
  11 // targets with fixed length instruction set.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef FixedLenDECODEREMITTER_H
  16 #define FixedLenDECODEREMITTER_H
  17
  18 #include "CodeGenTarget.h"
  19 #include "TableGenBackend.h"
  20
  21 #include "llvm/Support/DataTypes.h"
  22
  23 namespace llvm {
  24
  25 struct OperandInfo {
  26   unsigned FieldBase;
  27   unsigned FieldLength;
  28   std::string Decoder;
  29
  30   OperandInfo(unsigned FB, unsigned FL, std::string D)
  31     : FieldBase(FB), FieldLength(FL), Decoder(D) { }
  32 };
  33
  34 class FixedLenDecoderEmitter : public TableGenBackend {
  35 public:
  36   FixedLenDecoderEmitter(RecordKeeper &R) :
  37     Records(R), Target(R),
  38     NumberedInstructions(Target.getInstructionsByEnumValue()) {}
  39
  40   // run - Output the code emitter
  41   void run(raw_ostream &o);
  42
  43 private:
  44   RecordKeeper &Records;
  45   CodeGenTarget Target;
  46   std::vector<const CodeGenInstruction*> NumberedInstructions;
  47   std::vector<unsigned> Opcodes;
  48   std::map<unsigned, std::vector<OperandInfo> > Operands;
  49
  50   bool populateInstruction(const CodeGenInstruction &CGI, unsigned Opc);
  51   void populateInstructions();
  52 };
  53
  54 } // end llvm namespace
  55
  56 #endif