llvm-6502/lib/Target/PIC16/PIC16InstrFormats.td

//===- PIC16InstrFormats.td - PIC16 Instruction Formats-------*- tblgen -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source 
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

//===----------------------------------------------------------------------===//
//  Describe PIC16 instructions format
//
//  All the possible PIC16 fields are:
//
//  opcode  - operation code.
//  f       - 7-bit register file address.
//  d       - 1-bit direction specifier
//  k       - 8/11 bit literals
//  b       - 3 bits bit num specifier
//
//===----------------------------------------------------------------------===//

// Generic PIC16 Format
// PIC16 Instructions are 14-bit wide.

// FIXME: Add Cooper Specific Formats if any.

class PIC16Inst<dag outs, dag ins, string asmstr, list<dag> pattern>
  : Instruction {
  field bits<14> Inst;

  let Namespace = "PIC16";
  dag OutOperandList = outs;
  dag InOperandList = ins;
  let AsmString = asmstr;
  let Pattern = pattern;
}


//===----------------------------------------------------------------------===//
// Byte Oriented instruction class in PIC16 : <|opcode|d|f|>
// opcode = 6 bits.
// d = direction = 1 bit.
// f = file register address = 7 bits.
//===----------------------------------------------------------------------===//

class ByteFormat<bits<6> opcode, dag outs, dag ins, string asmstr,
                 list<dag> pattern>
  :PIC16Inst<outs, ins, asmstr, pattern> {
  bits<1>  d;
  bits<7>  f;

  let Inst{13-8} = opcode;

  let Inst{7} = d;
  let Inst{6-0} = f; 
}

//===----------------------------------------------------------------------===//
// Bit Oriented instruction class in PIC16 : <|opcode|b|f|>
// opcode = 4 bits.
// b = bit specifier = 3 bits.
// f = file register address = 7 bits.
//===----------------------------------------------------------------------===//

class BitFormat<bits<4> opcode, dag outs, dag ins, string asmstr, 
                list<dag> pattern>
  : PIC16Inst<outs, ins, asmstr, pattern> {
  bits<3>  b;
  bits<7>  f;

  let Inst{13-10} = opcode;

  let Inst{9-7} = b;
  let Inst{6-0} = f; 
}

//===----------------------------------------------------------------------===//
// Literal Format instruction class in PIC16 : <|opcode|k|>
// opcode = 6 bits
// k = literal = 8 bits
//===----------------------------------------------------------------------===//

class LiteralFormat<bits<6> opcode, dag outs, dag ins, string asmstr, 
                    list<dag> pattern>
  : PIC16Inst<outs, ins, asmstr, pattern> {
  bits<8> k;
  
  let Inst{13-8} = opcode;

  let Inst{7-0} = k; 
}

//===----------------------------------------------------------------------===//
// Control Format instruction class in PIC16 : <|opcode|k|>
// opcode = 3 bits.
// k = jump address = 11 bits.
//===----------------------------------------------------------------------===//

class ControlFormat<bits<3> opcode, dag outs, dag ins, string asmstr, 
                    list<dag> pattern>
  : PIC16Inst<outs, ins, asmstr, pattern> {
  bits<11> k;

  let Inst{13-11} = opcode;

  let Inst{10-0} = k; 
}

//===----------------------------------------------------------------------===//
// Pseudo instruction class in PIC16
//===----------------------------------------------------------------------===//

class Pseudo<dag outs, dag ins, string asmstr, list<dag> pattern>
  : PIC16Inst<outs, ins, asmstr, pattern> {
   let Inst{13-6} = 0;
}