llvm-6502/lib/Target/Mips/MipsInstrFormats.td
2010-08-17 16:20:04 +00:00

183 lines
5.3 KiB
TableGen

//===- MipsRegisterInfo.td - Mips Register defs ------------*- tablegen -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
// Describe MIPS instructions format
//
// CPU INSTRUCTION FORMATS
//
// opcode - operation code.
// rs - src reg.
// rt - dst reg (on a 2 regs instr) or src reg (on a 3 reg instr).
// rd - dst reg, only used on 3 regs instr.
// shamt - only used on shift instructions, contains the shift amount.
// funct - combined with opcode field give us an operation code.
//
//===----------------------------------------------------------------------===//
// Generic Mips Format
class MipsInst<dag outs, dag ins, string asmstr, list<dag> pattern,
InstrItinClass itin>: Instruction
{
field bits<32> Inst;
let Namespace = "Mips";
bits<6> opcode;
// Top 5 bits are the 'opcode' field
let Inst{31-26} = opcode;
dag OutOperandList = outs;
dag InOperandList = ins;
let AsmString = asmstr;
let Pattern = pattern;
let Itinerary = itin;
}
// Mips Pseudo Instructions Format
class MipsPseudo<dag outs, dag ins, string asmstr, list<dag> pattern>:
MipsInst<outs, ins, asmstr, pattern, IIPseudo>;
//===----------------------------------------------------------------------===//
// Format R instruction class in Mips : <|opcode|rs|rt|rd|shamt|funct|>
//===----------------------------------------------------------------------===//
class FR<bits<6> op, bits<6> _funct, dag outs, dag ins, string asmstr,
list<dag> pattern, InstrItinClass itin>:
MipsInst<outs, ins, asmstr, pattern, itin>
{
bits<5> rd;
bits<5> rs;
bits<5> rt;
bits<5> shamt;
bits<6> funct;
let opcode = op;
let funct = _funct;
let Inst{25-21} = rs;
let Inst{20-16} = rt;
let Inst{15-11} = rd;
let Inst{10-6} = shamt;
let Inst{5-0} = funct;
}
//===----------------------------------------------------------------------===//
// Format I instruction class in Mips : <|opcode|rs|rt|immediate|>
//===----------------------------------------------------------------------===//
class FI<bits<6> op, dag outs, dag ins, string asmstr, list<dag> pattern,
InstrItinClass itin>: MipsInst<outs, ins, asmstr, pattern, itin>
{
bits<5> rt;
bits<5> rs;
bits<16> imm16;
let opcode = op;
let Inst{25-21} = rs;
let Inst{20-16} = rt;
let Inst{15-0} = imm16;
}
//===----------------------------------------------------------------------===//
// Format J instruction class in Mips : <|opcode|address|>
//===----------------------------------------------------------------------===//
class FJ<bits<6> op, dag outs, dag ins, string asmstr, list<dag> pattern,
InstrItinClass itin>: MipsInst<outs, ins, asmstr, pattern, itin>
{
bits<26> addr;
let opcode = op;
let Inst{25-0} = addr;
}
//===----------------------------------------------------------------------===//
//
// FLOATING POINT INSTRUCTION FORMATS
//
// opcode - operation code.
// fs - src reg.
// ft - dst reg (on a 2 regs instr) or src reg (on a 3 reg instr).
// fd - dst reg, only used on 3 regs instr.
// fmt - double or single precision.
// funct - combined with opcode field give us an operation code.
//
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
// Format FR instruction class in Mips : <|opcode|fmt|ft|fs|fd|funct|>
//===----------------------------------------------------------------------===//
class FFR<bits<6> op, bits<6> _funct, bits<5> _fmt, dag outs, dag ins,
string asmstr, list<dag> pattern> :
MipsInst<outs, ins, asmstr, pattern, NoItinerary>
{
bits<5> fd;
bits<5> fs;
bits<5> ft;
bits<5> fmt;
bits<6> funct;
let opcode = op;
let funct = _funct;
let fmt = _fmt;
let Inst{25-21} = fmt;
let Inst{20-16} = ft;
let Inst{15-11} = fs;
let Inst{10-6} = fd;
let Inst{5-0} = funct;
}
//===----------------------------------------------------------------------===//
// Format FI instruction class in Mips : <|opcode|base|ft|immediate|>
//===----------------------------------------------------------------------===//
class FFI<bits<6> op, dag outs, dag ins, string asmstr, list<dag> pattern>:
MipsInst<outs, ins, asmstr, pattern, NoItinerary>
{
bits<5> ft;
bits<5> base;
bits<16> imm16;
let opcode = op;
let Inst{25-21} = base;
let Inst{20-16} = ft;
let Inst{15-0} = imm16;
}
//===----------------------------------------------------------------------===//
// Compare instruction class in Mips : <|010001|fmt|ft|fs|0000011|condcode|>
//===----------------------------------------------------------------------===//
class FCC<bits<5> _fmt, dag outs, dag ins, string asmstr, list<dag> pattern> :
MipsInst<outs, ins, asmstr, pattern, NoItinerary>
{
bits<5> fs;
bits<5> ft;
bits<4> cc;
bits<5> fmt;
let opcode = 0x11;
let fmt = _fmt;
let Inst{25-21} = fmt;
let Inst{20-16} = ft;
let Inst{15-11} = fs;
let Inst{10-6} = 0;
let Inst{5-4} = 0b11;
let Inst{3-0} = cc;
}