llvm-6502/lib/Target/Mips/MipsInstrFormats.td
Bruno Cardoso Lopes 972f5896e4 Initial Mips support, here we go! =)
- Modifications from the last patch included
  (issues pointed by Evan Cheng are now fixed).
- Added more MipsI instructions.
- Added more patterns to match branch instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37461 91177308-0d34-0410-b5e6-96231b3b80d8
2007-06-06 07:42:06 +00:00

97 lines
2.7 KiB
C++

//===- MipsRegisterInfo.td - Mips Register defs -----------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Bruno Cardoso Lopes and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
// Describe MIPS instructions format
//
// All the possible Mips fields are:
//
// 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 ops, string asmstr, list<dag> pattern>:
Instruction
{
field bits<32> Inst;
let Namespace = "Mips";
bits<6> opcode;
// Top 5 bits are the 'opcode' field
let Inst{31-26} = opcode;
dag OperandList = ops;
let AsmString = asmstr;
let Pattern = pattern;
}
//===----------------------------------------------------------------------===//
// Format R instruction class in Mips : <|opcode|rs|rt|rd|shamt|funct|>
//===----------------------------------------------------------------------===//
class FR<bits<6> op, bits<6> _funct, dag ops, string asmstr, list<dag> pattern>:
MipsInst<ops, asmstr, pattern>
{
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 ops, string asmstr, list<dag> pattern>:
MipsInst<ops, asmstr, pattern>
{
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 ops, string asmstr, list<dag> pattern>:
MipsInst<ops, asmstr, pattern>
{
bits<26> addr;
let opcode = op;
let Inst{25-0} = addr;
}