mips.go raw

   1  // Copyright 2015 The Go Authors. All rights reserved.
   2  // Use of this source code is governed by a BSD-style
   3  // license that can be found in the LICENSE file.
   4  
   5  // This file encapsulates some of the odd characteristics of the
   6  // MIPS (MIPS64) instruction set, to minimize its interaction
   7  // with the core of the assembler.
   8  
   9  package arch
  10  
  11  import (
  12  	"github.com/twitchyliquid64/golang-asm/obj"
  13  	"github.com/twitchyliquid64/golang-asm/obj/mips"
  14  )
  15  
  16  func jumpMIPS(word string) bool {
  17  	switch word {
  18  	case "BEQ", "BFPF", "BFPT", "BGEZ", "BGEZAL", "BGTZ", "BLEZ", "BLTZ", "BLTZAL", "BNE", "JMP", "JAL", "CALL":
  19  		return true
  20  	}
  21  	return false
  22  }
  23  
  24  // IsMIPSCMP reports whether the op (as defined by an mips.A* constant) is
  25  // one of the CMP instructions that require special handling.
  26  func IsMIPSCMP(op obj.As) bool {
  27  	switch op {
  28  	case mips.ACMPEQF, mips.ACMPEQD, mips.ACMPGEF, mips.ACMPGED,
  29  		mips.ACMPGTF, mips.ACMPGTD:
  30  		return true
  31  	}
  32  	return false
  33  }
  34  
  35  // IsMIPSMUL reports whether the op (as defined by an mips.A* constant) is
  36  // one of the MUL/DIV/REM/MADD/MSUB instructions that require special handling.
  37  func IsMIPSMUL(op obj.As) bool {
  38  	switch op {
  39  	case mips.AMUL, mips.AMULU, mips.AMULV, mips.AMULVU,
  40  		mips.ADIV, mips.ADIVU, mips.ADIVV, mips.ADIVVU,
  41  		mips.AREM, mips.AREMU, mips.AREMV, mips.AREMVU,
  42  		mips.AMADD, mips.AMSUB:
  43  		return true
  44  	}
  45  	return false
  46  }
  47  
  48  func mipsRegisterNumber(name string, n int16) (int16, bool) {
  49  	switch name {
  50  	case "F":
  51  		if 0 <= n && n <= 31 {
  52  			return mips.REG_F0 + n, true
  53  		}
  54  	case "FCR":
  55  		if 0 <= n && n <= 31 {
  56  			return mips.REG_FCR0 + n, true
  57  		}
  58  	case "M":
  59  		if 0 <= n && n <= 31 {
  60  			return mips.REG_M0 + n, true
  61  		}
  62  	case "R":
  63  		if 0 <= n && n <= 31 {
  64  			return mips.REG_R0 + n, true
  65  		}
  66  	case "W":
  67  		if 0 <= n && n <= 31 {
  68  			return mips.REG_W0 + n, true
  69  		}
  70  	}
  71  	return 0, false
  72  }
  73