annotate 68kinst.c @ 4:6f6a2d7cc889

Add support for some bit instructions and a few others in the same "category"
author Mike Pavone <pavone@retrodev.com>
date Sun, 04 Nov 2012 23:43:03 -0800
parents a4ad0e3e3e0e
children 85699517043f
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1 #include "68kinst.h"
2
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2 #include <string.h>
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3 #include <stdio.h>
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4
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5 uint32_t sign_extend16(uint32_t val)
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6 {
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7 return (val & 0x8000) ? val | 0xFFFF0000 : val;
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8 }
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9
2
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10 uint32_t sign_extend8(uint32_t val)
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11 {
2
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12 return (val & 0x80) ? val | 0xFFFFFF00 : val;
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13 }
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14
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15 uint16_t *m68k_decode_op_ex(uint16_t *cur, uint8_t mode, uint8_t reg, uint8_t size, m68k_op_info *dst)
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16 {
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17 uint16_t ext;
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18 dst->addr_mode = mode;
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19 switch(mode)
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20 {
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21 case MODE_REG:
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22 case MODE_AREG:
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23 case MODE_AREG_INDIRECT:
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24 case MODE_AREG_POSTINC:
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25 case MODE_AREG_PREDEC:
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26 dst->params.regs.pri = reg;
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27 break;
2
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28 case MODE_AREG_DISPLACE:
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29 ext = *(++cur);
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30 dst->params.regs.pri = reg;
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31 dst->params.regs.displacement = sign_extend16(ext);
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32 break;
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33 case MODE_AREG_INDEX_MEM:
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34 //TODO: implement me
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35 break;
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36 case MODE_PC_INDIRECT_ABS_IMMED:
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37 switch(reg)
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38 {
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39 case 0:
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40 dst->addr_mode = MODE_ABSOLUTE_SHORT;
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41 ext = *(++cur);
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42 dst->params.u32 = sign_extend16(ext);
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43 break;
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44 case 1:
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45 dst->addr_mode = MODE_ABSOLUTE;
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46 ext = *(++cur);
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47 dst->params.u32 = ext << 16 | *(++cur);
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48 break;
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49 case 2:
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50 dst->addr_mode = MODE_PC_DISPLACE;
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51 ext = *(++cur);
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52 dst->params.regs.displacement = sign_extend16(ext);
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53 break;
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54 case 4:
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55 dst->addr_mode = MODE_IMMEDIATE;
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56 ext = *(++cur);
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57 switch (size)
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58 {
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59 case OPSIZE_BYTE:
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60 dst->params.u8 = ext;
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61 break;
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62 case OPSIZE_WORD:
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63 dst->params.u16 = ext;
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64 break;
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65 case OPSIZE_LONG:
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66 dst->params.u32 = ext << 16 | *(++cur);
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67 break;
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68 }
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69 break;
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70 //TODO: implement the rest of these
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71 }
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72 break;
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73 }
2
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74 return cur;
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75 }
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76
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77 uint16_t *m68k_decode_op(uint16_t *cur, uint8_t size, m68k_op_info *dst)
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78 {
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79 uint8_t mode = (*cur >> 3) & 0x7;
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80 uint8_t reg = *cur & 0x7;
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81 return m68k_decode_op_ex(cur, mode, reg, size, dst);
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82 }
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83
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84 void m68k_decode_cond(uint16_t op, m68kinst * decoded)
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85 {
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86 decoded->extra.cond = (op >> 0x8) & 0xF;
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87 }
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88
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89 uint8_t m68K_reg_quick_field(uint16_t op)
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90 {
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91 return (op >> 9) & 0x7;
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92 }
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93
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94 uint16_t * m68K_decode(uint16_t * istream, m68kinst * decoded)
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95 {
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96 uint8_t optype = *istream >> 12;
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97 uint8_t size;
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98 uint8_t reg;
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99 uint8_t opmode;
2
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100 uint32_t immed;
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101 decoded->op = M68K_INVALID;
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102 decoded->src.addr_mode = decoded->dst.addr_mode = MODE_UNUSED;
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103 decoded->variant = VAR_NORMAL;
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104 switch(optype)
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105 {
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106 case BIT_MOVEP_IMMED:
4
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107 if (*istream & 0x100) {
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108 //BTST, BCHG, BCLR, BSET
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109 switch ((*istream >> 6) & 0x3)
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110 {
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111 case 0:
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112 decoded->op = M68K_BTST;
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113 break;
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114 case 1:
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115 decoded->op = M68K_BCHG;
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116 break;
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117 case 2:
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118 decoded->op = M68K_BCLR;
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119 break;
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120 case 3:
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121 decoded->op = M68K_BSET;
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122 break;
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123 }
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124 decoded->src.addr_mode = MODE_REG;
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125 decoded->src.params.regs.pri = m68K_reg_quick_field(*istream);
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126 istream = m68k_decode_op(istream, OPSIZE_LONG, &(decoded->dst));
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127 } else {
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128 switch ((*istream >> 9) & 0x7)
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129 {
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130 case 0:
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131 if ((*istream & 0xFF) == 0x3C) {
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132 decoded->op = M68K_ORI_CCR;
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133 decoded->extra.size = OPSIZE_BYTE;
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134 decoded->src.addr_mode = MODE_IMMEDIATE;
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diff changeset
135 decoded->src.params.u8 = *(++istream);
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
136 } else if((*istream & 0xFF) == 0x7C) {
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
137 decoded->op = M68K_ORI_SR;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
138 decoded->extra.size = OPSIZE_WORD;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
139 decoded->src.addr_mode = MODE_IMMEDIATE;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
140 decoded->src.params.u16 = *(++istream);
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
141 } else {
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
142 //ORI, CMP2.b, CHK2.b
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
143 if ((*istream & 0xC0) != 0xC0) {
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
144 decoded->op = M68K_OR;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
145 decoded->src.addr_mode = MODE_IMMEDIATE;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
146 decoded->extra.size = size = (*istream >> 6) & 3;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
147 reg = *istream & 0x7;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
148 opmode = (*istream >> 3) & 0x7;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
149 switch (size)
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
150 {
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
151 case OPSIZE_BYTE:
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
152 decoded->src.params.u8 = *(++istream);
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
153 break;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
154 case OPSIZE_WORD:
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
155 decoded->src.params.16 = *(++istream);
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
156 break;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
157 case OPSIZE_LONG:
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
158 immed = *(++istream);
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
159 decoded->src.params.u32 = immed << 16 | *(++istream);
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
160 break;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
161 }
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
162 istream = m68k_decode_op_ex(istream, opmode, reg, size, &(decoded->dst));
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
163 } else {
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
164 #ifdef M68020
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
165 //TODO: Implement me for 68020 support
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
166 #endif
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
167 }
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
168 }
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
169 break;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
170 case 1:
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
171 break;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
172 case 2:
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
173 break;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
174 case 3:
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
175 break;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
176 case 4:
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
177 break;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
178 case 5:
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
179 break;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
180 case 6:
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
181 break;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
182 case 7:
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
183 break;
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
184 }
6f6a2d7cc889 Add support for some bit instructions and a few others in the same "category"
Mike Pavone <pavone@retrodev.com>
parents: 3
diff changeset
185 }
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
186 break;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
187 case MOVE_BYTE:
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
188 case MOVE_LONG:
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
189 case MOVE_WORD:
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
190 decoded->op = M68K_MOVE;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
191 decoded->extra.size = optype == MOVE_BYTE ? OPSIZE_BYTE : (optype == MOVE_WORD ? OPSIZE_WORD : OPSIZE_LONG);
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
192 istream = m68k_decode_op(istream, decoded->extra.size, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
193 istream = m68k_decode_op_ex(istream, (*istream >> 6) & 0x7, m68K_reg_quick_field(*istream), decoded->extra.size, &(decoded->dst));
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
194 break;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
195 case MISC:
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
196
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
197 if ((*istream & 0x1C0) == 0x1C0) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
198 decoded->op = M68K_LEA;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
199 decoded->extra.size = OPSIZE_LONG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
200 decoded->dst.addr_mode = MODE_AREG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
201 decoded->dst.params.regs.pri = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
202 istream = m68k_decode_op(istream, decoded->extra.size, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
203 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
204 if (*istream & 0x100) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
205 decoded->op = M68K_CHK;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
206 if ((*istream & 0x180) == 0x180) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
207 decoded->extra.size = OPSIZE_WORD;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
208 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
209 //only on M68020+
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
210 decoded->extra.size = OPSIZE_LONG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
211 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
212 istream = m68k_decode_op(istream, decoded->extra.size, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
213 decoded->dst.addr_mode = MODE_REG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
214 decoded->dst.addr_mode = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
215 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
216 optype = (*istream >> 9) & 0x7;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
217 switch(optype)
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
218 {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
219 case 0:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
220 //Move from SR or NEGX
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
221 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
222 case 1:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
223 //MOVE from CCR or CLR
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
224 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
225 case 2:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
226 //MOVE to CCR or NEG
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
227 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
228 case 3:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
229 //MOVE to SR or NOT
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
230 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
231 case 4:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
232 //EXT, EXTB, LINK.l, NBCD, SWAP, BKPT, PEA, MOVEM
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
233 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
234 case 5:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
235 //BGND, ILLEGAL, TAS, TST
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
236 optype = *istream & 0xFF;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
237 if (optype == 0xFA) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
238 //BGND - CPU32 only
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
239 } else if (optype == 0xFC) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
240 decoded->op = M68K_ILLEGAL;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
241 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
242 size = (*istream & 0xC0) >> 6;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
243 if (size == OPSIZE_INVALID) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
244 decoded->op = M68K_TAS;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
245 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
246 decoded->op = M68K_TST;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
247 decoded->extra.size = size;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
248 istream = m68k_decode_op(istream, decoded->extra.size, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
249 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
250 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
251 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
252 case 6:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
253 //MULU, MULS, DIVU, DIVUL, DIVS, DIVSL, MOVEM
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
254 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
255 case 7:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
256 //TRAP, LINK.w, UNLNK, MOVE USP, RESET, NOP, STOP, RTE, RTD, RTS, TRAPV, RTR, MOVEC, JSR, JMP
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
257 if (*istream & 0x80) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
258 //JSR, JMP
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
259 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
260 //it would appear bit 6 needs to be set for it to be a valid instruction here
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
261 switch((*istream >> 3) & 0x7)
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
262 {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
263 case 0:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
264 case 1:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
265 //TRAP
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
266 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
267 case 2:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
268 //LINK.w
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
269 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
270 case 3:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
271 //UNLNK
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
272 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
273 case 4:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
274 case 5:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
275 //MOVE USP
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
276 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
277 case 6:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
278 switch(*istream & 0x7)
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
279 {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
280 case 0:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
281 decoded->op = M68K_RESET;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
282 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
283 case 1:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
284 decoded->op = M68K_NOP;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
285 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
286 case 2:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
287 decoded->op = M68K_STOP;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
288 decoded->extra.size = OPSIZE_WORD;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
289 decoded->src.addr_mode = MODE_IMMEDIATE;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
290 decoded->src.params.u16 =*(++istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
291 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
292 case 3:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
293 decoded->op = M68K_RTE;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
294 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
295 case 4:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
296 #ifdef M68010
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
297 decoded->op = M68K_RTD;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
298 decoded->extra.size = OPSIZE_WORD;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
299 decoded->src.addr_mode = MODE_IMMEDIATE;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
300 decoded->src.params.u16 =*(++istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
301 #endif
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
302 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
303 case 5:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
304 decoded->op = M68K_RTS;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
305 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
306 case 6:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
307 decoded->op = M68K_TRAPV;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
308 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
309 case 7:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
310 decoded->op = M68K_RTR;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
311 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
312 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
313 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
314 case 7:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
315 //MOVEC
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
316 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
317 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
318 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
319 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
320 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
321 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
322 }
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
323 break;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
324 case QUICK_ARITH_LOOP:
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
325 size = (*istream >> 6) & 3;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
326 if (size == 0x3) {
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
327 //DBcc, TRAPcc or Scc
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
328 m68k_decode_cond(*istream, decoded);
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
329 switch ((*istream >> 3) & 0x7)
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
330 {
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
331 case 1: //DBcc
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
332 decoded->op = M68K_DBCC;
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
333 decoded->src.addr_mode = MODE_IMMEDIATE;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
334 decoded->src.params.u16 = *(++istream);
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
335 decoded->dst.addr_mode = MODE_REG;
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
336 decoded->dst.params.regs.pri = *istream & 0x7;
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
337 break;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
338 case 7: //TRAPcc
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
339 #ifdef M68020
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
340 decoded->op = M68K_TRAPCC;
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
341 decoded->src.addr_mode = MODE_IMMEDIATE;
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
342 //TODO: Figure out what to do with OPMODE and optional extention words
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
343 #endif
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
344 break;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
345 default: //Scc
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
346 decoded->op = M68K_SCC;
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
347 istream = m68k_decode_op(istream, OPSIZE_BYTE, &(decoded->dst));
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
348 break;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
349 }
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
350 } else {
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
351 //ADDQ, SUBQ
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
352 decoded->variant = VAR_QUICK;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
353 decoded->extra.size = size;
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
354 decoded->src.addr_mode = MODE_IMMEDIATE;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
355 istream = m68k_decode_op(istream, size, &(decoded->dst));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
356 immed = m68K_reg_quick_field(*istream);
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
357 if (!immed) {
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
358 immed = 8;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
359 }
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
360 switch (size)
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
361 {
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
362 case OPSIZE_BYTE:
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
363 decoded->src.params.u8 = immed;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
364 break;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
365 case OPSIZE_WORD:
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
366 decoded->src.params.u16 = immed;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
367 break;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
368 case OPSIZE_LONG:
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
369 decoded->src.params.u32 = immed;
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
370 break;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
371 }
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
372 if (*istream & 0x100) {
0
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
373 decoded->op = M68K_SUB;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
374 } else {
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
375 decoded->op = M68K_ADD;
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
376 }
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
377 }
2432d177e1ac Initial work on M68K instruction decoding
Mike Pavone <pavone@retrodev.com>
parents:
diff changeset
378 break;
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
379 case BRANCH:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
380 m68k_decode_cond(*istream, decoded);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
381 decoded->op = decoded->extra.cond == COND_FALSE ? M68K_BSR : M68K_BCC;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
382 decoded->src.addr_mode = MODE_IMMEDIATE;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
383 immed = *istream & 0xFF;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
384 if (immed == 0) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
385 decoded->variant = VAR_WORD;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
386 immed = *(++istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
387 immed = sign_extend16(immed);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
388 } else if (immed == 0xFF) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
389 decoded->variant = VAR_LONG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
390 immed = *(++istream) << 16;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
391 immed |= *(++istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
392 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
393 decoded->variant = VAR_BYTE;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
394 immed = sign_extend8(immed);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
395 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
396 decoded->src.params.u32 = immed;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
397 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
398 case MOVEQ:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
399 decoded->op = M68K_MOVE;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
400 decoded->variant = VAR_QUICK;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
401 decoded->src.addr_mode = MODE_IMMEDIATE;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
402 decoded->src.params.u32 = sign_extend8(*istream & 0xFF);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
403 decoded->dst.addr_mode = MODE_REG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
404 decoded->dst.params.regs.pri = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
405 immed = *istream & 0xFF;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
406 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
407 case OR_DIV_SBCD:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
408 //TODO: Implement me
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
409 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
410 case SUB_SUBX:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
411 size = *istream >> 6 & 0x3;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
412 decoded->op = M68K_SUB;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
413 if (*istream & 0x100) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
414 //<ea> destination, SUBA.l or SUBX
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
415 if (*istream & 0x6) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
416 if (size == OPSIZE_INVALID) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
417 //SUBA.l
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
418 decoded->extra.size = OPSIZE_LONG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
419 decoded->dst.addr_mode = MODE_AREG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
420 istream = m68k_decode_op(istream, OPSIZE_LONG, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
421 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
422 decoded->extra.size = size;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
423 decoded->src.addr_mode = MODE_REG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
424 istream = m68k_decode_op(istream, size, &(decoded->dst));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
425 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
426 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
427 //SUBX
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
428 decoded->op = M68K_SUBX;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
429 decoded->extra.size = size;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
430 istream = m68k_decode_op(istream, size, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
431 decoded->dst.addr_mode = decoded->src.addr_mode;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
432 decoded->dst.params.regs.pri = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
433 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
434 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
435 if (size == OPSIZE_INVALID) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
436 //SUBA.w
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
437 decoded->extra.size = OPSIZE_WORD;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
438 decoded->dst.addr_mode = MODE_AREG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
439 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
440 decoded->extra.size = size;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
441 decoded->dst.addr_mode = MODE_REG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
442 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
443 decoded->dst.params.regs.pri = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
444 istream = m68k_decode_op(istream, decoded->extra.size, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
445 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
446 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
447 case RESERVED:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
448 //TODO: implement me
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
449 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
450 case CMP_XOR:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
451 size = *istream >> 6 & 0x3;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
452 decoded->op = M68K_CMP;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
453 if (*istream & 0x100) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
454 //CMPM or EOR
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
455 istream = m68k_decode_op(istream, size, &(decoded->dst));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
456 if (decoded->src.addr_mode == MODE_AREG) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
457 //CMPM
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
458 decoded->src.addr_mode = decoded->dst.addr_mode = MODE_AREG_POSTINC;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
459 decoded->src.params.regs.pri = decoded->dst.params.regs.pri;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
460 decoded->dst.params.regs.pri = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
461 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
462 //EOR
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
463 decoded->op = M68K_EOR;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
464 decoded->extra.size = size;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
465 decoded->src.addr_mode = MODE_REG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
466 decoded->src.params.regs.pri = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
467 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
468 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
469 //CMP
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
470 decoded->extra.size = size;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
471 decoded->dst.addr_mode = MODE_REG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
472 decoded->dst.params.regs.pri = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
473 istream = m68k_decode_op(istream, size, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
474 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
475 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
476 case AND_MUL_ABCD_EXG:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
477 //page 575 for summary
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
478 //EXG opmodes:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
479 //01000 -data regs
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
480 //01001 -addr regs
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
481 //10001 -one of each
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
482 //AND opmodes:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
483 //operand order bit + 2 size bits (00 - 10)
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
484 //no address register direct addressing
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
485 //data register direct not allowed when <ea> is the source (operand order bit of 1)
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
486 if (*istream & 0x100) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
487 if ((*istream & 0xC0) == 0xC0) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
488 decoded->op = M68K_MULS;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
489 decoded->extra.size = OPSIZE_WORD;
3
a4ad0e3e3e0e Finish mulu.w, muls.w and abcd parameter decoding
Mike Pavone <pavone@retrodev.com>
parents: 2
diff changeset
490 decoded->dst.addr_mode = MODE_REG;
a4ad0e3e3e0e Finish mulu.w, muls.w and abcd parameter decoding
Mike Pavone <pavone@retrodev.com>
parents: 2
diff changeset
491 decoded->dst.params.regs.pri = m68K_reg_quick_field(*istream);
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
492 istream = m68k_decode_op(istream, OPSIZE_WORD, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
493 } else if(!(*istream & 0xF0)) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
494 decoded->op = M68K_ABCD;
3
a4ad0e3e3e0e Finish mulu.w, muls.w and abcd parameter decoding
Mike Pavone <pavone@retrodev.com>
parents: 2
diff changeset
495 decoded->extra.size = OPSIZE_BYTE;
a4ad0e3e3e0e Finish mulu.w, muls.w and abcd parameter decoding
Mike Pavone <pavone@retrodev.com>
parents: 2
diff changeset
496 decoded->src.params.regs.pri = *istream & 0x7;
a4ad0e3e3e0e Finish mulu.w, muls.w and abcd parameter decoding
Mike Pavone <pavone@retrodev.com>
parents: 2
diff changeset
497 decoded->dst.params.regs.pri = m68K_reg_quick_field(*istream);
a4ad0e3e3e0e Finish mulu.w, muls.w and abcd parameter decoding
Mike Pavone <pavone@retrodev.com>
parents: 2
diff changeset
498 decoded->dst.addr_mode = decoded->src.addr_mode = (*istream & 8) ? MODE_AREG_PREDEC : MODE_REG;
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
499 } else if(!(*istream & 0x30)) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
500 decoded->op = M68K_EXG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
501 decoded->extra.size = OPSIZE_LONG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
502 decoded->src.params.regs.pri = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
503 decoded->dst.params.regs.pri = *istream & 0x7;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
504 if (*istream & 0x8) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
505 if (*istream & 0x80) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
506 decoded->src.addr_mode = MODE_REG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
507 decoded->dst.addr_mode = MODE_AREG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
508 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
509 decoded->src.addr_mode = decoded->dst.addr_mode = MODE_AREG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
510 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
511 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
512 decoded->src.addr_mode = decoded->dst.addr_mode = MODE_REG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
513 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
514 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
515 decoded->op = M68K_AND;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
516 decoded->extra.size = (*istream >> 6);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
517 decoded->dst.addr_mode = MODE_REG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
518 decoded->dst.params.regs.pri = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
519 istream = m68k_decode_op(istream, decoded->extra.size, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
520 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
521 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
522 if ((*istream & 0xC0) == 0xC0) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
523 decoded->op = M68K_MULU;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
524 decoded->extra.size = OPSIZE_WORD;
3
a4ad0e3e3e0e Finish mulu.w, muls.w and abcd parameter decoding
Mike Pavone <pavone@retrodev.com>
parents: 2
diff changeset
525 decoded->dst.addr_mode = MODE_REG;
a4ad0e3e3e0e Finish mulu.w, muls.w and abcd parameter decoding
Mike Pavone <pavone@retrodev.com>
parents: 2
diff changeset
526 decoded->dst.params.regs.pri = m68K_reg_quick_field(*istream);
2
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
527 istream = m68k_decode_op(istream, OPSIZE_WORD, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
528 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
529 decoded->op = M68K_AND;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
530 decoded->extra.size = (*istream >> 6);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
531 decoded->src.addr_mode = MODE_REG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
532 decoded->src.params.regs.pri = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
533 istream = m68k_decode_op(istream, decoded->extra.size, &(decoded->dst));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
534 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
535 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
536 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
537 case ADD_ADDX:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
538 size = *istream >> 6 & 0x3;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
539 decoded->op = M68K_ADD;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
540 if (*istream & 0x100) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
541 //<ea> destination, ADDA.l or ADDX
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
542 if (*istream & 0x6) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
543 if (size == OPSIZE_INVALID) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
544 //ADDA.l
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
545 decoded->extra.size = OPSIZE_LONG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
546 decoded->dst.addr_mode = MODE_AREG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
547 istream = m68k_decode_op(istream, OPSIZE_LONG, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
548 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
549 decoded->extra.size = size;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
550 decoded->src.addr_mode = MODE_REG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
551 istream = m68k_decode_op(istream, size, &(decoded->dst));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
552 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
553 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
554 //ADDX
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
555 decoded->op = M68K_ADDX;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
556 //FIXME: Size is not technically correct
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
557 decoded->extra.size = size;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
558 istream = m68k_decode_op(istream, size, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
559 decoded->dst.addr_mode = decoded->src.addr_mode;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
560 decoded->dst.params.regs.pri = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
561 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
562 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
563 if (size == OPSIZE_INVALID) {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
564 //ADDA.w
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
565 decoded->extra.size = OPSIZE_WORD;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
566 decoded->dst.addr_mode = MODE_AREG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
567 } else {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
568 decoded->extra.size = size;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
569 decoded->dst.addr_mode = MODE_REG;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
570 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
571 decoded->dst.params.regs.pri = m68K_reg_quick_field(*istream);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
572 istream = m68k_decode_op(istream, decoded->extra.size, &(decoded->src));
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
573 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
574 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
575 case SHIFT_ROTATE:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
576 //TODO: Implement me
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
577 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
578 case COPROC:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
579 //TODO: Implement me
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
580 break;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
581 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
582 return istream+1;
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
583 }
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
584
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
585 char * mnemonics[] = {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
586 "abcd",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
587 "add",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
588 "addx",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
589 "and",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
590 "andi_ccr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
591 "andi_sr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
592 "asl",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
593 "asr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
594 "bcc",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
595 "bchg",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
596 "bclr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
597 "bset",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
598 "bsr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
599 "btst",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
600 "chk",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
601 "clr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
602 "cmp",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
603 "dbcc",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
604 "divs",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
605 "divu",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
606 "eor",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
607 "eori_ccr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
608 "eori_sr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
609 "exg",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
610 "ext",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
611 "illegal",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
612 "jmp",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
613 "jsr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
614 "lea",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
615 "link",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
616 "lsl",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
617 "lsr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
618 "move",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
619 "move_ccr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
620 "move_from_sr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
621 "move_sr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
622 "move_usp",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
623 "movem",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
624 "movep",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
625 "muls",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
626 "mulu",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
627 "nbcd",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
628 "neg",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
629 "negx",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
630 "nop",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
631 "not",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
632 "or",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
633 "ori_ccr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
634 "ori_sr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
635 "pea",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
636 "reset",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
637 "rol",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
638 "ror",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
639 "roxl",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
640 "roxr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
641 "rte",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
642 "rtr",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
643 "rts",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
644 "sbcd",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
645 "scc",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
646 "stop",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
647 "sub",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
648 "subx",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
649 "swap",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
650 "tas",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
651 "trap",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
652 "trapv",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
653 "tst",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
654 "unlnk",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
655 "invalid"
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
656 };
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
657
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
658 char * cond_mnem[] = {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
659 "ra",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
660 "f",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
661 "hi",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
662 "ls",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
663 "cc",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
664 "cs",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
665 "ne",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
666 "eq",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
667 "vc",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
668 "vs",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
669 "pl",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
670 "mi",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
671 "ge",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
672 "lt",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
673 "gt",
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
674 "le"
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
675 };
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
676
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
677 int m68K_disasm_op(m68k_op_info *decoded, uint8_t size, char *dst, int need_comma)
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
678 {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
679 char * c = need_comma ? "," : "";
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
680 switch(decoded->addr_mode)
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
681 {
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
682 case MODE_REG:
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
Mike Pavone <pavone@retrodev.com>
parents: 0
diff changeset
683 return sprintf(dst, "%s d%d", c, decoded->params.regs.pri);
5df303bf72e6 Improve 68K instruction decoding. Add simple disassembler.
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684 case MODE_AREG:
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685 return sprintf(dst, "%s a%d", c, decoded->params.regs.pri);
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686 case MODE_AREG_INDIRECT:
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687 return sprintf(dst, "%s (a%d)", c, decoded->params.regs.pri);
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688 case MODE_AREG_POSTINC:
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689 return sprintf(dst, "%s (a%d)+", c, decoded->params.regs.pri);
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690 case MODE_AREG_PREDEC:
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691 return sprintf(dst, "%s -(a%d)", c, decoded->params.regs.pri);
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692 case MODE_IMMEDIATE:
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693 return sprintf(dst, "%s #%d", c, size == OPSIZE_LONG ? decoded->params.u32 : (size == OPSIZE_WORD ? decoded->params.u16 : decoded->params.u8));
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694 default:
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695 return 0;
0
2432d177e1ac Initial work on M68K instruction decoding
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696 }
2432d177e1ac Initial work on M68K instruction decoding
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697 }
2
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698
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699 int m68k_disasm(m68kinst * decoded, char * dst)
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700 {
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701 int ret,op1len;
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702 uint8_t size;
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703 if (decoded->op == M68K_BCC || decoded->op == M68K_DBCC || decoded->op == M68K_SCC) {
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704 ret = strlen(mnemonics[decoded->op]) - 2;
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705 memcpy(dst, mnemonics[decoded->op], ret);
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706 dst[ret] = 0;
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707 strcat(dst, cond_mnem[decoded->extra.cond]);
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708 ret = strlen(dst);
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709 size = decoded->op = M68K_BCC ? OPSIZE_LONG : OPSIZE_WORD;
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710 } else if (decoded->op == M68K_BSR) {
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711 size = OPSIZE_LONG;
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712 ret = sprintf(dst, "bsr%s", decoded->variant == VAR_BYTE ? ".s" : "");
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713 } else {
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714 size = decoded->extra.size;
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715 ret = sprintf(dst, "%s%s.%c",
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716 mnemonics[decoded->op],
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717 decoded->variant == VAR_QUICK ? "q" : "",
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718 decoded->extra.size == OPSIZE_BYTE ? 'b' : (size == OPSIZE_WORD ? 'w' : 'l'));
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719 }
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720 op1len = m68K_disasm_op(&(decoded->src), size, dst + ret, 0);
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721 ret += op1len;
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722 ret += m68K_disasm_op(&(decoded->dst), size, dst + ret, op1len);
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723 return ret;
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724 }
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725