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1 /* |
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2 * M68K helper routines |
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3 * |
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4 * Copyright (c) 2007 CodeSourcery |
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5 * |
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6 * This library is free software; you can redistribute it and/or |
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7 * modify it under the terms of the GNU Lesser General Public |
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8 * License as published by the Free Software Foundation; either |
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9 * version 2 of the License, or (at your option) any later version. |
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10 * |
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11 * This library is distributed in the hope that it will be useful, |
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12 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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14 * Lesser General Public License for more details. |
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15 * |
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16 * You should have received a copy of the GNU Lesser General Public |
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17 * License along with this library; if not, write to the Free Software |
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18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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19 */ |
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20 #include "exec.h" |
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21 #include "helpers.h" |
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22 |
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23 #if defined(CONFIG_USER_ONLY) |
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24 |
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25 void do_interrupt(int is_hw) |
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26 { |
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27 env->exception_index = -1; |
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28 } |
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29 |
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30 #else |
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31 |
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32 extern int semihosting_enabled; |
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33 |
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34 #define MMUSUFFIX _mmu |
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35 |
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36 #define SHIFT 0 |
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37 #include "softmmu_template.h" |
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38 |
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39 #define SHIFT 1 |
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40 #include "softmmu_template.h" |
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41 |
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42 #define SHIFT 2 |
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43 #include "softmmu_template.h" |
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44 |
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45 #define SHIFT 3 |
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46 #include "softmmu_template.h" |
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47 |
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48 /* Try to fill the TLB and return an exception if error. If retaddr is |
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49 NULL, it means that the function was called in C code (i.e. not |
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50 from generated code or from helper.c) */ |
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51 /* XXX: fix it to restore all registers */ |
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52 void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr) |
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53 { |
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54 TranslationBlock *tb; |
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55 CPUState *saved_env; |
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56 unsigned long pc; |
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57 int ret; |
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58 |
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59 /* XXX: hack to restore env in all cases, even if not called from |
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60 generated code */ |
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61 saved_env = env; |
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62 env = cpu_single_env; |
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63 ret = cpu_m68k_handle_mmu_fault(env, addr, is_write, mmu_idx, 1); |
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64 if (unlikely(ret)) { |
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65 if (retaddr) { |
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66 /* now we have a real cpu fault */ |
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67 pc = (unsigned long)retaddr; |
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68 tb = tb_find_pc(pc); |
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69 if (tb) { |
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70 /* the PC is inside the translated code. It means that we have |
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71 a virtual CPU fault */ |
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72 cpu_restore_state(tb, env, pc, NULL); |
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73 } |
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74 } |
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75 cpu_loop_exit(); |
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76 } |
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77 env = saved_env; |
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78 } |
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79 |
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80 static void do_rte(void) |
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81 { |
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82 uint32_t sp; |
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83 uint32_t fmt; |
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84 |
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85 sp = env->aregs[7]; |
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86 fmt = ldl_kernel(sp); |
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87 env->pc = ldl_kernel(sp + 4); |
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88 sp |= (fmt >> 28) & 3; |
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89 env->sr = fmt & 0xffff; |
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90 m68k_switch_sp(env); |
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91 env->aregs[7] = sp + 8; |
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92 } |
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93 |
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94 void do_interrupt(int is_hw) |
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95 { |
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96 uint32_t sp; |
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97 uint32_t fmt; |
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98 uint32_t retaddr; |
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99 uint32_t vector; |
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100 |
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101 fmt = 0; |
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102 retaddr = env->pc; |
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103 |
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104 if (!is_hw) { |
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105 switch (env->exception_index) { |
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106 case EXCP_RTE: |
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107 /* Return from an exception. */ |
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108 do_rte(); |
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109 return; |
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110 case EXCP_HALT_INSN: |
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111 if (semihosting_enabled |
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112 && (env->sr & SR_S) != 0 |
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113 && (env->pc & 3) == 0 |
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114 && lduw_code(env->pc - 4) == 0x4e71 |
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115 && ldl_code(env->pc) == 0x4e7bf000) { |
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116 env->pc += 4; |
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117 do_m68k_semihosting(env, env->dregs[0]); |
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118 return; |
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119 } |
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120 env->halted = 1; |
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121 env->exception_index = EXCP_HLT; |
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122 cpu_loop_exit(); |
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123 return; |
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124 } |
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125 if (env->exception_index >= EXCP_TRAP0 |
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126 && env->exception_index <= EXCP_TRAP15) { |
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127 /* Move the PC after the trap instruction. */ |
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128 retaddr += 2; |
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129 } |
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130 } |
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131 |
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132 vector = env->exception_index << 2; |
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133 |
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134 sp = env->aregs[7]; |
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135 |
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136 fmt |= 0x40000000; |
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137 fmt |= (sp & 3) << 28; |
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138 fmt |= vector << 16; |
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139 fmt |= env->sr; |
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140 |
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141 env->sr |= SR_S; |
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142 if (is_hw) { |
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143 env->sr = (env->sr & ~SR_I) | (env->pending_level << SR_I_SHIFT); |
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144 env->sr &= ~SR_M; |
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145 } |
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146 m68k_switch_sp(env); |
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147 |
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148 /* ??? This could cause MMU faults. */ |
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149 sp &= ~3; |
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150 sp -= 4; |
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151 stl_kernel(sp, retaddr); |
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152 sp -= 4; |
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153 stl_kernel(sp, fmt); |
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154 env->aregs[7] = sp; |
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155 /* Jump to vector. */ |
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156 env->pc = ldl_kernel(env->vbr + vector); |
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157 } |
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158 |
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159 #endif |
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160 |
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161 static void raise_exception(int tt) |
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162 { |
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163 env->exception_index = tt; |
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164 cpu_loop_exit(); |
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165 } |
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166 |
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167 void HELPER(raise_exception)(uint32_t tt) |
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168 { |
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169 raise_exception(tt); |
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170 } |
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171 |
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172 void HELPER(divu)(CPUState *env, uint32_t word) |
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173 { |
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174 uint32_t num; |
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175 uint32_t den; |
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176 uint32_t quot; |
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177 uint32_t rem; |
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178 uint32_t flags; |
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179 |
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180 num = env->div1; |
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181 den = env->div2; |
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182 /* ??? This needs to make sure the throwing location is accurate. */ |
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183 if (den == 0) |
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184 raise_exception(EXCP_DIV0); |
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185 quot = num / den; |
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186 rem = num % den; |
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187 flags = 0; |
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188 /* Avoid using a PARAM1 of zero. This breaks dyngen because it uses |
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189 the address of a symbol, and gcc knows symbols can't have address |
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190 zero. */ |
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191 if (word && quot > 0xffff) |
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192 flags |= CCF_V; |
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193 if (quot == 0) |
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194 flags |= CCF_Z; |
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195 else if ((int32_t)quot < 0) |
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196 flags |= CCF_N; |
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197 env->div1 = quot; |
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198 env->div2 = rem; |
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199 env->cc_dest = flags; |
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200 } |
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201 |
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202 void HELPER(divs)(CPUState *env, uint32_t word) |
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203 { |
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204 int32_t num; |
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205 int32_t den; |
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206 int32_t quot; |
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207 int32_t rem; |
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208 int32_t flags; |
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209 |
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210 num = env->div1; |
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211 den = env->div2; |
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212 if (den == 0) |
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213 raise_exception(EXCP_DIV0); |
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214 quot = num / den; |
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215 rem = num % den; |
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216 flags = 0; |
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217 if (word && quot != (int16_t)quot) |
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218 flags |= CCF_V; |
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219 if (quot == 0) |
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220 flags |= CCF_Z; |
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221 else if (quot < 0) |
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222 flags |= CCF_N; |
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223 env->div1 = quot; |
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224 env->div2 = rem; |
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225 env->cc_dest = flags; |
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226 } |