target-unicore32/op_helper.c

   1 /*
   2  *  UniCore32 helper routines
   3  *
   4  * Copyright (C) 2010-2011 GUAN Xue-tao
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation, or (at your option) any
   9  * later version. See the COPYING file in the top-level directory.
  10  */
  11 #include "cpu.h"
  12 #include "dyngen-exec.h"
  13 #include "helper.h"
  14
  15 #define SIGNBIT (uint32_t)0x80000000
  16 #define SIGNBIT64 ((uint64_t)1 << 63)
  17
  18 void HELPER(exception)(uint32_t excp)
  19 {
  20     env->exception_index = excp;
  21     cpu_loop_exit(env);
  22 }
  23
  24 static target_ulong asr_read(void)
  25 {
  26     int ZF;
  27     ZF = (env->ZF == 0);
  28     return env->uncached_asr | (env->NF & 0x80000000) | (ZF << 30) |
  29         (env->CF << 29) | ((env->VF & 0x80000000) >> 3);
  30 }
  31
  32 target_ulong cpu_asr_read(CPUUniCore32State *env1)
  33 {
  34     CPUUniCore32State *saved_env;
  35     target_ulong ret;
  36
  37     saved_env = env;
  38     env = env1;
  39     ret = asr_read();
  40     env = saved_env;
  41     return ret;
  42 }
  43
  44 target_ulong HELPER(asr_read)(void)
  45 {
  46     return asr_read();
  47 }
  48
  49 static void asr_write(target_ulong val, target_ulong mask)
  50 {
  51     if (mask & ASR_NZCV) {
  52         env->ZF = (~val) & ASR_Z;
  53         env->NF = val;
  54         env->CF = (val >> 29) & 1;
  55         env->VF = (val << 3) & 0x80000000;
  56     }
  57
  58     if ((env->uncached_asr ^ val) & mask & ASR_M) {
  59         switch_mode(env, val & ASR_M);
  60     }
  61     mask &= ~ASR_NZCV;
  62     env->uncached_asr = (env->uncached_asr & ~mask) | (val & mask);
  63 }
  64
  65 void cpu_asr_write(CPUUniCore32State *env1, target_ulong val, target_ulong mask)
  66 {
  67     CPUUniCore32State *saved_env;
  68
  69     saved_env = env;
  70     env = env1;
  71     asr_write(val, mask);
  72     env = saved_env;
  73 }
  74
  75 void HELPER(asr_write)(target_ulong val, target_ulong mask)
  76 {
  77     asr_write(val, mask);
  78 }
  79
  80 /* Access to user mode registers from privileged modes.  */
  81 uint32_t HELPER(get_user_reg)(uint32_t regno)
  82 {
  83     uint32_t val;
  84
  85     if (regno == 29) {
  86         val = env->banked_r29[0];
  87     } else if (regno == 30) {
  88         val = env->banked_r30[0];
  89     } else {
  90         val = env->regs[regno];
  91     }
  92     return val;
  93 }
  94
  95 void HELPER(set_user_reg)(uint32_t regno, uint32_t val)
  96 {
  97     if (regno == 29) {
  98         env->banked_r29[0] = val;
  99     } else if (regno == 30) {
 100         env->banked_r30[0] = val;
 101     } else {
 102         env->regs[regno] = val;
 103     }
 104 }
 105
 106 /* ??? Flag setting arithmetic is awkward because we need to do comparisons.
 107    The only way to do that in TCG is a conditional branch, which clobbers
 108    all our temporaries.  For now implement these as helper functions.  */
 109
 110 uint32_t HELPER(add_cc)(uint32_t a, uint32_t b)
 111 {
 112     uint32_t result;
 113     result = a + b;
 114     env->NF = env->ZF = result;
 115     env->CF = result < a;
 116     env->VF = (a ^ b ^ -1) & (a ^ result);
 117     return result;
 118 }
 119
 120 uint32_t HELPER(adc_cc)(uint32_t a, uint32_t b)
 121 {
 122     uint32_t result;
 123     if (!env->CF) {
 124         result = a + b;
 125         env->CF = result < a;
 126     } else {
 127         result = a + b + 1;
 128         env->CF = result <= a;
 129     }
 130     env->VF = (a ^ b ^ -1) & (a ^ result);
 131     env->NF = env->ZF = result;
 132     return result;
 133 }
 134
 135 uint32_t HELPER(sub_cc)(uint32_t a, uint32_t b)
 136 {
 137     uint32_t result;
 138     result = a - b;
 139     env->NF = env->ZF = result;
 140     env->CF = a >= b;
 141     env->VF = (a ^ b) & (a ^ result);
 142     return result;
 143 }
 144
 145 uint32_t HELPER(sbc_cc)(uint32_t a, uint32_t b)
 146 {
 147     uint32_t result;
 148     if (!env->CF) {
 149         result = a - b - 1;
 150         env->CF = a > b;
 151     } else {
 152         result = a - b;
 153         env->CF = a >= b;
 154     }
 155     env->VF = (a ^ b) & (a ^ result);
 156     env->NF = env->ZF = result;
 157     return result;
 158 }
 159
 160 /* Similarly for variable shift instructions.  */
 161
 162 uint32_t HELPER(shl)(uint32_t x, uint32_t i)
 163 {
 164     int shift = i & 0xff;
 165     if (shift >= 32) {
 166         return 0;
 167     }
 168     return x << shift;
 169 }
 170
 171 uint32_t HELPER(shr)(uint32_t x, uint32_t i)
 172 {
 173     int shift = i & 0xff;
 174     if (shift >= 32) {
 175         return 0;
 176     }
 177     return (uint32_t)x >> shift;
 178 }
 179
 180 uint32_t HELPER(sar)(uint32_t x, uint32_t i)
 181 {
 182     int shift = i & 0xff;
 183     if (shift >= 32) {
 184         shift = 31;
 185     }
 186     return (int32_t)x >> shift;
 187 }
 188
 189 uint32_t HELPER(shl_cc)(uint32_t x, uint32_t i)
 190 {
 191     int shift = i & 0xff;
 192     if (shift >= 32) {
 193         if (shift == 32) {
 194             env->CF = x & 1;
 195         } else {
 196             env->CF = 0;
 197         }
 198         return 0;
 199     } else if (shift != 0) {
 200         env->CF = (x >> (32 - shift)) & 1;
 201         return x << shift;
 202     }
 203     return x;
 204 }
 205
 206 uint32_t HELPER(shr_cc)(uint32_t x, uint32_t i)
 207 {
 208     int shift = i & 0xff;
 209     if (shift >= 32) {
 210         if (shift == 32) {
 211             env->CF = (x >> 31) & 1;
 212         } else {
 213             env->CF = 0;
 214         }
 215         return 0;
 216     } else if (shift != 0) {
 217         env->CF = (x >> (shift - 1)) & 1;
 218         return x >> shift;
 219     }
 220     return x;
 221 }
 222
 223 uint32_t HELPER(sar_cc)(uint32_t x, uint32_t i)
 224 {
 225     int shift = i & 0xff;
 226     if (shift >= 32) {
 227         env->CF = (x >> 31) & 1;
 228         return (int32_t)x >> 31;
 229     } else if (shift != 0) {
 230         env->CF = (x >> (shift - 1)) & 1;
 231         return (int32_t)x >> shift;
 232     }
 233     return x;
 234 }
 235
 236 uint32_t HELPER(ror_cc)(uint32_t x, uint32_t i)
 237 {
 238     int shift1, shift;
 239     shift1 = i & 0xff;
 240     shift = shift1 & 0x1f;
 241     if (shift == 0) {
 242         if (shift1 != 0) {
 243             env->CF = (x >> 31) & 1;
 244         }
 245         return x;
 246     } else {
 247         env->CF = (x >> (shift - 1)) & 1;
 248         return ((uint32_t)x >> shift) | (x << (32 - shift));
 249     }
 250 }