target-arm/op_helper.c

   1 /*
   2  *  ARM helper routines
   3  *
   4  *  Copyright (c) 2005-2007 CodeSourcery, LLC
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #include "exec.h"
  20 #include "helper.h"
  21
  22 #define SIGNBIT (uint32_t)0x80000000
  23 #define SIGNBIT64 ((uint64_t)1 << 63)
  24
  25 void raise_exception(int tt)
  26 {
  27     env->exception_index = tt;
  28     cpu_loop_exit(env);
  29 }
  30
  31 uint32_t HELPER(neon_tbl)(uint32_t ireg, uint32_t def,
  32                           uint32_t rn, uint32_t maxindex)
  33 {
  34     uint32_t val;
  35     uint32_t tmp;
  36     int index;
  37     int shift;
  38     uint64_t *table;
  39     table = (uint64_t *)&env->vfp.regs[rn];
  40     val = 0;
  41     for (shift = 0; shift < 32; shift += 8) {
  42         index = (ireg >> shift) & 0xff;
  43         if (index < maxindex) {
  44             tmp = (table[index >> 3] >> ((index & 7) << 3)) & 0xff;
  45             val |= tmp << shift;
  46         } else {
  47             val |= def & (0xff << shift);
  48         }
  49     }
  50     return val;
  51 }
  52
  53 #if !defined(CONFIG_USER_ONLY)
  54
  55 #define MMUSUFFIX _mmu
  56
  57 #define SHIFT 0
  58 #include "softmmu_template.h"
  59
  60 #define SHIFT 1
  61 #include "softmmu_template.h"
  62
  63 #define SHIFT 2
  64 #include "softmmu_template.h"
  65
  66 #define SHIFT 3
  67 #include "softmmu_template.h"
  68
  69 /* try to fill the TLB and return an exception if error. If retaddr is
  70    NULL, it means that the function was called in C code (i.e. not
  71    from generated code or from helper.c) */
  72 /* XXX: fix it to restore all registers */
  73 void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr)
  74 {
  75     TranslationBlock *tb;
  76     CPUState *saved_env;
  77     unsigned long pc;
  78     int ret;
  79
  80     /* XXX: hack to restore env in all cases, even if not called from
  81        generated code */
  82     saved_env = env;
  83     env = cpu_single_env;
  84     ret = cpu_arm_handle_mmu_fault(env, addr, is_write, mmu_idx, 1);
  85     if (unlikely(ret)) {
  86         if (retaddr) {
  87             /* now we have a real cpu fault */
  88             pc = (unsigned long)retaddr;
  89             tb = tb_find_pc(pc);
  90             if (tb) {
  91                 /* the PC is inside the translated code. It means that we have
  92                    a virtual CPU fault */
  93                 cpu_restore_state(tb, env, pc);
  94             }
  95         }
  96         raise_exception(env->exception_index);
  97     }
  98     env = saved_env;
  99 }
 100 #endif
 101
 102 /* FIXME: Pass an axplicit pointer to QF to CPUState, and move saturating
 103    instructions into helper.c  */
 104 uint32_t HELPER(add_setq)(uint32_t a, uint32_t b)
 105 {
 106     uint32_t res = a + b;
 107     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT))
 108         env->QF = 1;
 109     return res;
 110 }
 111
 112 uint32_t HELPER(add_saturate)(uint32_t a, uint32_t b)
 113 {
 114     uint32_t res = a + b;
 115     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) {
 116         env->QF = 1;
 117         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 118     }
 119     return res;
 120 }
 121
 122 uint32_t HELPER(sub_saturate)(uint32_t a, uint32_t b)
 123 {
 124     uint32_t res = a - b;
 125     if (((res ^ a) & SIGNBIT) && ((a ^ b) & SIGNBIT)) {
 126         env->QF = 1;
 127         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 128     }
 129     return res;
 130 }
 131
 132 uint32_t HELPER(double_saturate)(int32_t val)
 133 {
 134     uint32_t res;
 135     if (val >= 0x40000000) {
 136         res = ~SIGNBIT;
 137         env->QF = 1;
 138     } else if (val <= (int32_t)0xc0000000) {
 139         res = SIGNBIT;
 140         env->QF = 1;
 141     } else {
 142         res = val << 1;
 143     }
 144     return res;
 145 }
 146
 147 uint32_t HELPER(add_usaturate)(uint32_t a, uint32_t b)
 148 {
 149     uint32_t res = a + b;
 150     if (res < a) {
 151         env->QF = 1;
 152         res = ~0;
 153     }
 154     return res;
 155 }
 156
 157 uint32_t HELPER(sub_usaturate)(uint32_t a, uint32_t b)
 158 {
 159     uint32_t res = a - b;
 160     if (res > a) {
 161         env->QF = 1;
 162         res = 0;
 163     }
 164     return res;
 165 }
 166
 167 /* Signed saturation.  */
 168 static inline uint32_t do_ssat(int32_t val, int shift)
 169 {
 170     int32_t top;
 171     uint32_t mask;
 172
 173     top = val >> shift;
 174     mask = (1u << shift) - 1;
 175     if (top > 0) {
 176         env->QF = 1;
 177         return mask;
 178     } else if (top < -1) {
 179         env->QF = 1;
 180         return ~mask;
 181     }
 182     return val;
 183 }
 184
 185 /* Unsigned saturation.  */
 186 static inline uint32_t do_usat(int32_t val, int shift)
 187 {
 188     uint32_t max;
 189
 190     max = (1u << shift) - 1;
 191     if (val < 0) {
 192         env->QF = 1;
 193         return 0;
 194     } else if (val > max) {
 195         env->QF = 1;
 196         return max;
 197     }
 198     return val;
 199 }
 200
 201 /* Signed saturate.  */
 202 uint32_t HELPER(ssat)(uint32_t x, uint32_t shift)
 203 {
 204     return do_ssat(x, shift);
 205 }
 206
 207 /* Dual halfword signed saturate.  */
 208 uint32_t HELPER(ssat16)(uint32_t x, uint32_t shift)
 209 {
 210     uint32_t res;
 211
 212     res = (uint16_t)do_ssat((int16_t)x, shift);
 213     res |= do_ssat(((int32_t)x) >> 16, shift) << 16;
 214     return res;
 215 }
 216
 217 /* Unsigned saturate.  */
 218 uint32_t HELPER(usat)(uint32_t x, uint32_t shift)
 219 {
 220     return do_usat(x, shift);
 221 }
 222
 223 /* Dual halfword unsigned saturate.  */
 224 uint32_t HELPER(usat16)(uint32_t x, uint32_t shift)
 225 {
 226     uint32_t res;
 227
 228     res = (uint16_t)do_usat((int16_t)x, shift);
 229     res |= do_usat(((int32_t)x) >> 16, shift) << 16;
 230     return res;
 231 }
 232
 233 void HELPER(wfi)(void)
 234 {
 235     env->exception_index = EXCP_HLT;
 236     env->halted = 1;
 237     cpu_loop_exit(env);
 238 }
 239
 240 void HELPER(exception)(uint32_t excp)
 241 {
 242     env->exception_index = excp;
 243     cpu_loop_exit(env);
 244 }
 245
 246 uint32_t HELPER(cpsr_read)(void)
 247 {
 248     return cpsr_read(env) & ~CPSR_EXEC;
 249 }
 250
 251 void HELPER(cpsr_write)(uint32_t val, uint32_t mask)
 252 {
 253     cpsr_write(env, val, mask);
 254 }
 255
 256 /* Access to user mode registers from privileged modes.  */
 257 uint32_t HELPER(get_user_reg)(uint32_t regno)
 258 {
 259     uint32_t val;
 260
 261     if (regno == 13) {
 262         val = env->banked_r13[0];
 263     } else if (regno == 14) {
 264         val = env->banked_r14[0];
 265     } else if (regno >= 8
 266                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 267         val = env->usr_regs[regno - 8];
 268     } else {
 269         val = env->regs[regno];
 270     }
 271     return val;
 272 }
 273
 274 void HELPER(set_user_reg)(uint32_t regno, uint32_t val)
 275 {
 276     if (regno == 13) {
 277         env->banked_r13[0] = val;
 278     } else if (regno == 14) {
 279         env->banked_r14[0] = val;
 280     } else if (regno >= 8
 281                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 282         env->usr_regs[regno - 8] = val;
 283     } else {
 284         env->regs[regno] = val;
 285     }
 286 }
 287
 288 /* ??? Flag setting arithmetic is awkward because we need to do comparisons.
 289    The only way to do that in TCG is a conditional branch, which clobbers
 290    all our temporaries.  For now implement these as helper functions.  */
 291
 292 uint32_t HELPER (add_cc)(uint32_t a, uint32_t b)
 293 {
 294     uint32_t result;
 295     result = a + b;
 296     env->NF = env->ZF = result;
 297     env->CF = result < a;
 298     env->VF = (a ^ b ^ -1) & (a ^ result);
 299     return result;
 300 }
 301
 302 uint32_t HELPER(adc_cc)(uint32_t a, uint32_t b)
 303 {
 304     uint32_t result;
 305     if (!env->CF) {
 306         result = a + b;
 307         env->CF = result < a;
 308     } else {
 309         result = a + b + 1;
 310         env->CF = result <= a;
 311     }
 312     env->VF = (a ^ b ^ -1) & (a ^ result);
 313     env->NF = env->ZF = result;
 314     return result;
 315 }
 316
 317 uint32_t HELPER(sub_cc)(uint32_t a, uint32_t b)
 318 {
 319     uint32_t result;
 320     result = a - b;
 321     env->NF = env->ZF = result;
 322     env->CF = a >= b;
 323     env->VF = (a ^ b) & (a ^ result);
 324     return result;
 325 }
 326
 327 uint32_t HELPER(sbc_cc)(uint32_t a, uint32_t b)
 328 {
 329     uint32_t result;
 330     if (!env->CF) {
 331         result = a - b - 1;
 332         env->CF = a > b;
 333     } else {
 334         result = a - b;
 335         env->CF = a >= b;
 336     }
 337     env->VF = (a ^ b) & (a ^ result);
 338     env->NF = env->ZF = result;
 339     return result;
 340 }
 341
 342 /* Similarly for variable shift instructions.  */
 343
 344 uint32_t HELPER(shl)(uint32_t x, uint32_t i)
 345 {
 346     int shift = i & 0xff;
 347     if (shift >= 32)
 348         return 0;
 349     return x << shift;
 350 }
 351
 352 uint32_t HELPER(shr)(uint32_t x, uint32_t i)
 353 {
 354     int shift = i & 0xff;
 355     if (shift >= 32)
 356         return 0;
 357     return (uint32_t)x >> shift;
 358 }
 359
 360 uint32_t HELPER(sar)(uint32_t x, uint32_t i)
 361 {
 362     int shift = i & 0xff;
 363     if (shift >= 32)
 364         shift = 31;
 365     return (int32_t)x >> shift;
 366 }
 367
 368 uint32_t HELPER(shl_cc)(uint32_t x, uint32_t i)
 369 {
 370     int shift = i & 0xff;
 371     if (shift >= 32) {
 372         if (shift == 32)
 373             env->CF = x & 1;
 374         else
 375             env->CF = 0;
 376         return 0;
 377     } else if (shift != 0) {
 378         env->CF = (x >> (32 - shift)) & 1;
 379         return x << shift;
 380     }
 381     return x;
 382 }
 383
 384 uint32_t HELPER(shr_cc)(uint32_t x, uint32_t i)
 385 {
 386     int shift = i & 0xff;
 387     if (shift >= 32) {
 388         if (shift == 32)
 389             env->CF = (x >> 31) & 1;
 390         else
 391             env->CF = 0;
 392         return 0;
 393     } else if (shift != 0) {
 394         env->CF = (x >> (shift - 1)) & 1;
 395         return x >> shift;
 396     }
 397     return x;
 398 }
 399
 400 uint32_t HELPER(sar_cc)(uint32_t x, uint32_t i)
 401 {
 402     int shift = i & 0xff;
 403     if (shift >= 32) {
 404         env->CF = (x >> 31) & 1;
 405         return (int32_t)x >> 31;
 406     } else if (shift != 0) {
 407         env->CF = (x >> (shift - 1)) & 1;
 408         return (int32_t)x >> shift;
 409     }
 410     return x;
 411 }
 412
 413 uint32_t HELPER(ror_cc)(uint32_t x, uint32_t i)
 414 {
 415     int shift1, shift;
 416     shift1 = i & 0xff;
 417     shift = shift1 & 0x1f;
 418     if (shift == 0) {
 419         if (shift1 != 0)
 420             env->CF = (x >> 31) & 1;
 421         return x;
 422     } else {
 423         env->CF = (x >> (shift - 1)) & 1;
 424         return ((uint32_t)x >> shift) | (x << (32 - shift));
 425     }
 426 }