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 "cpu.h"
  20 #include "dyngen-exec.h"
  21 #include "helper.h"
  22
  23 #define SIGNBIT (uint32_t)0x80000000
  24 #define SIGNBIT64 ((uint64_t)1 << 63)
  25
  26 #if !defined(CONFIG_USER_ONLY)
  27 static void raise_exception(int tt)
  28 {
  29     env->exception_index = tt;
  30     cpu_loop_exit(env);
  31 }
  32 #endif
  33
  34 uint32_t HELPER(neon_tbl)(uint32_t ireg, uint32_t def,
  35                           uint32_t rn, uint32_t maxindex)
  36 {
  37     uint32_t val;
  38     uint32_t tmp;
  39     int index;
  40     int shift;
  41     uint64_t *table;
  42     table = (uint64_t *)&env->vfp.regs[rn];
  43     val = 0;
  44     for (shift = 0; shift < 32; shift += 8) {
  45         index = (ireg >> shift) & 0xff;
  46         if (index < maxindex) {
  47             tmp = (table[index >> 3] >> ((index & 7) << 3)) & 0xff;
  48             val |= tmp << shift;
  49         } else {
  50             val |= def & (0xff << shift);
  51         }
  52     }
  53     return val;
  54 }
  55
  56 #if !defined(CONFIG_USER_ONLY)
  57
  58 #include "softmmu_exec.h"
  59
  60 #define MMUSUFFIX _mmu
  61
  62 #define SHIFT 0
  63 #include "softmmu_template.h"
  64
  65 #define SHIFT 1
  66 #include "softmmu_template.h"
  67
  68 #define SHIFT 2
  69 #include "softmmu_template.h"
  70
  71 #define SHIFT 3
  72 #include "softmmu_template.h"
  73
  74 /* try to fill the TLB and return an exception if error. If retaddr is
  75    NULL, it means that the function was called in C code (i.e. not
  76    from generated code or from helper.c) */
  77 /* XXX: fix it to restore all registers */
  78 void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr)
  79 {
  80     TranslationBlock *tb;
  81     CPUState *saved_env;
  82     unsigned long pc;
  83     int ret;
  84
  85     /* XXX: hack to restore env in all cases, even if not called from
  86        generated code */
  87     saved_env = env;
  88     env = cpu_single_env;
  89     ret = cpu_arm_handle_mmu_fault(env, addr, is_write, mmu_idx);
  90     if (unlikely(ret)) {
  91         if (retaddr) {
  92             /* now we have a real cpu fault */
  93             pc = (unsigned long)retaddr;
  94             tb = tb_find_pc(pc);
  95             if (tb) {
  96                 /* the PC is inside the translated code. It means that we have
  97                    a virtual CPU fault */
  98                 cpu_restore_state(tb, env, pc);
  99             }
 100         }
 101         raise_exception(env->exception_index);
 102     }
 103     env = saved_env;
 104 }
 105 #endif
 106
 107 /* FIXME: Pass an axplicit pointer to QF to CPUState, and move saturating
 108    instructions into helper.c  */
 109 uint32_t HELPER(add_setq)(uint32_t a, uint32_t b)
 110 {
 111     uint32_t res = a + b;
 112     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT))
 113         env->QF = 1;
 114     return res;
 115 }
 116
 117 uint32_t HELPER(add_saturate)(uint32_t a, uint32_t b)
 118 {
 119     uint32_t res = a + b;
 120     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) {
 121         env->QF = 1;
 122         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 123     }
 124     return res;
 125 }
 126
 127 uint32_t HELPER(sub_saturate)(uint32_t a, uint32_t b)
 128 {
 129     uint32_t res = a - b;
 130     if (((res ^ a) & SIGNBIT) && ((a ^ b) & SIGNBIT)) {
 131         env->QF = 1;
 132         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 133     }
 134     return res;
 135 }
 136
 137 uint32_t HELPER(double_saturate)(int32_t val)
 138 {
 139     uint32_t res;
 140     if (val >= 0x40000000) {
 141         res = ~SIGNBIT;
 142         env->QF = 1;
 143     } else if (val <= (int32_t)0xc0000000) {
 144         res = SIGNBIT;
 145         env->QF = 1;
 146     } else {
 147         res = val << 1;
 148     }
 149     return res;
 150 }
 151
 152 uint32_t HELPER(add_usaturate)(uint32_t a, uint32_t b)
 153 {
 154     uint32_t res = a + b;
 155     if (res < a) {
 156         env->QF = 1;
 157         res = ~0;
 158     }
 159     return res;
 160 }
 161
 162 uint32_t HELPER(sub_usaturate)(uint32_t a, uint32_t b)
 163 {
 164     uint32_t res = a - b;
 165     if (res > a) {
 166         env->QF = 1;
 167         res = 0;
 168     }
 169     return res;
 170 }
 171
 172 /* Signed saturation.  */
 173 static inline uint32_t do_ssat(int32_t val, int shift)
 174 {
 175     int32_t top;
 176     uint32_t mask;
 177
 178     top = val >> shift;
 179     mask = (1u << shift) - 1;
 180     if (top > 0) {
 181         env->QF = 1;
 182         return mask;
 183     } else if (top < -1) {
 184         env->QF = 1;
 185         return ~mask;
 186     }
 187     return val;
 188 }
 189
 190 /* Unsigned saturation.  */
 191 static inline uint32_t do_usat(int32_t val, int shift)
 192 {
 193     uint32_t max;
 194
 195     max = (1u << shift) - 1;
 196     if (val < 0) {
 197         env->QF = 1;
 198         return 0;
 199     } else if (val > max) {
 200         env->QF = 1;
 201         return max;
 202     }
 203     return val;
 204 }
 205
 206 /* Signed saturate.  */
 207 uint32_t HELPER(ssat)(uint32_t x, uint32_t shift)
 208 {
 209     return do_ssat(x, shift);
 210 }
 211
 212 /* Dual halfword signed saturate.  */
 213 uint32_t HELPER(ssat16)(uint32_t x, uint32_t shift)
 214 {
 215     uint32_t res;
 216
 217     res = (uint16_t)do_ssat((int16_t)x, shift);
 218     res |= do_ssat(((int32_t)x) >> 16, shift) << 16;
 219     return res;
 220 }
 221
 222 /* Unsigned saturate.  */
 223 uint32_t HELPER(usat)(uint32_t x, uint32_t shift)
 224 {
 225     return do_usat(x, shift);
 226 }
 227
 228 /* Dual halfword unsigned saturate.  */
 229 uint32_t HELPER(usat16)(uint32_t x, uint32_t shift)
 230 {
 231     uint32_t res;
 232
 233     res = (uint16_t)do_usat((int16_t)x, shift);
 234     res |= do_usat(((int32_t)x) >> 16, shift) << 16;
 235     return res;
 236 }
 237
 238 void HELPER(wfi)(void)
 239 {
 240     env->exception_index = EXCP_HLT;
 241     env->halted = 1;
 242     cpu_loop_exit(env);
 243 }
 244
 245 void HELPER(exception)(uint32_t excp)
 246 {
 247     env->exception_index = excp;
 248     cpu_loop_exit(env);
 249 }
 250
 251 uint32_t HELPER(cpsr_read)(void)
 252 {
 253     return cpsr_read(env) & ~CPSR_EXEC;
 254 }
 255
 256 void HELPER(cpsr_write)(uint32_t val, uint32_t mask)
 257 {
 258     cpsr_write(env, val, mask);
 259 }
 260
 261 /* Access to user mode registers from privileged modes.  */
 262 uint32_t HELPER(get_user_reg)(uint32_t regno)
 263 {
 264     uint32_t val;
 265
 266     if (regno == 13) {
 267         val = env->banked_r13[0];
 268     } else if (regno == 14) {
 269         val = env->banked_r14[0];
 270     } else if (regno >= 8
 271                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 272         val = env->usr_regs[regno - 8];
 273     } else {
 274         val = env->regs[regno];
 275     }
 276     return val;
 277 }
 278
 279 void HELPER(set_user_reg)(uint32_t regno, uint32_t val)
 280 {
 281     if (regno == 13) {
 282         env->banked_r13[0] = val;
 283     } else if (regno == 14) {
 284         env->banked_r14[0] = val;
 285     } else if (regno >= 8
 286                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 287         env->usr_regs[regno - 8] = val;
 288     } else {
 289         env->regs[regno] = val;
 290     }
 291 }
 292
 293 /* ??? Flag setting arithmetic is awkward because we need to do comparisons.
 294    The only way to do that in TCG is a conditional branch, which clobbers
 295    all our temporaries.  For now implement these as helper functions.  */
 296
 297 uint32_t HELPER (add_cc)(uint32_t a, uint32_t b)
 298 {
 299     uint32_t result;
 300     result = a + b;
 301     env->NF = env->ZF = result;
 302     env->CF = result < a;
 303     env->VF = (a ^ b ^ -1) & (a ^ result);
 304     return result;
 305 }
 306
 307 uint32_t HELPER(adc_cc)(uint32_t a, uint32_t b)
 308 {
 309     uint32_t result;
 310     if (!env->CF) {
 311         result = a + b;
 312         env->CF = result < a;
 313     } else {
 314         result = a + b + 1;
 315         env->CF = result <= a;
 316     }
 317     env->VF = (a ^ b ^ -1) & (a ^ result);
 318     env->NF = env->ZF = result;
 319     return result;
 320 }
 321
 322 uint32_t HELPER(sub_cc)(uint32_t a, uint32_t b)
 323 {
 324     uint32_t result;
 325     result = a - b;
 326     env->NF = env->ZF = result;
 327     env->CF = a >= b;
 328     env->VF = (a ^ b) & (a ^ result);
 329     return result;
 330 }
 331
 332 uint32_t HELPER(sbc_cc)(uint32_t a, uint32_t b)
 333 {
 334     uint32_t result;
 335     if (!env->CF) {
 336         result = a - b - 1;
 337         env->CF = a > b;
 338     } else {
 339         result = a - b;
 340         env->CF = a >= b;
 341     }
 342     env->VF = (a ^ b) & (a ^ result);
 343     env->NF = env->ZF = result;
 344     return result;
 345 }
 346
 347 /* Similarly for variable shift instructions.  */
 348
 349 uint32_t HELPER(shl)(uint32_t x, uint32_t i)
 350 {
 351     int shift = i & 0xff;
 352     if (shift >= 32)
 353         return 0;
 354     return x << shift;
 355 }
 356
 357 uint32_t HELPER(shr)(uint32_t x, uint32_t i)
 358 {
 359     int shift = i & 0xff;
 360     if (shift >= 32)
 361         return 0;
 362     return (uint32_t)x >> shift;
 363 }
 364
 365 uint32_t HELPER(sar)(uint32_t x, uint32_t i)
 366 {
 367     int shift = i & 0xff;
 368     if (shift >= 32)
 369         shift = 31;
 370     return (int32_t)x >> shift;
 371 }
 372
 373 uint32_t HELPER(shl_cc)(uint32_t x, uint32_t i)
 374 {
 375     int shift = i & 0xff;
 376     if (shift >= 32) {
 377         if (shift == 32)
 378             env->CF = x & 1;
 379         else
 380             env->CF = 0;
 381         return 0;
 382     } else if (shift != 0) {
 383         env->CF = (x >> (32 - shift)) & 1;
 384         return x << shift;
 385     }
 386     return x;
 387 }
 388
 389 uint32_t HELPER(shr_cc)(uint32_t x, uint32_t i)
 390 {
 391     int shift = i & 0xff;
 392     if (shift >= 32) {
 393         if (shift == 32)
 394             env->CF = (x >> 31) & 1;
 395         else
 396             env->CF = 0;
 397         return 0;
 398     } else if (shift != 0) {
 399         env->CF = (x >> (shift - 1)) & 1;
 400         return x >> shift;
 401     }
 402     return x;
 403 }
 404
 405 uint32_t HELPER(sar_cc)(uint32_t x, uint32_t i)
 406 {
 407     int shift = i & 0xff;
 408     if (shift >= 32) {
 409         env->CF = (x >> 31) & 1;
 410         return (int32_t)x >> 31;
 411     } else if (shift != 0) {
 412         env->CF = (x >> (shift - 1)) & 1;
 413         return (int32_t)x >> shift;
 414     }
 415     return x;
 416 }
 417
 418 uint32_t HELPER(ror_cc)(uint32_t x, uint32_t i)
 419 {
 420     int shift1, shift;
 421     shift1 = i & 0xff;
 422     shift = shift1 & 0x1f;
 423     if (shift == 0) {
 424         if (shift1 != 0)
 425             env->CF = (x >> 31) & 1;
 426         return x;
 427     } else {
 428         env->CF = (x >> (shift - 1)) & 1;
 429         return ((uint32_t)x >> shift) | (x << (32 - shift));
 430     }
 431 }