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(CPUState *env1, target_ulong addr, int is_write, int mmu_idx,
  79               void *retaddr)
  80 {
  81     TranslationBlock *tb;
  82     CPUState *saved_env;
  83     unsigned long pc;
  84     int ret;
  85
  86     saved_env = env;
  87     ret = cpu_arm_handle_mmu_fault(env, addr, is_write, mmu_idx);
  88     if (unlikely(ret)) {
  89         if (retaddr) {
  90             /* now we have a real cpu fault */
  91             pc = (unsigned long)retaddr;
  92             tb = tb_find_pc(pc);
  93             if (tb) {
  94                 /* the PC is inside the translated code. It means that we have
  95                    a virtual CPU fault */
  96                 cpu_restore_state(tb, env, pc);
  97             }
  98         }
  99         raise_exception(env->exception_index);
 100     }
 101     env = saved_env;
 102 }
 103 #endif
 104
 105 /* FIXME: Pass an axplicit pointer to QF to CPUState, and move saturating
 106    instructions into helper.c  */
 107 uint32_t HELPER(add_setq)(uint32_t a, uint32_t b)
 108 {
 109     uint32_t res = a + b;
 110     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT))
 111         env->QF = 1;
 112     return res;
 113 }
 114
 115 uint32_t HELPER(add_saturate)(uint32_t a, uint32_t b)
 116 {
 117     uint32_t res = a + b;
 118     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) {
 119         env->QF = 1;
 120         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 121     }
 122     return res;
 123 }
 124
 125 uint32_t HELPER(sub_saturate)(uint32_t a, uint32_t b)
 126 {
 127     uint32_t res = a - b;
 128     if (((res ^ a) & SIGNBIT) && ((a ^ b) & SIGNBIT)) {
 129         env->QF = 1;
 130         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 131     }
 132     return res;
 133 }
 134
 135 uint32_t HELPER(double_saturate)(int32_t val)
 136 {
 137     uint32_t res;
 138     if (val >= 0x40000000) {
 139         res = ~SIGNBIT;
 140         env->QF = 1;
 141     } else if (val <= (int32_t)0xc0000000) {
 142         res = SIGNBIT;
 143         env->QF = 1;
 144     } else {
 145         res = val << 1;
 146     }
 147     return res;
 148 }
 149
 150 uint32_t HELPER(add_usaturate)(uint32_t a, uint32_t b)
 151 {
 152     uint32_t res = a + b;
 153     if (res < a) {
 154         env->QF = 1;
 155         res = ~0;
 156     }
 157     return res;
 158 }
 159
 160 uint32_t HELPER(sub_usaturate)(uint32_t a, uint32_t b)
 161 {
 162     uint32_t res = a - b;
 163     if (res > a) {
 164         env->QF = 1;
 165         res = 0;
 166     }
 167     return res;
 168 }
 169
 170 /* Signed saturation.  */
 171 static inline uint32_t do_ssat(int32_t val, int shift)
 172 {
 173     int32_t top;
 174     uint32_t mask;
 175
 176     top = val >> shift;
 177     mask = (1u << shift) - 1;
 178     if (top > 0) {
 179         env->QF = 1;
 180         return mask;
 181     } else if (top < -1) {
 182         env->QF = 1;
 183         return ~mask;
 184     }
 185     return val;
 186 }
 187
 188 /* Unsigned saturation.  */
 189 static inline uint32_t do_usat(int32_t val, int shift)
 190 {
 191     uint32_t max;
 192
 193     max = (1u << shift) - 1;
 194     if (val < 0) {
 195         env->QF = 1;
 196         return 0;
 197     } else if (val > max) {
 198         env->QF = 1;
 199         return max;
 200     }
 201     return val;
 202 }
 203
 204 /* Signed saturate.  */
 205 uint32_t HELPER(ssat)(uint32_t x, uint32_t shift)
 206 {
 207     return do_ssat(x, shift);
 208 }
 209
 210 /* Dual halfword signed saturate.  */
 211 uint32_t HELPER(ssat16)(uint32_t x, uint32_t shift)
 212 {
 213     uint32_t res;
 214
 215     res = (uint16_t)do_ssat((int16_t)x, shift);
 216     res |= do_ssat(((int32_t)x) >> 16, shift) << 16;
 217     return res;
 218 }
 219
 220 /* Unsigned saturate.  */
 221 uint32_t HELPER(usat)(uint32_t x, uint32_t shift)
 222 {
 223     return do_usat(x, shift);
 224 }
 225
 226 /* Dual halfword unsigned saturate.  */
 227 uint32_t HELPER(usat16)(uint32_t x, uint32_t shift)
 228 {
 229     uint32_t res;
 230
 231     res = (uint16_t)do_usat((int16_t)x, shift);
 232     res |= do_usat(((int32_t)x) >> 16, shift) << 16;
 233     return res;
 234 }
 235
 236 void HELPER(wfi)(void)
 237 {
 238     env->exception_index = EXCP_HLT;
 239     env->halted = 1;
 240     cpu_loop_exit(env);
 241 }
 242
 243 void HELPER(exception)(uint32_t excp)
 244 {
 245     env->exception_index = excp;
 246     cpu_loop_exit(env);
 247 }
 248
 249 uint32_t HELPER(cpsr_read)(void)
 250 {
 251     return cpsr_read(env) & ~CPSR_EXEC;
 252 }
 253
 254 void HELPER(cpsr_write)(uint32_t val, uint32_t mask)
 255 {
 256     cpsr_write(env, val, mask);
 257 }
 258
 259 /* Access to user mode registers from privileged modes.  */
 260 uint32_t HELPER(get_user_reg)(uint32_t regno)
 261 {
 262     uint32_t val;
 263
 264     if (regno == 13) {
 265         val = env->banked_r13[0];
 266     } else if (regno == 14) {
 267         val = env->banked_r14[0];
 268     } else if (regno >= 8
 269                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 270         val = env->usr_regs[regno - 8];
 271     } else {
 272         val = env->regs[regno];
 273     }
 274     return val;
 275 }
 276
 277 void HELPER(set_user_reg)(uint32_t regno, uint32_t val)
 278 {
 279     if (regno == 13) {
 280         env->banked_r13[0] = val;
 281     } else if (regno == 14) {
 282         env->banked_r14[0] = val;
 283     } else if (regno >= 8
 284                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 285         env->usr_regs[regno - 8] = val;
 286     } else {
 287         env->regs[regno] = val;
 288     }
 289 }
 290
 291 /* ??? Flag setting arithmetic is awkward because we need to do comparisons.
 292    The only way to do that in TCG is a conditional branch, which clobbers
 293    all our temporaries.  For now implement these as helper functions.  */
 294
 295 uint32_t HELPER (add_cc)(uint32_t a, uint32_t b)
 296 {
 297     uint32_t result;
 298     result = a + b;
 299     env->NF = env->ZF = result;
 300     env->CF = result < a;
 301     env->VF = (a ^ b ^ -1) & (a ^ result);
 302     return result;
 303 }
 304
 305 uint32_t HELPER(adc_cc)(uint32_t a, uint32_t b)
 306 {
 307     uint32_t result;
 308     if (!env->CF) {
 309         result = a + b;
 310         env->CF = result < a;
 311     } else {
 312         result = a + b + 1;
 313         env->CF = result <= a;
 314     }
 315     env->VF = (a ^ b ^ -1) & (a ^ result);
 316     env->NF = env->ZF = result;
 317     return result;
 318 }
 319
 320 uint32_t HELPER(sub_cc)(uint32_t a, uint32_t b)
 321 {
 322     uint32_t result;
 323     result = a - b;
 324     env->NF = env->ZF = result;
 325     env->CF = a >= b;
 326     env->VF = (a ^ b) & (a ^ result);
 327     return result;
 328 }
 329
 330 uint32_t HELPER(sbc_cc)(uint32_t a, uint32_t b)
 331 {
 332     uint32_t result;
 333     if (!env->CF) {
 334         result = a - b - 1;
 335         env->CF = a > b;
 336     } else {
 337         result = a - b;
 338         env->CF = a >= b;
 339     }
 340     env->VF = (a ^ b) & (a ^ result);
 341     env->NF = env->ZF = result;
 342     return result;
 343 }
 344
 345 /* Similarly for variable shift instructions.  */
 346
 347 uint32_t HELPER(shl)(uint32_t x, uint32_t i)
 348 {
 349     int shift = i & 0xff;
 350     if (shift >= 32)
 351         return 0;
 352     return x << shift;
 353 }
 354
 355 uint32_t HELPER(shr)(uint32_t x, uint32_t i)
 356 {
 357     int shift = i & 0xff;
 358     if (shift >= 32)
 359         return 0;
 360     return (uint32_t)x >> shift;
 361 }
 362
 363 uint32_t HELPER(sar)(uint32_t x, uint32_t i)
 364 {
 365     int shift = i & 0xff;
 366     if (shift >= 32)
 367         shift = 31;
 368     return (int32_t)x >> shift;
 369 }
 370
 371 uint32_t HELPER(shl_cc)(uint32_t x, uint32_t i)
 372 {
 373     int shift = i & 0xff;
 374     if (shift >= 32) {
 375         if (shift == 32)
 376             env->CF = x & 1;
 377         else
 378             env->CF = 0;
 379         return 0;
 380     } else if (shift != 0) {
 381         env->CF = (x >> (32 - shift)) & 1;
 382         return x << shift;
 383     }
 384     return x;
 385 }
 386
 387 uint32_t HELPER(shr_cc)(uint32_t x, uint32_t i)
 388 {
 389     int shift = i & 0xff;
 390     if (shift >= 32) {
 391         if (shift == 32)
 392             env->CF = (x >> 31) & 1;
 393         else
 394             env->CF = 0;
 395         return 0;
 396     } else if (shift != 0) {
 397         env->CF = (x >> (shift - 1)) & 1;
 398         return x >> shift;
 399     }
 400     return x;
 401 }
 402
 403 uint32_t HELPER(sar_cc)(uint32_t x, uint32_t i)
 404 {
 405     int shift = i & 0xff;
 406     if (shift >= 32) {
 407         env->CF = (x >> 31) & 1;
 408         return (int32_t)x >> 31;
 409     } else if (shift != 0) {
 410         env->CF = (x >> (shift - 1)) & 1;
 411         return (int32_t)x >> shift;
 412     }
 413     return x;
 414 }
 415
 416 uint32_t HELPER(ror_cc)(uint32_t x, uint32_t i)
 417 {
 418     int shift1, shift;
 419     shift1 = i & 0xff;
 420     shift = shift1 & 0x1f;
 421     if (shift == 0) {
 422         if (shift1 != 0)
 423             env->CF = (x >> 31) & 1;
 424         return x;
 425     } else {
 426         env->CF = (x >> (shift - 1)) & 1;
 427         return ((uint32_t)x >> shift) | (x << (32 - shift));
 428     }
 429 }