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     env = env1;
  88     ret = cpu_arm_handle_mmu_fault(env, addr, is_write, mmu_idx);
  89     if (unlikely(ret)) {
  90         if (retaddr) {
  91             /* now we have a real cpu fault */
  92             pc = (unsigned long)retaddr;
  93             tb = tb_find_pc(pc);
  94             if (tb) {
  95                 /* the PC is inside the translated code. It means that we have
  96                    a virtual CPU fault */
  97                 cpu_restore_state(tb, env, pc);
  98             }
  99         }
 100         raise_exception(env->exception_index);
 101     }
 102     env = saved_env;
 103 }
 104 #endif
 105
 106 /* FIXME: Pass an axplicit pointer to QF to CPUState, and move saturating
 107    instructions into helper.c  */
 108 uint32_t HELPER(add_setq)(uint32_t a, uint32_t b)
 109 {
 110     uint32_t res = a + b;
 111     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT))
 112         env->QF = 1;
 113     return res;
 114 }
 115
 116 uint32_t HELPER(add_saturate)(uint32_t a, uint32_t b)
 117 {
 118     uint32_t res = a + b;
 119     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) {
 120         env->QF = 1;
 121         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 122     }
 123     return res;
 124 }
 125
 126 uint32_t HELPER(sub_saturate)(uint32_t a, uint32_t b)
 127 {
 128     uint32_t res = a - b;
 129     if (((res ^ a) & SIGNBIT) && ((a ^ b) & SIGNBIT)) {
 130         env->QF = 1;
 131         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 132     }
 133     return res;
 134 }
 135
 136 uint32_t HELPER(double_saturate)(int32_t val)
 137 {
 138     uint32_t res;
 139     if (val >= 0x40000000) {
 140         res = ~SIGNBIT;
 141         env->QF = 1;
 142     } else if (val <= (int32_t)0xc0000000) {
 143         res = SIGNBIT;
 144         env->QF = 1;
 145     } else {
 146         res = val << 1;
 147     }
 148     return res;
 149 }
 150
 151 uint32_t HELPER(add_usaturate)(uint32_t a, uint32_t b)
 152 {
 153     uint32_t res = a + b;
 154     if (res < a) {
 155         env->QF = 1;
 156         res = ~0;
 157     }
 158     return res;
 159 }
 160
 161 uint32_t HELPER(sub_usaturate)(uint32_t a, uint32_t b)
 162 {
 163     uint32_t res = a - b;
 164     if (res > a) {
 165         env->QF = 1;
 166         res = 0;
 167     }
 168     return res;
 169 }
 170
 171 /* Signed saturation.  */
 172 static inline uint32_t do_ssat(int32_t val, int shift)
 173 {
 174     int32_t top;
 175     uint32_t mask;
 176
 177     top = val >> shift;
 178     mask = (1u << shift) - 1;
 179     if (top > 0) {
 180         env->QF = 1;
 181         return mask;
 182     } else if (top < -1) {
 183         env->QF = 1;
 184         return ~mask;
 185     }
 186     return val;
 187 }
 188
 189 /* Unsigned saturation.  */
 190 static inline uint32_t do_usat(int32_t val, int shift)
 191 {
 192     uint32_t max;
 193
 194     max = (1u << shift) - 1;
 195     if (val < 0) {
 196         env->QF = 1;
 197         return 0;
 198     } else if (val > max) {
 199         env->QF = 1;
 200         return max;
 201     }
 202     return val;
 203 }
 204
 205 /* Signed saturate.  */
 206 uint32_t HELPER(ssat)(uint32_t x, uint32_t shift)
 207 {
 208     return do_ssat(x, shift);
 209 }
 210
 211 /* Dual halfword signed saturate.  */
 212 uint32_t HELPER(ssat16)(uint32_t x, uint32_t shift)
 213 {
 214     uint32_t res;
 215
 216     res = (uint16_t)do_ssat((int16_t)x, shift);
 217     res |= do_ssat(((int32_t)x) >> 16, shift) << 16;
 218     return res;
 219 }
 220
 221 /* Unsigned saturate.  */
 222 uint32_t HELPER(usat)(uint32_t x, uint32_t shift)
 223 {
 224     return do_usat(x, shift);
 225 }
 226
 227 /* Dual halfword unsigned saturate.  */
 228 uint32_t HELPER(usat16)(uint32_t x, uint32_t shift)
 229 {
 230     uint32_t res;
 231
 232     res = (uint16_t)do_usat((int16_t)x, shift);
 233     res |= do_usat(((int32_t)x) >> 16, shift) << 16;
 234     return res;
 235 }
 236
 237 void HELPER(wfi)(void)
 238 {
 239     env->exception_index = EXCP_HLT;
 240     env->halted = 1;
 241     cpu_loop_exit(env);
 242 }
 243
 244 void HELPER(exception)(uint32_t excp)
 245 {
 246     env->exception_index = excp;
 247     cpu_loop_exit(env);
 248 }
 249
 250 uint32_t HELPER(cpsr_read)(void)
 251 {
 252     return cpsr_read(env) & ~CPSR_EXEC;
 253 }
 254
 255 void HELPER(cpsr_write)(uint32_t val, uint32_t mask)
 256 {
 257     cpsr_write(env, val, mask);
 258 }
 259
 260 /* Access to user mode registers from privileged modes.  */
 261 uint32_t HELPER(get_user_reg)(uint32_t regno)
 262 {
 263     uint32_t val;
 264
 265     if (regno == 13) {
 266         val = env->banked_r13[0];
 267     } else if (regno == 14) {
 268         val = env->banked_r14[0];
 269     } else if (regno >= 8
 270                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 271         val = env->usr_regs[regno - 8];
 272     } else {
 273         val = env->regs[regno];
 274     }
 275     return val;
 276 }
 277
 278 void HELPER(set_user_reg)(uint32_t regno, uint32_t val)
 279 {
 280     if (regno == 13) {
 281         env->banked_r13[0] = val;
 282     } else if (regno == 14) {
 283         env->banked_r14[0] = val;
 284     } else if (regno >= 8
 285                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 286         env->usr_regs[regno - 8] = val;
 287     } else {
 288         env->regs[regno] = val;
 289     }
 290 }
 291
 292 /* ??? Flag setting arithmetic is awkward because we need to do comparisons.
 293    The only way to do that in TCG is a conditional branch, which clobbers
 294    all our temporaries.  For now implement these as helper functions.  */
 295
 296 uint32_t HELPER (add_cc)(uint32_t a, uint32_t b)
 297 {
 298     uint32_t result;
 299     result = a + b;
 300     env->NF = env->ZF = result;
 301     env->CF = result < a;
 302     env->VF = (a ^ b ^ -1) & (a ^ result);
 303     return result;
 304 }
 305
 306 uint32_t HELPER(adc_cc)(uint32_t a, uint32_t b)
 307 {
 308     uint32_t result;
 309     if (!env->CF) {
 310         result = a + b;
 311         env->CF = result < a;
 312     } else {
 313         result = a + b + 1;
 314         env->CF = result <= a;
 315     }
 316     env->VF = (a ^ b ^ -1) & (a ^ result);
 317     env->NF = env->ZF = result;
 318     return result;
 319 }
 320
 321 uint32_t HELPER(sub_cc)(uint32_t a, uint32_t b)
 322 {
 323     uint32_t result;
 324     result = a - b;
 325     env->NF = env->ZF = result;
 326     env->CF = a >= b;
 327     env->VF = (a ^ b) & (a ^ result);
 328     return result;
 329 }
 330
 331 uint32_t HELPER(sbc_cc)(uint32_t a, uint32_t b)
 332 {
 333     uint32_t result;
 334     if (!env->CF) {
 335         result = a - b - 1;
 336         env->CF = a > b;
 337     } else {
 338         result = a - b;
 339         env->CF = a >= b;
 340     }
 341     env->VF = (a ^ b) & (a ^ result);
 342     env->NF = env->ZF = result;
 343     return result;
 344 }
 345
 346 /* Similarly for variable shift instructions.  */
 347
 348 uint32_t HELPER(shl)(uint32_t x, uint32_t i)
 349 {
 350     int shift = i & 0xff;
 351     if (shift >= 32)
 352         return 0;
 353     return x << shift;
 354 }
 355
 356 uint32_t HELPER(shr)(uint32_t x, uint32_t i)
 357 {
 358     int shift = i & 0xff;
 359     if (shift >= 32)
 360         return 0;
 361     return (uint32_t)x >> shift;
 362 }
 363
 364 uint32_t HELPER(sar)(uint32_t x, uint32_t i)
 365 {
 366     int shift = i & 0xff;
 367     if (shift >= 32)
 368         shift = 31;
 369     return (int32_t)x >> shift;
 370 }
 371
 372 uint32_t HELPER(shl_cc)(uint32_t x, uint32_t i)
 373 {
 374     int shift = i & 0xff;
 375     if (shift >= 32) {
 376         if (shift == 32)
 377             env->CF = x & 1;
 378         else
 379             env->CF = 0;
 380         return 0;
 381     } else if (shift != 0) {
 382         env->CF = (x >> (32 - shift)) & 1;
 383         return x << shift;
 384     }
 385     return x;
 386 }
 387
 388 uint32_t HELPER(shr_cc)(uint32_t x, uint32_t i)
 389 {
 390     int shift = i & 0xff;
 391     if (shift >= 32) {
 392         if (shift == 32)
 393             env->CF = (x >> 31) & 1;
 394         else
 395             env->CF = 0;
 396         return 0;
 397     } else if (shift != 0) {
 398         env->CF = (x >> (shift - 1)) & 1;
 399         return x >> shift;
 400     }
 401     return x;
 402 }
 403
 404 uint32_t HELPER(sar_cc)(uint32_t x, uint32_t i)
 405 {
 406     int shift = i & 0xff;
 407     if (shift >= 32) {
 408         env->CF = (x >> 31) & 1;
 409         return (int32_t)x >> 31;
 410     } else if (shift != 0) {
 411         env->CF = (x >> (shift - 1)) & 1;
 412         return (int32_t)x >> shift;
 413     }
 414     return x;
 415 }
 416
 417 uint32_t HELPER(ror_cc)(uint32_t x, uint32_t i)
 418 {
 419     int shift1, shift;
 420     shift1 = i & 0xff;
 421     shift = shift1 & 0x1f;
 422     if (shift == 0) {
 423         if (shift1 != 0)
 424             env->CF = (x >> 31) & 1;
 425         return x;
 426     } else {
 427         env->CF = (x >> (shift - 1)) & 1;
 428         return ((uint32_t)x >> shift) | (x << (32 - shift));
 429     }
 430 }