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 "helper.h"
  21
  22 #define SIGNBIT (uint32_t)0x80000000
  23 #define SIGNBIT64 ((uint64_t)1 << 63)
  24
  25 static void raise_exception(CPUARMState *env, int tt)
  26 {
  27     env->exception_index = tt;
  28     cpu_loop_exit(env);
  29 }
  30
  31 uint32_t HELPER(neon_tbl)(CPUARMState *env, 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 #include "exec/softmmu_exec.h"
  56
  57 #define MMUSUFFIX _mmu
  58
  59 #define SHIFT 0
  60 #include "exec/softmmu_template.h"
  61
  62 #define SHIFT 1
  63 #include "exec/softmmu_template.h"
  64
  65 #define SHIFT 2
  66 #include "exec/softmmu_template.h"
  67
  68 #define SHIFT 3
  69 #include "exec/softmmu_template.h"
  70
  71 /* try to fill the TLB and return an exception if error. If retaddr is
  72    NULL, it means that the function was called in C code (i.e. not
  73    from generated code or from helper.c) */
  74 void tlb_fill(CPUARMState *env, target_ulong addr, int is_write, int mmu_idx,
  75               uintptr_t retaddr)
  76 {
  77     int ret;
  78
  79     ret = cpu_arm_handle_mmu_fault(env, addr, is_write, mmu_idx);
  80     if (unlikely(ret)) {
  81         if (retaddr) {
  82             /* now we have a real cpu fault */
  83             cpu_restore_state(env, retaddr);
  84         }
  85         raise_exception(env, env->exception_index);
  86     }
  87 }
  88 #endif
  89
  90 uint32_t HELPER(add_setq)(CPUARMState *env, uint32_t a, uint32_t b)
  91 {
  92     uint32_t res = a + b;
  93     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT))
  94         env->QF = 1;
  95     return res;
  96 }
  97
  98 uint32_t HELPER(add_saturate)(CPUARMState *env, uint32_t a, uint32_t b)
  99 {
 100     uint32_t res = a + b;
 101     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) {
 102         env->QF = 1;
 103         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 104     }
 105     return res;
 106 }
 107
 108 uint32_t HELPER(sub_saturate)(CPUARMState *env, 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         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 114     }
 115     return res;
 116 }
 117
 118 uint32_t HELPER(double_saturate)(CPUARMState *env, int32_t val)
 119 {
 120     uint32_t res;
 121     if (val >= 0x40000000) {
 122         res = ~SIGNBIT;
 123         env->QF = 1;
 124     } else if (val <= (int32_t)0xc0000000) {
 125         res = SIGNBIT;
 126         env->QF = 1;
 127     } else {
 128         res = val << 1;
 129     }
 130     return res;
 131 }
 132
 133 uint32_t HELPER(add_usaturate)(CPUARMState *env, uint32_t a, uint32_t b)
 134 {
 135     uint32_t res = a + b;
 136     if (res < a) {
 137         env->QF = 1;
 138         res = ~0;
 139     }
 140     return res;
 141 }
 142
 143 uint32_t HELPER(sub_usaturate)(CPUARMState *env, uint32_t a, uint32_t b)
 144 {
 145     uint32_t res = a - b;
 146     if (res > a) {
 147         env->QF = 1;
 148         res = 0;
 149     }
 150     return res;
 151 }
 152
 153 /* Signed saturation.  */
 154 static inline uint32_t do_ssat(CPUARMState *env, int32_t val, int shift)
 155 {
 156     int32_t top;
 157     uint32_t mask;
 158
 159     top = val >> shift;
 160     mask = (1u << shift) - 1;
 161     if (top > 0) {
 162         env->QF = 1;
 163         return mask;
 164     } else if (top < -1) {
 165         env->QF = 1;
 166         return ~mask;
 167     }
 168     return val;
 169 }
 170
 171 /* Unsigned saturation.  */
 172 static inline uint32_t do_usat(CPUARMState *env, int32_t val, int shift)
 173 {
 174     uint32_t max;
 175
 176     max = (1u << shift) - 1;
 177     if (val < 0) {
 178         env->QF = 1;
 179         return 0;
 180     } else if (val > max) {
 181         env->QF = 1;
 182         return max;
 183     }
 184     return val;
 185 }
 186
 187 /* Signed saturate.  */
 188 uint32_t HELPER(ssat)(CPUARMState *env, uint32_t x, uint32_t shift)
 189 {
 190     return do_ssat(env, x, shift);
 191 }
 192
 193 /* Dual halfword signed saturate.  */
 194 uint32_t HELPER(ssat16)(CPUARMState *env, uint32_t x, uint32_t shift)
 195 {
 196     uint32_t res;
 197
 198     res = (uint16_t)do_ssat(env, (int16_t)x, shift);
 199     res |= do_ssat(env, ((int32_t)x) >> 16, shift) << 16;
 200     return res;
 201 }
 202
 203 /* Unsigned saturate.  */
 204 uint32_t HELPER(usat)(CPUARMState *env, uint32_t x, uint32_t shift)
 205 {
 206     return do_usat(env, x, shift);
 207 }
 208
 209 /* Dual halfword unsigned saturate.  */
 210 uint32_t HELPER(usat16)(CPUARMState *env, uint32_t x, uint32_t shift)
 211 {
 212     uint32_t res;
 213
 214     res = (uint16_t)do_usat(env, (int16_t)x, shift);
 215     res |= do_usat(env, ((int32_t)x) >> 16, shift) << 16;
 216     return res;
 217 }
 218
 219 void HELPER(wfi)(CPUARMState *env)
 220 {
 221     env->exception_index = EXCP_HLT;
 222     env->halted = 1;
 223     cpu_loop_exit(env);
 224 }
 225
 226 void HELPER(exception)(CPUARMState *env, uint32_t excp)
 227 {
 228     env->exception_index = excp;
 229     cpu_loop_exit(env);
 230 }
 231
 232 uint32_t HELPER(cpsr_read)(CPUARMState *env)
 233 {
 234     return cpsr_read(env) & ~CPSR_EXEC;
 235 }
 236
 237 void HELPER(cpsr_write)(CPUARMState *env, uint32_t val, uint32_t mask)
 238 {
 239     cpsr_write(env, val, mask);
 240 }
 241
 242 /* Access to user mode registers from privileged modes.  */
 243 uint32_t HELPER(get_user_reg)(CPUARMState *env, uint32_t regno)
 244 {
 245     uint32_t val;
 246
 247     if (regno == 13) {
 248         val = env->banked_r13[0];
 249     } else if (regno == 14) {
 250         val = env->banked_r14[0];
 251     } else if (regno >= 8
 252                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 253         val = env->usr_regs[regno - 8];
 254     } else {
 255         val = env->regs[regno];
 256     }
 257     return val;
 258 }
 259
 260 void HELPER(set_user_reg)(CPUARMState *env, uint32_t regno, uint32_t val)
 261 {
 262     if (regno == 13) {
 263         env->banked_r13[0] = val;
 264     } else if (regno == 14) {
 265         env->banked_r14[0] = val;
 266     } else if (regno >= 8
 267                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 268         env->usr_regs[regno - 8] = val;
 269     } else {
 270         env->regs[regno] = val;
 271     }
 272 }
 273
 274 void HELPER(set_cp_reg)(CPUARMState *env, void *rip, uint32_t value)
 275 {
 276     const ARMCPRegInfo *ri = rip;
 277     int excp = ri->writefn(env, ri, value);
 278     if (excp) {
 279         raise_exception(env, excp);
 280     }
 281 }
 282
 283 uint32_t HELPER(get_cp_reg)(CPUARMState *env, void *rip)
 284 {
 285     const ARMCPRegInfo *ri = rip;
 286     uint64_t value;
 287     int excp = ri->readfn(env, ri, &value);
 288     if (excp) {
 289         raise_exception(env, excp);
 290     }
 291     return value;
 292 }
 293
 294 void HELPER(set_cp_reg64)(CPUARMState *env, void *rip, uint64_t value)
 295 {
 296     const ARMCPRegInfo *ri = rip;
 297     int excp = ri->writefn(env, ri, value);
 298     if (excp) {
 299         raise_exception(env, excp);
 300     }
 301 }
 302
 303 uint64_t HELPER(get_cp_reg64)(CPUARMState *env, void *rip)
 304 {
 305     const ARMCPRegInfo *ri = rip;
 306     uint64_t value;
 307     int excp = ri->readfn(env, ri, &value);
 308     if (excp) {
 309         raise_exception(env, excp);
 310     }
 311     return value;
 312 }
 313
 314 /* ??? Flag setting arithmetic is awkward because we need to do comparisons.
 315    The only way to do that in TCG is a conditional branch, which clobbers
 316    all our temporaries.  For now implement these as helper functions.  */
 317
 318 uint32_t HELPER(sbc_cc)(CPUARMState *env, uint32_t a, uint32_t b)
 319 {
 320     uint32_t result;
 321     if (!env->CF) {
 322         result = a - b - 1;
 323         env->CF = a > b;
 324     } else {
 325         result = a - b;
 326         env->CF = a >= b;
 327     }
 328     env->VF = (a ^ b) & (a ^ result);
 329     env->NF = env->ZF = result;
 330     return result;
 331 }
 332
 333 /* Similarly for variable shift instructions.  */
 334
 335 uint32_t HELPER(shl_cc)(CPUARMState *env, uint32_t x, uint32_t i)
 336 {
 337     int shift = i & 0xff;
 338     if (shift >= 32) {
 339         if (shift == 32)
 340             env->CF = x & 1;
 341         else
 342             env->CF = 0;
 343         return 0;
 344     } else if (shift != 0) {
 345         env->CF = (x >> (32 - shift)) & 1;
 346         return x << shift;
 347     }
 348     return x;
 349 }
 350
 351 uint32_t HELPER(shr_cc)(CPUARMState *env, uint32_t x, uint32_t i)
 352 {
 353     int shift = i & 0xff;
 354     if (shift >= 32) {
 355         if (shift == 32)
 356             env->CF = (x >> 31) & 1;
 357         else
 358             env->CF = 0;
 359         return 0;
 360     } else if (shift != 0) {
 361         env->CF = (x >> (shift - 1)) & 1;
 362         return x >> shift;
 363     }
 364     return x;
 365 }
 366
 367 uint32_t HELPER(sar_cc)(CPUARMState *env, uint32_t x, uint32_t i)
 368 {
 369     int shift = i & 0xff;
 370     if (shift >= 32) {
 371         env->CF = (x >> 31) & 1;
 372         return (int32_t)x >> 31;
 373     } else if (shift != 0) {
 374         env->CF = (x >> (shift - 1)) & 1;
 375         return (int32_t)x >> shift;
 376     }
 377     return x;
 378 }
 379
 380 uint32_t HELPER(ror_cc)(CPUARMState *env, uint32_t x, uint32_t i)
 381 {
 382     int shift1, shift;
 383     shift1 = i & 0xff;
 384     shift = shift1 & 0x1f;
 385     if (shift == 0) {
 386         if (shift1 != 0)
 387             env->CF = (x >> 31) & 1;
 388         return x;
 389     } else {
 390         env->CF = (x >> (shift - 1)) & 1;
 391         return ((uint32_t)x >> shift) | (x << (32 - shift));
 392     }
 393 }