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 "softmmu_exec.h"
  56
  57 #define MMUSUFFIX _mmu
  58
  59 #define SHIFT 0
  60 #include "softmmu_template.h"
  61
  62 #define SHIFT 1
  63 #include "softmmu_template.h"
  64
  65 #define SHIFT 2
  66 #include "softmmu_template.h"
  67
  68 #define SHIFT 3
  69 #include "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     TranslationBlock *tb;
  78     int ret;
  79
  80     ret = cpu_arm_handle_mmu_fault(env, addr, is_write, mmu_idx);
  81     if (unlikely(ret)) {
  82         if (retaddr) {
  83             /* now we have a real cpu fault */
  84             tb = tb_find_pc(retaddr);
  85             if (tb) {
  86                 /* the PC is inside the translated code. It means that we have
  87                    a virtual CPU fault */
  88                 cpu_restore_state(tb, env, retaddr);
  89             }
  90         }
  91         raise_exception(env, env->exception_index);
  92     }
  93 }
  94 #endif
  95
  96 uint32_t HELPER(add_setq)(CPUARMState *env, uint32_t a, uint32_t b)
  97 {
  98     uint32_t res = a + b;
  99     if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT))
 100         env->QF = 1;
 101     return res;
 102 }
 103
 104 uint32_t HELPER(add_saturate)(CPUARMState *env, 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         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 110     }
 111     return res;
 112 }
 113
 114 uint32_t HELPER(sub_saturate)(CPUARMState *env, uint32_t a, uint32_t b)
 115 {
 116     uint32_t res = a - b;
 117     if (((res ^ a) & SIGNBIT) && ((a ^ b) & SIGNBIT)) {
 118         env->QF = 1;
 119         res = ~(((int32_t)a >> 31) ^ SIGNBIT);
 120     }
 121     return res;
 122 }
 123
 124 uint32_t HELPER(double_saturate)(CPUARMState *env, int32_t val)
 125 {
 126     uint32_t res;
 127     if (val >= 0x40000000) {
 128         res = ~SIGNBIT;
 129         env->QF = 1;
 130     } else if (val <= (int32_t)0xc0000000) {
 131         res = SIGNBIT;
 132         env->QF = 1;
 133     } else {
 134         res = val << 1;
 135     }
 136     return res;
 137 }
 138
 139 uint32_t HELPER(add_usaturate)(CPUARMState *env, uint32_t a, uint32_t b)
 140 {
 141     uint32_t res = a + b;
 142     if (res < a) {
 143         env->QF = 1;
 144         res = ~0;
 145     }
 146     return res;
 147 }
 148
 149 uint32_t HELPER(sub_usaturate)(CPUARMState *env, uint32_t a, uint32_t b)
 150 {
 151     uint32_t res = a - b;
 152     if (res > a) {
 153         env->QF = 1;
 154         res = 0;
 155     }
 156     return res;
 157 }
 158
 159 /* Signed saturation.  */
 160 static inline uint32_t do_ssat(CPUARMState *env, int32_t val, int shift)
 161 {
 162     int32_t top;
 163     uint32_t mask;
 164
 165     top = val >> shift;
 166     mask = (1u << shift) - 1;
 167     if (top > 0) {
 168         env->QF = 1;
 169         return mask;
 170     } else if (top < -1) {
 171         env->QF = 1;
 172         return ~mask;
 173     }
 174     return val;
 175 }
 176
 177 /* Unsigned saturation.  */
 178 static inline uint32_t do_usat(CPUARMState *env, int32_t val, int shift)
 179 {
 180     uint32_t max;
 181
 182     max = (1u << shift) - 1;
 183     if (val < 0) {
 184         env->QF = 1;
 185         return 0;
 186     } else if (val > max) {
 187         env->QF = 1;
 188         return max;
 189     }
 190     return val;
 191 }
 192
 193 /* Signed saturate.  */
 194 uint32_t HELPER(ssat)(CPUARMState *env, uint32_t x, uint32_t shift)
 195 {
 196     return do_ssat(env, x, shift);
 197 }
 198
 199 /* Dual halfword signed saturate.  */
 200 uint32_t HELPER(ssat16)(CPUARMState *env, uint32_t x, uint32_t shift)
 201 {
 202     uint32_t res;
 203
 204     res = (uint16_t)do_ssat(env, (int16_t)x, shift);
 205     res |= do_ssat(env, ((int32_t)x) >> 16, shift) << 16;
 206     return res;
 207 }
 208
 209 /* Unsigned saturate.  */
 210 uint32_t HELPER(usat)(CPUARMState *env, uint32_t x, uint32_t shift)
 211 {
 212     return do_usat(env, x, shift);
 213 }
 214
 215 /* Dual halfword unsigned saturate.  */
 216 uint32_t HELPER(usat16)(CPUARMState *env, uint32_t x, uint32_t shift)
 217 {
 218     uint32_t res;
 219
 220     res = (uint16_t)do_usat(env, (int16_t)x, shift);
 221     res |= do_usat(env, ((int32_t)x) >> 16, shift) << 16;
 222     return res;
 223 }
 224
 225 void HELPER(wfi)(CPUARMState *env)
 226 {
 227     env->exception_index = EXCP_HLT;
 228     env->halted = 1;
 229     cpu_loop_exit(env);
 230 }
 231
 232 void HELPER(exception)(CPUARMState *env, uint32_t excp)
 233 {
 234     env->exception_index = excp;
 235     cpu_loop_exit(env);
 236 }
 237
 238 uint32_t HELPER(cpsr_read)(CPUARMState *env)
 239 {
 240     return cpsr_read(env) & ~CPSR_EXEC;
 241 }
 242
 243 void HELPER(cpsr_write)(CPUARMState *env, uint32_t val, uint32_t mask)
 244 {
 245     cpsr_write(env, val, mask);
 246 }
 247
 248 /* Access to user mode registers from privileged modes.  */
 249 uint32_t HELPER(get_user_reg)(CPUARMState *env, uint32_t regno)
 250 {
 251     uint32_t val;
 252
 253     if (regno == 13) {
 254         val = env->banked_r13[0];
 255     } else if (regno == 14) {
 256         val = env->banked_r14[0];
 257     } else if (regno >= 8
 258                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 259         val = env->usr_regs[regno - 8];
 260     } else {
 261         val = env->regs[regno];
 262     }
 263     return val;
 264 }
 265
 266 void HELPER(set_user_reg)(CPUARMState *env, uint32_t regno, uint32_t val)
 267 {
 268     if (regno == 13) {
 269         env->banked_r13[0] = val;
 270     } else if (regno == 14) {
 271         env->banked_r14[0] = val;
 272     } else if (regno >= 8
 273                && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
 274         env->usr_regs[regno - 8] = val;
 275     } else {
 276         env->regs[regno] = val;
 277     }
 278 }
 279
 280 void HELPER(set_cp_reg)(CPUARMState *env, void *rip, uint32_t value)
 281 {
 282     const ARMCPRegInfo *ri = rip;
 283     int excp = ri->writefn(env, ri, value);
 284     if (excp) {
 285         raise_exception(env, excp);
 286     }
 287 }
 288
 289 uint32_t HELPER(get_cp_reg)(CPUARMState *env, void *rip)
 290 {
 291     const ARMCPRegInfo *ri = rip;
 292     uint64_t value;
 293     int excp = ri->readfn(env, ri, &value);
 294     if (excp) {
 295         raise_exception(env, excp);
 296     }
 297     return value;
 298 }
 299
 300 void HELPER(set_cp_reg64)(CPUARMState *env, void *rip, uint64_t value)
 301 {
 302     const ARMCPRegInfo *ri = rip;
 303     int excp = ri->writefn(env, ri, value);
 304     if (excp) {
 305         raise_exception(env, excp);
 306     }
 307 }
 308
 309 uint64_t HELPER(get_cp_reg64)(CPUARMState *env, void *rip)
 310 {
 311     const ARMCPRegInfo *ri = rip;
 312     uint64_t value;
 313     int excp = ri->readfn(env, ri, &value);
 314     if (excp) {
 315         raise_exception(env, excp);
 316     }
 317     return value;
 318 }
 319
 320 /* ??? Flag setting arithmetic is awkward because we need to do comparisons.
 321    The only way to do that in TCG is a conditional branch, which clobbers
 322    all our temporaries.  For now implement these as helper functions.  */
 323
 324 uint32_t HELPER(adc_cc)(CPUARMState *env, uint32_t a, uint32_t b)
 325 {
 326     uint32_t result;
 327     if (!env->CF) {
 328         result = a + b;
 329         env->CF = result < a;
 330     } else {
 331         result = a + b + 1;
 332         env->CF = result <= a;
 333     }
 334     env->VF = (a ^ b ^ -1) & (a ^ result);
 335     env->NF = env->ZF = result;
 336     return result;
 337 }
 338
 339 uint32_t HELPER(sbc_cc)(CPUARMState *env, uint32_t a, uint32_t b)
 340 {
 341     uint32_t result;
 342     if (!env->CF) {
 343         result = a - b - 1;
 344         env->CF = a > b;
 345     } else {
 346         result = a - b;
 347         env->CF = a >= b;
 348     }
 349     env->VF = (a ^ b) & (a ^ result);
 350     env->NF = env->ZF = result;
 351     return result;
 352 }
 353
 354 /* Similarly for variable shift instructions.  */
 355
 356 uint32_t HELPER(shl_cc)(CPUARMState *env, uint32_t x, uint32_t i)
 357 {
 358     int shift = i & 0xff;
 359     if (shift >= 32) {
 360         if (shift == 32)
 361             env->CF = x & 1;
 362         else
 363             env->CF = 0;
 364         return 0;
 365     } else if (shift != 0) {
 366         env->CF = (x >> (32 - shift)) & 1;
 367         return x << shift;
 368     }
 369     return x;
 370 }
 371
 372 uint32_t HELPER(shr_cc)(CPUARMState *env, uint32_t x, uint32_t i)
 373 {
 374     int shift = i & 0xff;
 375     if (shift >= 32) {
 376         if (shift == 32)
 377             env->CF = (x >> 31) & 1;
 378         else
 379             env->CF = 0;
 380         return 0;
 381     } else if (shift != 0) {
 382         env->CF = (x >> (shift - 1)) & 1;
 383         return x >> shift;
 384     }
 385     return x;
 386 }
 387
 388 uint32_t HELPER(sar_cc)(CPUARMState *env, uint32_t x, uint32_t i)
 389 {
 390     int shift = i & 0xff;
 391     if (shift >= 32) {
 392         env->CF = (x >> 31) & 1;
 393         return (int32_t)x >> 31;
 394     } else if (shift != 0) {
 395         env->CF = (x >> (shift - 1)) & 1;
 396         return (int32_t)x >> shift;
 397     }
 398     return x;
 399 }
 400
 401 uint32_t HELPER(ror_cc)(CPUARMState *env, uint32_t x, uint32_t i)
 402 {
 403     int shift1, shift;
 404     shift1 = i & 0xff;
 405     shift = shift1 & 0x1f;
 406     if (shift == 0) {
 407         if (shift1 != 0)
 408             env->CF = (x >> 31) & 1;
 409         return x;
 410     } else {
 411         env->CF = (x >> (shift - 1)) & 1;
 412         return ((uint32_t)x >> shift) | (x << (32 - shift));
 413     }
 414 }