target-sparc/helper.c

   1 /*
   2  *  Misc Sparc helpers
   3  *
   4  *  Copyright (c) 2003-2005 Fabrice Bellard
   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
  20 #include "cpu.h"
  21 #include "qemu/host-utils.h"
  22 #include "helper.h"
  23 #include "sysemu/sysemu.h"
  24
  25 void helper_raise_exception(CPUSPARCState *env, int tt)
  26 {
  27     CPUState *cs = CPU(sparc_env_get_cpu(env));
  28
  29     cs->exception_index = tt;
  30     cpu_loop_exit(cs);
  31 }
  32
  33 void helper_debug(CPUSPARCState *env)
  34 {
  35     CPUState *cs = CPU(sparc_env_get_cpu(env));
  36
  37     cs->exception_index = EXCP_DEBUG;
  38     cpu_loop_exit(cs);
  39 }
  40
  41 #ifdef TARGET_SPARC64
  42 target_ulong helper_popc(target_ulong val)
  43 {
  44     return ctpop64(val);
  45 }
  46
  47 void helper_tick_set_count(void *opaque, uint64_t count)
  48 {
  49 #if !defined(CONFIG_USER_ONLY)
  50     cpu_tick_set_count(opaque, count);
  51 #endif
  52 }
  53
  54 uint64_t helper_tick_get_count(void *opaque)
  55 {
  56 #if !defined(CONFIG_USER_ONLY)
  57     return cpu_tick_get_count(opaque);
  58 #else
  59     return 0;
  60 #endif
  61 }
  62
  63 void helper_tick_set_limit(void *opaque, uint64_t limit)
  64 {
  65 #if !defined(CONFIG_USER_ONLY)
  66     cpu_tick_set_limit(opaque, limit);
  67 #endif
  68 }
  69 #endif
  70
  71 static target_ulong helper_udiv_common(CPUSPARCState *env, target_ulong a,
  72                                        target_ulong b, int cc)
  73 {
  74     SPARCCPU *cpu = sparc_env_get_cpu(env);
  75     int overflow = 0;
  76     uint64_t x0;
  77     uint32_t x1;
  78
  79     x0 = (a & 0xffffffff) | ((int64_t) (env->y) << 32);
  80     x1 = (b & 0xffffffff);
  81
  82     if (x1 == 0) {
  83         cpu_restore_state(CPU(cpu), GETPC());
  84         helper_raise_exception(env, TT_DIV_ZERO);
  85     }
  86
  87     x0 = x0 / x1;
  88     if (x0 > UINT32_MAX) {
  89         x0 = UINT32_MAX;
  90         overflow = 1;
  91     }
  92
  93     if (cc) {
  94         env->cc_dst = x0;
  95         env->cc_src2 = overflow;
  96         env->cc_op = CC_OP_DIV;
  97     }
  98     return x0;
  99 }
 100
 101 target_ulong helper_udiv(CPUSPARCState *env, target_ulong a, target_ulong b)
 102 {
 103     return helper_udiv_common(env, a, b, 0);
 104 }
 105
 106 target_ulong helper_udiv_cc(CPUSPARCState *env, target_ulong a, target_ulong b)
 107 {
 108     return helper_udiv_common(env, a, b, 1);
 109 }
 110
 111 static target_ulong helper_sdiv_common(CPUSPARCState *env, target_ulong a,
 112                                        target_ulong b, int cc)
 113 {
 114     SPARCCPU *cpu = sparc_env_get_cpu(env);
 115     int overflow = 0;
 116     int64_t x0;
 117     int32_t x1;
 118
 119     x0 = (a & 0xffffffff) | ((int64_t) (env->y) << 32);
 120     x1 = (b & 0xffffffff);
 121
 122     if (x1 == 0) {
 123         cpu_restore_state(CPU(cpu), GETPC());
 124         helper_raise_exception(env, TT_DIV_ZERO);
 125     } else if (x1 == -1 && x0 == INT64_MIN) {
 126         x0 = INT32_MAX;
 127         overflow = 1;
 128     } else {
 129         x0 = x0 / x1;
 130         if ((int32_t) x0 != x0) {
 131             x0 = x0 < 0 ? INT32_MIN : INT32_MAX;
 132             overflow = 1;
 133         }
 134     }
 135
 136     if (cc) {
 137         env->cc_dst = x0;
 138         env->cc_src2 = overflow;
 139         env->cc_op = CC_OP_DIV;
 140     }
 141     return x0;
 142 }
 143
 144 target_ulong helper_sdiv(CPUSPARCState *env, target_ulong a, target_ulong b)
 145 {
 146     return helper_sdiv_common(env, a, b, 0);
 147 }
 148
 149 target_ulong helper_sdiv_cc(CPUSPARCState *env, target_ulong a, target_ulong b)
 150 {
 151     return helper_sdiv_common(env, a, b, 1);
 152 }
 153
 154 #ifdef TARGET_SPARC64
 155 int64_t helper_sdivx(CPUSPARCState *env, int64_t a, int64_t b)
 156 {
 157     if (b == 0) {
 158         /* Raise divide by zero trap.  */
 159         SPARCCPU *cpu = sparc_env_get_cpu(env);
 160
 161         cpu_restore_state(CPU(cpu), GETPC());
 162         helper_raise_exception(env, TT_DIV_ZERO);
 163     } else if (b == -1) {
 164         /* Avoid overflow trap with i386 divide insn.  */
 165         return -a;
 166     } else {
 167         return a / b;
 168     }
 169 }
 170
 171 uint64_t helper_udivx(CPUSPARCState *env, uint64_t a, uint64_t b)
 172 {
 173     if (b == 0) {
 174         /* Raise divide by zero trap.  */
 175         SPARCCPU *cpu = sparc_env_get_cpu(env);
 176
 177         cpu_restore_state(CPU(cpu), GETPC());
 178         helper_raise_exception(env, TT_DIV_ZERO);
 179     }
 180     return a / b;
 181 }
 182 #endif
 183
 184 target_ulong helper_taddcctv(CPUSPARCState *env, target_ulong src1,
 185                              target_ulong src2)
 186 {
 187     SPARCCPU *cpu = sparc_env_get_cpu(env);
 188     target_ulong dst;
 189
 190     /* Tag overflow occurs if either input has bits 0 or 1 set.  */
 191     if ((src1 | src2) & 3) {
 192         goto tag_overflow;
 193     }
 194
 195     dst = src1 + src2;
 196
 197     /* Tag overflow occurs if the addition overflows.  */
 198     if (~(src1 ^ src2) & (src1 ^ dst) & (1u << 31)) {
 199         goto tag_overflow;
 200     }
 201
 202     /* Only modify the CC after any exceptions have been generated.  */
 203     env->cc_op = CC_OP_TADDTV;
 204     env->cc_src = src1;
 205     env->cc_src2 = src2;
 206     env->cc_dst = dst;
 207     return dst;
 208
 209  tag_overflow:
 210     cpu_restore_state(CPU(cpu), GETPC());
 211     helper_raise_exception(env, TT_TOVF);
 212 }
 213
 214 target_ulong helper_tsubcctv(CPUSPARCState *env, target_ulong src1,
 215                              target_ulong src2)
 216 {
 217     SPARCCPU *cpu = sparc_env_get_cpu(env);
 218     target_ulong dst;
 219
 220     /* Tag overflow occurs if either input has bits 0 or 1 set.  */
 221     if ((src1 | src2) & 3) {
 222         goto tag_overflow;
 223     }
 224
 225     dst = src1 - src2;
 226
 227     /* Tag overflow occurs if the subtraction overflows.  */
 228     if ((src1 ^ src2) & (src1 ^ dst) & (1u << 31)) {
 229         goto tag_overflow;
 230     }
 231
 232     /* Only modify the CC after any exceptions have been generated.  */
 233     env->cc_op = CC_OP_TSUBTV;
 234     env->cc_src = src1;
 235     env->cc_src2 = src2;
 236     env->cc_dst = dst;
 237     return dst;
 238
 239  tag_overflow:
 240     cpu_restore_state(CPU(cpu), GETPC());
 241     helper_raise_exception(env, TT_TOVF);
 242 }
 243
 244 #ifndef TARGET_SPARC64
 245 void helper_power_down(CPUSPARCState *env)
 246 {
 247     CPUState *cs = CPU(sparc_env_get_cpu(env));
 248
 249     cs->halted = 1;
 250     cs->exception_index = EXCP_HLT;
 251     env->pc = env->npc;
 252     env->npc = env->pc + 4;
 253     cpu_loop_exit(cs);
 254 }
 255 #endif