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     env->exception_index = tt;
  28     cpu_loop_exit(env);
  29 }
  30
  31 void helper_debug(CPUSPARCState *env)
  32 {
  33     env->exception_index = EXCP_DEBUG;
  34     cpu_loop_exit(env);
  35 }
  36
  37 #ifdef TARGET_SPARC64
  38 target_ulong helper_popc(target_ulong val)
  39 {
  40     return ctpop64(val);
  41 }
  42
  43 void helper_tick_set_count(void *opaque, uint64_t count)
  44 {
  45 #if !defined(CONFIG_USER_ONLY)
  46     cpu_tick_set_count(opaque, count);
  47 #endif
  48 }
  49
  50 uint64_t helper_tick_get_count(void *opaque)
  51 {
  52 #if !defined(CONFIG_USER_ONLY)
  53     return cpu_tick_get_count(opaque);
  54 #else
  55     return 0;
  56 #endif
  57 }
  58
  59 void helper_tick_set_limit(void *opaque, uint64_t limit)
  60 {
  61 #if !defined(CONFIG_USER_ONLY)
  62     cpu_tick_set_limit(opaque, limit);
  63 #endif
  64 }
  65 #endif
  66
  67 static target_ulong helper_udiv_common(CPUSPARCState *env, target_ulong a,
  68                                        target_ulong b, int cc)
  69 {
  70     int overflow = 0;
  71     uint64_t x0;
  72     uint32_t x1;
  73
  74     x0 = (a & 0xffffffff) | ((int64_t) (env->y) << 32);
  75     x1 = (b & 0xffffffff);
  76
  77     if (x1 == 0) {
  78         cpu_restore_state(env, GETPC());
  79         helper_raise_exception(env, TT_DIV_ZERO);
  80     }
  81
  82     x0 = x0 / x1;
  83     if (x0 > 0xffffffff) {
  84         x0 = 0xffffffff;
  85         overflow = 1;
  86     }
  87
  88     if (cc) {
  89         env->cc_dst = x0;
  90         env->cc_src2 = overflow;
  91         env->cc_op = CC_OP_DIV;
  92     }
  93     return x0;
  94 }
  95
  96 target_ulong helper_udiv(CPUSPARCState *env, target_ulong a, target_ulong b)
  97 {
  98     return helper_udiv_common(env, a, b, 0);
  99 }
 100
 101 target_ulong helper_udiv_cc(CPUSPARCState *env, target_ulong a, target_ulong b)
 102 {
 103     return helper_udiv_common(env, a, b, 1);
 104 }
 105
 106 static target_ulong helper_sdiv_common(CPUSPARCState *env, target_ulong a,
 107                                        target_ulong b, int cc)
 108 {
 109     int overflow = 0;
 110     int64_t x0;
 111     int32_t x1;
 112
 113     x0 = (a & 0xffffffff) | ((int64_t) (env->y) << 32);
 114     x1 = (b & 0xffffffff);
 115
 116     if (x1 == 0) {
 117         cpu_restore_state(env, GETPC());
 118         helper_raise_exception(env, TT_DIV_ZERO);
 119     }
 120
 121     x0 = x0 / x1;
 122     if ((int32_t) x0 != x0) {
 123         x0 = x0 < 0 ? 0x80000000 : 0x7fffffff;
 124         overflow = 1;
 125     }
 126
 127     if (cc) {
 128         env->cc_dst = x0;
 129         env->cc_src2 = overflow;
 130         env->cc_op = CC_OP_DIV;
 131     }
 132     return x0;
 133 }
 134
 135 target_ulong helper_sdiv(CPUSPARCState *env, target_ulong a, target_ulong b)
 136 {
 137     return helper_sdiv_common(env, a, b, 0);
 138 }
 139
 140 target_ulong helper_sdiv_cc(CPUSPARCState *env, target_ulong a, target_ulong b)
 141 {
 142     return helper_sdiv_common(env, a, b, 1);
 143 }
 144
 145 #ifdef TARGET_SPARC64
 146 int64_t helper_sdivx(CPUSPARCState *env, int64_t a, int64_t b)
 147 {
 148     if (b == 0) {
 149         /* Raise divide by zero trap.  */
 150         cpu_restore_state(env, GETPC());
 151         helper_raise_exception(env, TT_DIV_ZERO);
 152     } else if (b == -1) {
 153         /* Avoid overflow trap with i386 divide insn.  */
 154         return -a;
 155     } else {
 156         return a / b;
 157     }
 158 }
 159
 160 uint64_t helper_udivx(CPUSPARCState *env, uint64_t a, uint64_t b)
 161 {
 162     if (b == 0) {
 163         /* Raise divide by zero trap.  */
 164         cpu_restore_state(env, GETPC());
 165         helper_raise_exception(env, TT_DIV_ZERO);
 166     }
 167     return a / b;
 168 }
 169 #endif
 170
 171 target_ulong helper_taddcctv(CPUSPARCState *env, target_ulong src1,
 172                              target_ulong src2)
 173 {
 174     target_ulong dst;
 175
 176     /* Tag overflow occurs if either input has bits 0 or 1 set.  */
 177     if ((src1 | src2) & 3) {
 178         goto tag_overflow;
 179     }
 180
 181     dst = src1 + src2;
 182
 183     /* Tag overflow occurs if the addition overflows.  */
 184     if (~(src1 ^ src2) & (src1 ^ dst) & (1u << 31)) {
 185         goto tag_overflow;
 186     }
 187
 188     /* Only modify the CC after any exceptions have been generated.  */
 189     env->cc_op = CC_OP_TADDTV;
 190     env->cc_src = src1;
 191     env->cc_src2 = src2;
 192     env->cc_dst = dst;
 193     return dst;
 194
 195  tag_overflow:
 196     cpu_restore_state(env, GETPC());
 197     helper_raise_exception(env, TT_TOVF);
 198 }
 199
 200 target_ulong helper_tsubcctv(CPUSPARCState *env, target_ulong src1,
 201                              target_ulong src2)
 202 {
 203     target_ulong dst;
 204
 205     /* Tag overflow occurs if either input has bits 0 or 1 set.  */
 206     if ((src1 | src2) & 3) {
 207         goto tag_overflow;
 208     }
 209
 210     dst = src1 - src2;
 211
 212     /* Tag overflow occurs if the subtraction overflows.  */
 213     if ((src1 ^ src2) & (src1 ^ dst) & (1u << 31)) {
 214         goto tag_overflow;
 215     }
 216
 217     /* Only modify the CC after any exceptions have been generated.  */
 218     env->cc_op = CC_OP_TSUBTV;
 219     env->cc_src = src1;
 220     env->cc_src2 = src2;
 221     env->cc_dst = dst;
 222     return dst;
 223
 224  tag_overflow:
 225     cpu_restore_state(env, GETPC());
 226     helper_raise_exception(env, TT_TOVF);
 227 }