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 2.1 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 "qemu/osdep.h"
  21 #include "cpu.h"
  22 #include "exec/exec-all.h"
  23 #include "qemu/timer.h"
  24 #include "qemu/host-utils.h"
  25 #include "exec/helper-proto.h"
  26
  27 void cpu_raise_exception_ra(CPUSPARCState *env, int tt, uintptr_t ra)
  28 {
  29     CPUState *cs = env_cpu(env);
  30
  31     cs->exception_index = tt;
  32     cpu_loop_exit_restore(cs, ra);
  33 }
  34
  35 void helper_raise_exception(CPUSPARCState *env, int tt)
  36 {
  37     CPUState *cs = env_cpu(env);
  38
  39     cs->exception_index = tt;
  40     cpu_loop_exit(cs);
  41 }
  42
  43 void helper_debug(CPUSPARCState *env)
  44 {
  45     CPUState *cs = env_cpu(env);
  46
  47     cs->exception_index = EXCP_DEBUG;
  48     cpu_loop_exit(cs);
  49 }
  50
  51 #ifdef TARGET_SPARC64
  52 void helper_tick_set_count(void *opaque, uint64_t count)
  53 {
  54 #if !defined(CONFIG_USER_ONLY)
  55     cpu_tick_set_count(opaque, count);
  56 #endif
  57 }
  58
  59 uint64_t helper_tick_get_count(CPUSPARCState *env, void *opaque, int mem_idx)
  60 {
  61 #if !defined(CONFIG_USER_ONLY)
  62     CPUTimer *timer = opaque;
  63
  64     if (timer->npt && mem_idx < MMU_KERNEL_IDX) {
  65         cpu_raise_exception_ra(env, TT_PRIV_INSN, GETPC());
  66     }
  67
  68     return cpu_tick_get_count(timer);
  69 #else
  70     /* In user-mode, QEMU_CLOCK_VIRTUAL doesn't exist.
  71        Just pass through the host cpu clock ticks.  */
  72     return cpu_get_host_ticks();
  73 #endif
  74 }
  75
  76 void helper_tick_set_limit(void *opaque, uint64_t limit)
  77 {
  78 #if !defined(CONFIG_USER_ONLY)
  79     cpu_tick_set_limit(opaque, limit);
  80 #endif
  81 }
  82 #endif
  83
  84 static target_ulong do_udiv(CPUSPARCState *env, target_ulong a,
  85                             target_ulong b, int cc, uintptr_t ra)
  86 {
  87     int overflow = 0;
  88     uint64_t x0;
  89     uint32_t x1;
  90
  91     x0 = (a & 0xffffffff) | ((int64_t) (env->y) << 32);
  92     x1 = (b & 0xffffffff);
  93
  94     if (x1 == 0) {
  95         cpu_raise_exception_ra(env, TT_DIV_ZERO, ra);
  96     }
  97
  98     x0 = x0 / x1;
  99     if (x0 > UINT32_MAX) {
 100         x0 = UINT32_MAX;
 101         overflow = 1;
 102     }
 103
 104     if (cc) {
 105         env->cc_dst = x0;
 106         env->cc_src2 = overflow;
 107         env->cc_op = CC_OP_DIV;
 108     }
 109     return x0;
 110 }
 111
 112 target_ulong helper_udiv(CPUSPARCState *env, target_ulong a, target_ulong b)
 113 {
 114     return do_udiv(env, a, b, 0, GETPC());
 115 }
 116
 117 target_ulong helper_udiv_cc(CPUSPARCState *env, target_ulong a, target_ulong b)
 118 {
 119     return do_udiv(env, a, b, 1, GETPC());
 120 }
 121
 122 static target_ulong do_sdiv(CPUSPARCState *env, target_ulong a,
 123                             target_ulong b, int cc, uintptr_t ra)
 124 {
 125     int overflow = 0;
 126     int64_t x0;
 127     int32_t x1;
 128
 129     x0 = (a & 0xffffffff) | ((int64_t) (env->y) << 32);
 130     x1 = (b & 0xffffffff);
 131
 132     if (x1 == 0) {
 133         cpu_raise_exception_ra(env, TT_DIV_ZERO, ra);
 134     } else if (x1 == -1 && x0 == INT64_MIN) {
 135         x0 = INT32_MAX;
 136         overflow = 1;
 137     } else {
 138         x0 = x0 / x1;
 139         if ((int32_t) x0 != x0) {
 140             x0 = x0 < 0 ? INT32_MIN : INT32_MAX;
 141             overflow = 1;
 142         }
 143     }
 144
 145     if (cc) {
 146         env->cc_dst = x0;
 147         env->cc_src2 = overflow;
 148         env->cc_op = CC_OP_DIV;
 149     }
 150     return x0;
 151 }
 152
 153 target_ulong helper_sdiv(CPUSPARCState *env, target_ulong a, target_ulong b)
 154 {
 155     return do_sdiv(env, a, b, 0, GETPC());
 156 }
 157
 158 target_ulong helper_sdiv_cc(CPUSPARCState *env, target_ulong a, target_ulong b)
 159 {
 160     return do_sdiv(env, a, b, 1, GETPC());
 161 }
 162
 163 #ifdef TARGET_SPARC64
 164 int64_t helper_sdivx(CPUSPARCState *env, int64_t a, int64_t b)
 165 {
 166     if (b == 0) {
 167         /* Raise divide by zero trap.  */
 168         cpu_raise_exception_ra(env, TT_DIV_ZERO, GETPC());
 169     } else if (b == -1) {
 170         /* Avoid overflow trap with i386 divide insn.  */
 171         return -a;
 172     } else {
 173         return a / b;
 174     }
 175 }
 176
 177 uint64_t helper_udivx(CPUSPARCState *env, uint64_t a, uint64_t b)
 178 {
 179     if (b == 0) {
 180         /* Raise divide by zero trap.  */
 181         cpu_raise_exception_ra(env, TT_DIV_ZERO, GETPC());
 182     }
 183     return a / b;
 184 }
 185 #endif
 186
 187 target_ulong helper_taddcctv(CPUSPARCState *env, target_ulong src1,
 188                              target_ulong src2)
 189 {
 190     target_ulong dst;
 191
 192     /* Tag overflow occurs if either input has bits 0 or 1 set.  */
 193     if ((src1 | src2) & 3) {
 194         goto tag_overflow;
 195     }
 196
 197     dst = src1 + src2;
 198
 199     /* Tag overflow occurs if the addition overflows.  */
 200     if (~(src1 ^ src2) & (src1 ^ dst) & (1u << 31)) {
 201         goto tag_overflow;
 202     }
 203
 204     /* Only modify the CC after any exceptions have been generated.  */
 205     env->cc_op = CC_OP_TADDTV;
 206     env->cc_src = src1;
 207     env->cc_src2 = src2;
 208     env->cc_dst = dst;
 209     return dst;
 210
 211  tag_overflow:
 212     cpu_raise_exception_ra(env, TT_TOVF, GETPC());
 213 }
 214
 215 target_ulong helper_tsubcctv(CPUSPARCState *env, target_ulong src1,
 216                              target_ulong src2)
 217 {
 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_raise_exception_ra(env, TT_TOVF, GETPC());
 241 }
 242
 243 #ifndef TARGET_SPARC64
 244 void helper_power_down(CPUSPARCState *env)
 245 {
 246     CPUState *cs = env_cpu(env);
 247
 248     cs->halted = 1;
 249     cs->exception_index = EXCP_HLT;
 250     env->pc = env->npc;
 251     env->npc = env->pc + 4;
 252     cpu_loop_exit(cs);
 253 }
 254 #endif