qemu/target/sparc/helper.c
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   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
  27void 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
  35void 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
  43void 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
  52void 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
  59uint64_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
  76void 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
  84static 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
 112target_ulong helper_udiv(CPUSPARCState *env, target_ulong a, target_ulong b)
 113{
 114    return do_udiv(env, a, b, 0, GETPC());
 115}
 116
 117target_ulong helper_udiv_cc(CPUSPARCState *env, target_ulong a, target_ulong b)
 118{
 119    return do_udiv(env, a, b, 1, GETPC());
 120}
 121
 122static 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
 153target_ulong helper_sdiv(CPUSPARCState *env, target_ulong a, target_ulong b)
 154{
 155    return do_sdiv(env, a, b, 0, GETPC());
 156}
 157
 158target_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
 164int64_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
 177uint64_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
 187target_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
 215target_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
 244void 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
 255