target-s390x/int_helper.c

   1 /*
   2  *  S/390 integer helper routines
   3  *
   4  *  Copyright (c) 2009 Ulrich Hecht
   5  *  Copyright (c) 2009 Alexander Graf
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "cpu.h"
  22 #include "qemu/host-utils.h"
  23 #include "helper.h"
  24
  25 /* #define DEBUG_HELPER */
  26 #ifdef DEBUG_HELPER
  27 #define HELPER_LOG(x...) qemu_log(x)
  28 #else
  29 #define HELPER_LOG(x...)
  30 #endif
  31
  32 /* 64/32 -> 32 signed division */
  33 int64_t HELPER(divs32)(CPUS390XState *env, int64_t a, int64_t b64)
  34 {
  35     int32_t ret, b = b64;
  36     int64_t q;
  37
  38     if (b == 0) {
  39         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  40     }
  41
  42     ret = q = a / b;
  43     env->retxl = a % b;
  44
  45     /* Catch non-representable quotient.  */
  46     if (ret != q) {
  47         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  48     }
  49
  50     return ret;
  51 }
  52
  53 /* 64/32 -> 32 unsigned division */
  54 uint64_t HELPER(divu32)(CPUS390XState *env, uint64_t a, uint64_t b64)
  55 {
  56     uint32_t ret, b = b64;
  57     uint64_t q;
  58
  59     if (b == 0) {
  60         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  61     }
  62
  63     ret = q = a / b;
  64     env->retxl = a % b;
  65
  66     /* Catch non-representable quotient.  */
  67     if (ret != q) {
  68         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  69     }
  70
  71     return ret;
  72 }
  73
  74 /* 64/64 -> 64 signed division */
  75 int64_t HELPER(divs64)(CPUS390XState *env, int64_t a, int64_t b)
  76 {
  77     /* Catch divide by zero, and non-representable quotient (MIN / -1).  */
  78     if (b == 0 || (b == -1 && a == (1ll << 63))) {
  79         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  80     }
  81     env->retxl = a % b;
  82     return a / b;
  83 }
  84
  85 /* 128 -> 64/64 unsigned division */
  86 uint64_t HELPER(divu64)(CPUS390XState *env, uint64_t ah, uint64_t al,
  87                         uint64_t b)
  88 {
  89     uint64_t ret;
  90     /* Signal divide by zero.  */
  91     if (b == 0) {
  92         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  93     }
  94     if (ah == 0) {
  95         /* 64 -> 64/64 case */
  96         env->retxl = al % b;
  97         ret = al / b;
  98     } else {
  99         /* ??? Move i386 idivq helper to host-utils.  */
 100 #ifdef CONFIG_INT128
 101         __uint128_t a = ((__uint128_t)ah << 64) | al;
 102         __uint128_t q = a / b;
 103         env->retxl = a % b;
 104         ret = q;
 105         if (ret != q) {
 106             runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
 107         }
 108 #else
 109         /* 32-bit hosts would need special wrapper functionality - just abort if
 110            we encounter such a case; it's very unlikely anyways. */
 111         cpu_abort(env, "128 -> 64/64 division not implemented\n");
 112 #endif
 113     }
 114     return ret;
 115 }
 116
 117 /* absolute value 32-bit */
 118 uint32_t HELPER(abs_i32)(int32_t val)
 119 {
 120     if (val < 0) {
 121         return -val;
 122     } else {
 123         return val;
 124     }
 125 }
 126
 127 /* negative absolute value 32-bit */
 128 int32_t HELPER(nabs_i32)(int32_t val)
 129 {
 130     if (val < 0) {
 131         return val;
 132     } else {
 133         return -val;
 134     }
 135 }
 136
 137 /* absolute value 64-bit */
 138 uint64_t HELPER(abs_i64)(int64_t val)
 139 {
 140     HELPER_LOG("%s: val 0x%" PRIx64 "\n", __func__, val);
 141
 142     if (val < 0) {
 143         return -val;
 144     } else {
 145         return val;
 146     }
 147 }
 148
 149 /* negative absolute value 64-bit */
 150 int64_t HELPER(nabs_i64)(int64_t val)
 151 {
 152     if (val < 0) {
 153         return val;
 154     } else {
 155         return -val;
 156     }
 157 }
 158
 159 /* count leading zeros, for find leftmost one */
 160 uint64_t HELPER(clz)(uint64_t v)
 161 {
 162     return clz64(v);
 163 }
 164
 165 uint64_t HELPER(cvd)(int32_t bin)
 166 {
 167     /* positive 0 */
 168     uint64_t dec = 0x0c;
 169     int shift = 4;
 170
 171     if (bin < 0) {
 172         bin = -bin;
 173         dec = 0x0d;
 174     }
 175
 176     for (shift = 4; (shift < 64) && bin; shift += 4) {
 177         int current_number = bin % 10;
 178
 179         dec |= (current_number) << shift;
 180         bin /= 10;
 181     }
 182
 183     return dec;
 184 }
 185
 186 uint64_t HELPER(popcnt)(uint64_t r2)
 187 {
 188     uint64_t ret = 0;
 189     int i;
 190
 191     for (i = 0; i < 64; i += 8) {
 192         uint64_t t = ctpop32((r2 >> i) & 0xff);
 193         ret |= t << i;
 194     }
 195     return ret;
 196 }