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 #if HOST_LONG_BITS == 64 && defined(__GNUC__)
 101         /* assuming 64-bit hosts have __uint128_t */
 102         __uint128_t a = ((__uint128_t)ah << 64) | al;
 103         __uint128_t q = a / b;
 104         env->retxl = a % b;
 105         ret = q;
 106         if (ret != q) {
 107             runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
 108         }
 109 #else
 110         /* 32-bit hosts would need special wrapper functionality - just abort if
 111            we encounter such a case; it's very unlikely anyways. */
 112         cpu_abort(env, "128 -> 64/64 division not implemented\n");
 113 #endif
 114     }
 115     return ret;
 116 }
 117
 118 /* absolute value 32-bit */
 119 uint32_t HELPER(abs_i32)(int32_t val)
 120 {
 121     if (val < 0) {
 122         return -val;
 123     } else {
 124         return val;
 125     }
 126 }
 127
 128 /* negative absolute value 32-bit */
 129 int32_t HELPER(nabs_i32)(int32_t val)
 130 {
 131     if (val < 0) {
 132         return val;
 133     } else {
 134         return -val;
 135     }
 136 }
 137
 138 /* absolute value 64-bit */
 139 uint64_t HELPER(abs_i64)(int64_t val)
 140 {
 141     HELPER_LOG("%s: val 0x%" PRIx64 "\n", __func__, val);
 142
 143     if (val < 0) {
 144         return -val;
 145     } else {
 146         return val;
 147     }
 148 }
 149
 150 /* negative absolute value 64-bit */
 151 int64_t HELPER(nabs_i64)(int64_t val)
 152 {
 153     if (val < 0) {
 154         return val;
 155     } else {
 156         return -val;
 157     }
 158 }
 159
 160 /* count leading zeros, for find leftmost one */
 161 uint64_t HELPER(clz)(uint64_t v)
 162 {
 163     return clz64(v);
 164 }
 165
 166 uint64_t HELPER(cvd)(int32_t bin)
 167 {
 168     /* positive 0 */
 169     uint64_t dec = 0x0c;
 170     int shift = 4;
 171
 172     if (bin < 0) {
 173         bin = -bin;
 174         dec = 0x0d;
 175     }
 176
 177     for (shift = 4; (shift < 64) && bin; shift += 4) {
 178         int current_number = bin % 10;
 179
 180         dec |= (current_number) << shift;
 181         bin /= 10;
 182     }
 183
 184     return dec;
 185 }
 186
 187 uint64_t HELPER(popcnt)(uint64_t r2)
 188 {
 189     uint64_t ret = 0;
 190     int i;
 191
 192     for (i = 0; i < 64; i += 8) {
 193         uint64_t t = ctpop32((r2 >> i) & 0xff);
 194         ret |= t << i;
 195     }
 196     return ret;
 197 }