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 /* 64/64 -> 128 unsigned multiplication */
  33 uint64_t HELPER(mul128)(CPUS390XState *env, uint64_t v1, uint64_t v2)
  34 {
  35     uint64_t reth;
  36     mulu64(&env->retxl, &reth, v1, v2);
  37     return reth;
  38 }
  39
  40 /* 64/32 -> 32 signed division */
  41 int64_t HELPER(divs32)(CPUS390XState *env, int64_t a, int64_t b64)
  42 {
  43     int32_t ret, b = b64;
  44     int64_t q;
  45
  46     if (b == 0) {
  47         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  48     }
  49
  50     ret = q = a / b;
  51     env->retxl = a % b;
  52
  53     /* Catch non-representable quotient.  */
  54     if (ret != q) {
  55         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  56     }
  57
  58     return ret;
  59 }
  60
  61 /* 64/32 -> 32 unsigned division */
  62 uint64_t HELPER(divu32)(CPUS390XState *env, uint64_t a, uint64_t b64)
  63 {
  64     uint32_t ret, b = b64;
  65     uint64_t q;
  66
  67     if (b == 0) {
  68         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  69     }
  70
  71     ret = q = a / b;
  72     env->retxl = a % b;
  73
  74     /* Catch non-representable quotient.  */
  75     if (ret != q) {
  76         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  77     }
  78
  79     return ret;
  80 }
  81
  82 /* 64/64 -> 64 signed division */
  83 int64_t HELPER(divs64)(CPUS390XState *env, int64_t a, int64_t b)
  84 {
  85     /* Catch divide by zero, and non-representable quotient (MIN / -1).  */
  86     if (b == 0 || (b == -1 && a == (1ll << 63))) {
  87         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  88     }
  89     env->retxl = a % b;
  90     return a / b;
  91 }
  92
  93 /* 128 -> 64/64 unsigned division */
  94 uint64_t HELPER(divu64)(CPUS390XState *env, uint64_t ah, uint64_t al,
  95                         uint64_t b)
  96 {
  97     uint64_t ret;
  98     /* Signal divide by zero.  */
  99     if (b == 0) {
 100         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
 101     }
 102     if (ah == 0) {
 103         /* 64 -> 64/64 case */
 104         env->retxl = al % b;
 105         ret = al / b;
 106     } else {
 107         /* ??? Move i386 idivq helper to host-utils.  */
 108 #if HOST_LONG_BITS == 64 && defined(__GNUC__)
 109         /* assuming 64-bit hosts have __uint128_t */
 110         __uint128_t a = ((__uint128_t)ah << 64) | al;
 111         __uint128_t q = a / b;
 112         env->retxl = a % b;
 113         ret = q;
 114         if (ret != q) {
 115             runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
 116         }
 117 #else
 118         /* 32-bit hosts would need special wrapper functionality - just abort if
 119            we encounter such a case; it's very unlikely anyways. */
 120         cpu_abort(env, "128 -> 64/64 division not implemented\n");
 121 #endif
 122     }
 123     return ret;
 124 }
 125
 126 /* absolute value 32-bit */
 127 uint32_t HELPER(abs_i32)(int32_t val)
 128 {
 129     if (val < 0) {
 130         return -val;
 131     } else {
 132         return val;
 133     }
 134 }
 135
 136 /* negative absolute value 32-bit */
 137 int32_t HELPER(nabs_i32)(int32_t val)
 138 {
 139     if (val < 0) {
 140         return val;
 141     } else {
 142         return -val;
 143     }
 144 }
 145
 146 /* absolute value 64-bit */
 147 uint64_t HELPER(abs_i64)(int64_t val)
 148 {
 149     HELPER_LOG("%s: val 0x%" PRIx64 "\n", __func__, val);
 150
 151     if (val < 0) {
 152         return -val;
 153     } else {
 154         return val;
 155     }
 156 }
 157
 158 /* negative absolute value 64-bit */
 159 int64_t HELPER(nabs_i64)(int64_t val)
 160 {
 161     if (val < 0) {
 162         return val;
 163     } else {
 164         return -val;
 165     }
 166 }
 167
 168 /* count leading zeros, for find leftmost one */
 169 uint64_t HELPER(clz)(uint64_t v)
 170 {
 171     return clz64(v);
 172 }
 173
 174 uint64_t HELPER(cvd)(int32_t bin)
 175 {
 176     /* positive 0 */
 177     uint64_t dec = 0x0c;
 178     int shift = 4;
 179
 180     if (bin < 0) {
 181         bin = -bin;
 182         dec = 0x0d;
 183     }
 184
 185     for (shift = 4; (shift < 64) && bin; shift += 4) {
 186         int current_number = bin % 10;
 187
 188         dec |= (current_number) << shift;
 189         bin /= 10;
 190     }
 191
 192     return dec;
 193 }
 194
 195 uint64_t HELPER(popcnt)(uint64_t r2)
 196 {
 197     uint64_t ret = 0;
 198     int i;
 199
 200     for (i = 0; i < 64; i += 8) {
 201         uint64_t t = ctpop32((r2 >> i) & 0xff);
 202         ret |= t << i;
 203     }
 204     return ret;
 205 }