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 void HELPER(mlg)(CPUS390XState *env, uint32_t r1, uint64_t v2)
  34 {
  35 #if HOST_LONG_BITS == 64 && defined(__GNUC__)
  36     /* assuming 64-bit hosts have __uint128_t */
  37     __uint128_t res = (__uint128_t)env->regs[r1 + 1];
  38
  39     res *= (__uint128_t)v2;
  40     env->regs[r1] = (uint64_t)(res >> 64);
  41     env->regs[r1 + 1] = (uint64_t)res;
  42 #else
  43     mulu64(&env->regs[r1 + 1], &env->regs[r1], env->regs[r1 + 1], v2);
  44 #endif
  45 }
  46
  47 /* 128 -> 64/64 unsigned division */
  48 void HELPER(dlg)(CPUS390XState *env, uint32_t r1, uint64_t v2)
  49 {
  50     uint64_t divisor = v2;
  51
  52     if (!env->regs[r1]) {
  53         /* 64 -> 64/64 case */
  54         env->regs[r1] = env->regs[r1 + 1] % divisor;
  55         env->regs[r1 + 1] = env->regs[r1 + 1] / divisor;
  56         return;
  57     } else {
  58 #if HOST_LONG_BITS == 64 && defined(__GNUC__)
  59         /* assuming 64-bit hosts have __uint128_t */
  60         __uint128_t dividend = (((__uint128_t)env->regs[r1]) << 64) |
  61             (env->regs[r1 + 1]);
  62         __uint128_t quotient = dividend / divisor;
  63         __uint128_t remainder = dividend % divisor;
  64
  65         env->regs[r1 + 1] = quotient;
  66         env->regs[r1] = remainder;
  67 #else
  68         /* 32-bit hosts would need special wrapper functionality - just abort if
  69            we encounter such a case; it's very unlikely anyways. */
  70         cpu_abort(env, "128 -> 64/64 division not implemented\n");
  71 #endif
  72     }
  73 }
  74
  75 /* absolute value 32-bit */
  76 uint32_t HELPER(abs_i32)(int32_t val)
  77 {
  78     if (val < 0) {
  79         return -val;
  80     } else {
  81         return val;
  82     }
  83 }
  84
  85 /* negative absolute value 32-bit */
  86 int32_t HELPER(nabs_i32)(int32_t val)
  87 {
  88     if (val < 0) {
  89         return val;
  90     } else {
  91         return -val;
  92     }
  93 }
  94
  95 /* absolute value 64-bit */
  96 uint64_t HELPER(abs_i64)(int64_t val)
  97 {
  98     HELPER_LOG("%s: val 0x%" PRIx64 "\n", __func__, val);
  99
 100     if (val < 0) {
 101         return -val;
 102     } else {
 103         return val;
 104     }
 105 }
 106
 107 /* negative absolute value 64-bit */
 108 int64_t HELPER(nabs_i64)(int64_t val)
 109 {
 110     if (val < 0) {
 111         return val;
 112     } else {
 113         return -val;
 114     }
 115 }
 116
 117 /* add with carry 32-bit unsigned */
 118 uint32_t HELPER(addc_u32)(uint32_t cc, uint32_t v1, uint32_t v2)
 119 {
 120     uint32_t res;
 121
 122     res = v1 + v2;
 123     if (cc & 2) {
 124         res++;
 125     }
 126
 127     return res;
 128 }
 129
 130 /* subtract unsigned v2 from v1 with borrow */
 131 uint32_t HELPER(slb)(CPUS390XState *env, uint32_t cc, uint32_t r1, uint32_t v2)
 132 {
 133     uint32_t v1 = env->regs[r1];
 134     uint32_t res = v1 + (~v2) + (cc >> 1);
 135
 136     env->regs[r1] = (env->regs[r1] & 0xffffffff00000000ULL) | res;
 137     if (cc & 2) {
 138         /* borrow */
 139         return v1 ? 1 : 0;
 140     } else {
 141         return v1 ? 3 : 2;
 142     }
 143 }
 144
 145 /* subtract unsigned v2 from v1 with borrow */
 146 uint32_t HELPER(slbg)(CPUS390XState *env, uint32_t cc, uint32_t r1,
 147                       uint64_t v1, uint64_t v2)
 148 {
 149     uint64_t res = v1 + (~v2) + (cc >> 1);
 150
 151     env->regs[r1] = res;
 152     if (cc & 2) {
 153         /* borrow */
 154         return v1 ? 1 : 0;
 155     } else {
 156         return v1 ? 3 : 2;
 157     }
 158 }
 159
 160 /* find leftmost one */
 161 uint32_t HELPER(flogr)(CPUS390XState *env, uint32_t r1, uint64_t v2)
 162 {
 163     uint64_t res = 0;
 164     uint64_t ov2 = v2;
 165
 166     while (!(v2 & 0x8000000000000000ULL) && v2) {
 167         v2 <<= 1;
 168         res++;
 169     }
 170
 171     if (!v2) {
 172         env->regs[r1] = 64;
 173         env->regs[r1 + 1] = 0;
 174         return 0;
 175     } else {
 176         env->regs[r1] = res;
 177         env->regs[r1 + 1] = ov2 & ~(0x8000000000000000ULL >> res);
 178         return 2;
 179     }
 180 }
 181
 182 uint64_t HELPER(cvd)(int32_t bin)
 183 {
 184     /* positive 0 */
 185     uint64_t dec = 0x0c;
 186     int shift = 4;
 187
 188     if (bin < 0) {
 189         bin = -bin;
 190         dec = 0x0d;
 191     }
 192
 193     for (shift = 4; (shift < 64) && bin; shift += 4) {
 194         int current_number = bin % 10;
 195
 196         dec |= (current_number) << shift;
 197         bin /= 10;
 198     }
 199
 200     return dec;
 201 }