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 "exec/helper-proto.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         S390CPU *cpu = s390_env_get_cpu(env);
 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(CPU(cpu), "128 -> 64/64 division not implemented\n");
 113 #endif
 114     }
 115     return ret;
 116 }
 117
 118 /* count leading zeros, for find leftmost one */
 119 uint64_t HELPER(clz)(uint64_t v)
 120 {
 121     return clz64(v);
 122 }
 123
 124 uint64_t HELPER(cvd)(int32_t reg)
 125 {
 126     /* positive 0 */
 127     uint64_t dec = 0x0c;
 128     int64_t bin = reg;
 129     int shift;
 130
 131     if (bin < 0) {
 132         bin = -bin;
 133         dec = 0x0d;
 134     }
 135
 136     for (shift = 4; (shift < 64) && bin; shift += 4) {
 137         dec |= (bin % 10) << shift;
 138         bin /= 10;
 139     }
 140
 141     return dec;
 142 }
 143
 144 uint64_t HELPER(popcnt)(uint64_t r2)
 145 {
 146     uint64_t ret = 0;
 147     int i;
 148
 149     for (i = 0; i < 64; i += 8) {
 150         uint64_t t = ctpop32((r2 >> i) & 0xff);
 151         ret |= t << i;
 152     }
 153     return ret;
 154 }