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 "qemu/osdep.h"
  22 #include "cpu.h"
  23 #include "exec/exec-all.h"
  24 #include "qemu/host-utils.h"
  25 #include "exec/helper-proto.h"
  26
  27 /* #define DEBUG_HELPER */
  28 #ifdef DEBUG_HELPER
  29 #define HELPER_LOG(x...) qemu_log(x)
  30 #else
  31 #define HELPER_LOG(x...)
  32 #endif
  33
  34 /* 64/32 -> 32 signed division */
  35 int64_t HELPER(divs32)(CPUS390XState *env, int64_t a, int64_t b64)
  36 {
  37     int32_t ret, b = b64;
  38     int64_t q;
  39
  40     if (b == 0) {
  41         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  42     }
  43
  44     ret = q = a / b;
  45     env->retxl = a % b;
  46
  47     /* Catch non-representable quotient.  */
  48     if (ret != q) {
  49         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  50     }
  51
  52     return ret;
  53 }
  54
  55 /* 64/32 -> 32 unsigned division */
  56 uint64_t HELPER(divu32)(CPUS390XState *env, uint64_t a, uint64_t b64)
  57 {
  58     uint32_t ret, b = b64;
  59     uint64_t q;
  60
  61     if (b == 0) {
  62         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  63     }
  64
  65     ret = q = a / b;
  66     env->retxl = a % b;
  67
  68     /* Catch non-representable quotient.  */
  69     if (ret != q) {
  70         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  71     }
  72
  73     return ret;
  74 }
  75
  76 /* 64/64 -> 64 signed division */
  77 int64_t HELPER(divs64)(CPUS390XState *env, int64_t a, int64_t b)
  78 {
  79     /* Catch divide by zero, and non-representable quotient (MIN / -1).  */
  80     if (b == 0 || (b == -1 && a == (1ll << 63))) {
  81         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  82     }
  83     env->retxl = a % b;
  84     return a / b;
  85 }
  86
  87 /* 128 -> 64/64 unsigned division */
  88 uint64_t HELPER(divu64)(CPUS390XState *env, uint64_t ah, uint64_t al,
  89                         uint64_t b)
  90 {
  91     uint64_t ret;
  92     /* Signal divide by zero.  */
  93     if (b == 0) {
  94         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  95     }
  96     if (ah == 0) {
  97         /* 64 -> 64/64 case */
  98         env->retxl = al % b;
  99         ret = al / b;
 100     } else {
 101         /* ??? Move i386 idivq helper to host-utils.  */
 102 #ifdef CONFIG_INT128
 103         __uint128_t a = ((__uint128_t)ah << 64) | al;
 104         __uint128_t q = a / b;
 105         env->retxl = a % b;
 106         ret = q;
 107         if (ret != q) {
 108             runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
 109         }
 110 #else
 111         S390CPU *cpu = s390_env_get_cpu(env);
 112         /* 32-bit hosts would need special wrapper functionality - just abort if
 113            we encounter such a case; it's very unlikely anyways. */
 114         cpu_abort(CPU(cpu), "128 -> 64/64 division not implemented\n");
 115 #endif
 116     }
 117     return ret;
 118 }
 119
 120 uint64_t HELPER(cvd)(int32_t reg)
 121 {
 122     /* positive 0 */
 123     uint64_t dec = 0x0c;
 124     int64_t bin = reg;
 125     int shift;
 126
 127     if (bin < 0) {
 128         bin = -bin;
 129         dec = 0x0d;
 130     }
 131
 132     for (shift = 4; (shift < 64) && bin; shift += 4) {
 133         dec |= (bin % 10) << shift;
 134         bin /= 10;
 135     }
 136
 137     return dec;
 138 }
 139
 140 uint64_t HELPER(popcnt)(uint64_t val)
 141 {
 142     /* Note that we don't fold past bytes. */
 143     val = (val & 0x5555555555555555ULL) + ((val >> 1) & 0x5555555555555555ULL);
 144     val = (val & 0x3333333333333333ULL) + ((val >> 2) & 0x3333333333333333ULL);
 145     val = (val + (val >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
 146     return val;
 147 }