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 "internal.h"
  24 #include "exec/exec-all.h"
  25 #include "qemu/host-utils.h"
  26 #include "exec/helper-proto.h"
  27
  28 /* #define DEBUG_HELPER */
  29 #ifdef DEBUG_HELPER
  30 #define HELPER_LOG(x...) qemu_log(x)
  31 #else
  32 #define HELPER_LOG(x...)
  33 #endif
  34
  35 /* 64/32 -> 32 signed division */
  36 int64_t HELPER(divs32)(CPUS390XState *env, int64_t a, int64_t b64)
  37 {
  38     int32_t ret, b = b64;
  39     int64_t q;
  40
  41     if (b == 0) {
  42         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  43     }
  44
  45     ret = q = a / b;
  46     env->retxl = a % b;
  47
  48     /* Catch non-representable quotient.  */
  49     if (ret != q) {
  50         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  51     }
  52
  53     return ret;
  54 }
  55
  56 /* 64/32 -> 32 unsigned division */
  57 uint64_t HELPER(divu32)(CPUS390XState *env, uint64_t a, uint64_t b64)
  58 {
  59     uint32_t ret, b = b64;
  60     uint64_t q;
  61
  62     if (b == 0) {
  63         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  64     }
  65
  66     ret = q = a / b;
  67     env->retxl = a % b;
  68
  69     /* Catch non-representable quotient.  */
  70     if (ret != q) {
  71         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  72     }
  73
  74     return ret;
  75 }
  76
  77 /* 64/64 -> 64 signed division */
  78 int64_t HELPER(divs64)(CPUS390XState *env, int64_t a, int64_t b)
  79 {
  80     /* Catch divide by zero, and non-representable quotient (MIN / -1).  */
  81     if (b == 0 || (b == -1 && a == (1ll << 63))) {
  82         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  83     }
  84     env->retxl = a % b;
  85     return a / b;
  86 }
  87
  88 /* 128 -> 64/64 unsigned division */
  89 uint64_t HELPER(divu64)(CPUS390XState *env, uint64_t ah, uint64_t al,
  90                         uint64_t b)
  91 {
  92     uint64_t ret;
  93     /* Signal divide by zero.  */
  94     if (b == 0) {
  95         runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  96     }
  97     if (ah == 0) {
  98         /* 64 -> 64/64 case */
  99         env->retxl = al % b;
 100         ret = al / b;
 101     } else {
 102         /* ??? Move i386 idivq helper to host-utils.  */
 103 #ifdef CONFIG_INT128
 104         __uint128_t a = ((__uint128_t)ah << 64) | al;
 105         __uint128_t q = a / b;
 106         env->retxl = a % b;
 107         ret = q;
 108         if (ret != q) {
 109             runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
 110         }
 111 #else
 112         S390CPU *cpu = s390_env_get_cpu(env);
 113         /* 32-bit hosts would need special wrapper functionality - just abort if
 114            we encounter such a case; it's very unlikely anyways. */
 115         cpu_abort(CPU(cpu), "128 -> 64/64 division not implemented\n");
 116 #endif
 117     }
 118     return ret;
 119 }
 120
 121 uint64_t HELPER(cvd)(int32_t reg)
 122 {
 123     /* positive 0 */
 124     uint64_t dec = 0x0c;
 125     int64_t bin = reg;
 126     int shift;
 127
 128     if (bin < 0) {
 129         bin = -bin;
 130         dec = 0x0d;
 131     }
 132
 133     for (shift = 4; (shift < 64) && bin; shift += 4) {
 134         dec |= (bin % 10) << shift;
 135         bin /= 10;
 136     }
 137
 138     return dec;
 139 }
 140
 141 uint64_t HELPER(popcnt)(uint64_t val)
 142 {
 143     /* Note that we don't fold past bytes. */
 144     val = (val & 0x5555555555555555ULL) + ((val >> 1) & 0x5555555555555555ULL);
 145     val = (val & 0x3333333333333333ULL) + ((val >> 2) & 0x3333333333333333ULL);
 146     val = (val + (val >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
 147     return val;
 148 }