LXR qemu/target/s390x/int

   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 2.1 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 */
  36int64_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        s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
  43    }
  44
  45    ret = q = a / b;
  46    env->retxl = a % b;
  47
  48    /* Catch non-representable quotient.  */
  49    if (ret != q) {
  50        s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
  51    }
  52
  53    return ret;
  54}
  55
  56/* 64/32 -> 32 unsigned division */
  57uint64_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        s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
  64    }
  65
  66    ret = q = a / b;
  67    env->retxl = a % b;
  68
  69    /* Catch non-representable quotient.  */
  70    if (ret != q) {
  71        s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
  72    }
  73
  74    return ret;
  75}
  76
  77/* 64/64 -> 64 signed division */
  78int64_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        s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
  83    }
  84    env->retxl = a % b;
  85    return a / b;
  86}
  87
  88/* 128 -> 64/64 unsigned division */
  89uint64_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        s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, 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            s390_program_interrupt(env, PGM_FIXPT_DIVIDE, ILEN_AUTO, GETPC());
 110        }
 111#else
 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(env_cpu(env), "128 -> 64/64 division not implemented\n");
 115#endif
 116    }
 117    return ret;
 118}
 119
 120uint64_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
 140uint64_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}
 148