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 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 */
  35int64_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 */
  56uint64_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 */
  77int64_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 */
  88uint64_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
 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