LXR qemu/target/s390x/tcg/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 "s390x-internal.h"
  24#include "tcg_s390x.h"
  25#include "exec/exec-all.h"
  26#include "qemu/host-utils.h"
  27#include "exec/helper-proto.h"
  28
  29/* #define DEBUG_HELPER */
  30#ifdef DEBUG_HELPER
  31#define HELPER_LOG(x...) qemu_log(x)
  32#else
  33#define HELPER_LOG(x...)
  34#endif
  35
  36/* 64/32 -> 32 signed division */
  37int64_t HELPER(divs32)(CPUS390XState *env, int64_t a, int64_t b64)
  38{
  39    int32_t ret, b = b64;
  40    int64_t q;
  41
  42    if (b == 0) {
  43        tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
  44    }
  45
  46    ret = q = a / b;
  47    env->retxl = a % b;
  48
  49    /* Catch non-representable quotient.  */
  50    if (ret != q) {
  51        tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
  52    }
  53
  54    return ret;
  55}
  56
  57/* 64/32 -> 32 unsigned division */
  58uint64_t HELPER(divu32)(CPUS390XState *env, uint64_t a, uint64_t b64)
  59{
  60    uint32_t ret, b = b64;
  61    uint64_t q;
  62
  63    if (b == 0) {
  64        tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
  65    }
  66
  67    ret = q = a / b;
  68    env->retxl = a % b;
  69
  70    /* Catch non-representable quotient.  */
  71    if (ret != q) {
  72        tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
  73    }
  74
  75    return ret;
  76}
  77
  78/* 64/64 -> 64 signed division */
  79int64_t HELPER(divs64)(CPUS390XState *env, int64_t a, int64_t b)
  80{
  81    /* Catch divide by zero, and non-representable quotient (MIN / -1).  */
  82    if (b == 0 || (b == -1 && a == (1ll << 63))) {
  83        tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
  84    }
  85    env->retxl = a % b;
  86    return a / b;
  87}
  88
  89/* 128 -> 64/64 unsigned division */
  90uint64_t HELPER(divu64)(CPUS390XState *env, uint64_t ah, uint64_t al,
  91                        uint64_t b)
  92{
  93    uint64_t ret;
  94    /* Signal divide by zero.  */
  95    if (b == 0) {
  96        tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
  97    }
  98    if (ah == 0) {
  99        /* 64 -> 64/64 case */
 100        env->retxl = al % b;
 101        ret = al / b;
 102    } else {
 103        /* ??? Move i386 idivq helper to host-utils.  */
 104#ifdef CONFIG_INT128
 105        __uint128_t a = ((__uint128_t)ah << 64) | al;
 106        __uint128_t q = a / b;
 107        env->retxl = a % b;
 108        ret = q;
 109        if (ret != q) {
 110            tcg_s390_program_interrupt(env, PGM_FIXPT_DIVIDE, GETPC());
 111        }
 112#else
 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(env_cpu(env), "128 -> 64/64 division not implemented\n");
 116#endif
 117    }
 118    return ret;
 119}
 120
 121uint64_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
 141uint64_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}
 149