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 "qemu/host-utils.h"
  24#include "exec/helper-proto.h"
  25
  26/* #define DEBUG_HELPER */
  27#ifdef DEBUG_HELPER
  28#define HELPER_LOG(x...) qemu_log(x)
  29#else
  30#define HELPER_LOG(x...)
  31#endif
  32
  33/* 64/32 -> 32 signed division */
  34int64_t HELPER(divs32)(CPUS390XState *env, int64_t a, int64_t b64)
  35{
  36    int32_t ret, b = b64;
  37    int64_t q;
  38
  39    if (b == 0) {
  40        runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  41    }
  42
  43    ret = q = a / b;
  44    env->retxl = a % b;
  45
  46    /* Catch non-representable quotient.  */
  47    if (ret != q) {
  48        runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  49    }
  50
  51    return ret;
  52}
  53
  54/* 64/32 -> 32 unsigned division */
  55uint64_t HELPER(divu32)(CPUS390XState *env, uint64_t a, uint64_t b64)
  56{
  57    uint32_t ret, b = b64;
  58    uint64_t q;
  59
  60    if (b == 0) {
  61        runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  62    }
  63
  64    ret = q = a / b;
  65    env->retxl = a % b;
  66
  67    /* Catch non-representable quotient.  */
  68    if (ret != q) {
  69        runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  70    }
  71
  72    return ret;
  73}
  74
  75/* 64/64 -> 64 signed division */
  76int64_t HELPER(divs64)(CPUS390XState *env, int64_t a, int64_t b)
  77{
  78    /* Catch divide by zero, and non-representable quotient (MIN / -1).  */
  79    if (b == 0 || (b == -1 && a == (1ll << 63))) {
  80        runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  81    }
  82    env->retxl = a % b;
  83    return a / b;
  84}
  85
  86/* 128 -> 64/64 unsigned division */
  87uint64_t HELPER(divu64)(CPUS390XState *env, uint64_t ah, uint64_t al,
  88                        uint64_t b)
  89{
  90    uint64_t ret;
  91    /* Signal divide by zero.  */
  92    if (b == 0) {
  93        runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
  94    }
  95    if (ah == 0) {
  96        /* 64 -> 64/64 case */
  97        env->retxl = al % b;
  98        ret = al / b;
  99    } else {
 100        /* ??? Move i386 idivq helper to host-utils.  */
 101#ifdef CONFIG_INT128
 102        __uint128_t a = ((__uint128_t)ah << 64) | al;
 103        __uint128_t q = a / b;
 104        env->retxl = a % b;
 105        ret = q;
 106        if (ret != q) {
 107            runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());
 108        }
 109#else
 110        S390CPU *cpu = s390_env_get_cpu(env);
 111        /* 32-bit hosts would need special wrapper functionality - just abort if
 112           we encounter such a case; it's very unlikely anyways. */
 113        cpu_abort(CPU(cpu), "128 -> 64/64 division not implemented\n");
 114#endif
 115    }
 116    return ret;
 117}
 118
 119/* count leading zeros, for find leftmost one */
 120uint64_t HELPER(clz)(uint64_t v)
 121{
 122    return clz64(v);
 123}
 124
 125uint64_t HELPER(cvd)(int32_t reg)
 126{
 127    /* positive 0 */
 128    uint64_t dec = 0x0c;
 129    int64_t bin = reg;
 130    int shift;
 131
 132    if (bin < 0) {
 133        bin = -bin;
 134        dec = 0x0d;
 135    }
 136
 137    for (shift = 4; (shift < 64) && bin; shift += 4) {
 138        dec |= (bin % 10) << shift;
 139        bin /= 10;
 140    }
 141
 142    return dec;
 143}
 144
 145uint64_t HELPER(popcnt)(uint64_t r2)
 146{
 147    uint64_t ret = 0;
 148    int i;
 149
 150    for (i = 0; i < 64; i += 8) {
 151        uint64_t t = ctpop32((r2 >> i) & 0xff);
 152        ret |= t << i;
 153    }
 154    return ret;
 155}
 156