LXR qemu/util/host-utils.c

   1/*
   2 * Utility compute operations used by translated code.
   3 *
   4 * Copyright (c) 2003 Fabrice Bellard
   5 * Copyright (c) 2007 Aurelien Jarno
   6 *
   7 * Permission is hereby granted, free of charge, to any person obtaining a copy
   8 * of this software and associated documentation files (the "Software"), to deal
   9 * in the Software without restriction, including without limitation the rights
  10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11 * copies of the Software, and to permit persons to whom the Software is
  12 * furnished to do so, subject to the following conditions:
  13 *
  14 * The above copyright notice and this permission notice shall be included in
  15 * all copies or substantial portions of the Software.
  16 *
  17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  23 * THE SOFTWARE.
  24 */
  25
  26#include <stdlib.h>
  27#include <stdint.h>
  28#include "qemu/host-utils.h"
  29
  30/* Long integer helpers */
  31#ifndef CONFIG_INT128
  32static inline void mul64(uint64_t *plow, uint64_t *phigh,
  33                         uint64_t a, uint64_t b)
  34{
  35    typedef union {
  36        uint64_t ll;
  37        struct {
  38#ifdef HOST_WORDS_BIGENDIAN
  39            uint32_t high, low;
  40#else
  41            uint32_t low, high;
  42#endif
  43        } l;
  44    } LL;
  45    LL rl, rm, rn, rh, a0, b0;
  46    uint64_t c;
  47
  48    a0.ll = a;
  49    b0.ll = b;
  50
  51    rl.ll = (uint64_t)a0.l.low * b0.l.low;
  52    rm.ll = (uint64_t)a0.l.low * b0.l.high;
  53    rn.ll = (uint64_t)a0.l.high * b0.l.low;
  54    rh.ll = (uint64_t)a0.l.high * b0.l.high;
  55
  56    c = (uint64_t)rl.l.high + rm.l.low + rn.l.low;
  57    rl.l.high = c;
  58    c >>= 32;
  59    c = c + rm.l.high + rn.l.high + rh.l.low;
  60    rh.l.low = c;
  61    rh.l.high += (uint32_t)(c >> 32);
  62
  63    *plow = rl.ll;
  64    *phigh = rh.ll;
  65}
  66
  67/* Unsigned 64x64 -> 128 multiplication */
  68void mulu64 (uint64_t *plow, uint64_t *phigh, uint64_t a, uint64_t b)
  69{
  70    mul64(plow, phigh, a, b);
  71}
  72
  73/* Signed 64x64 -> 128 multiplication */
  74void muls64 (uint64_t *plow, uint64_t *phigh, int64_t a, int64_t b)
  75{
  76    uint64_t rh;
  77
  78    mul64(plow, &rh, a, b);
  79
  80    /* Adjust for signs.  */
  81    if (b < 0) {
  82        rh -= a;
  83    }
  84    if (a < 0) {
  85        rh -= b;
  86    }
  87    *phigh = rh;
  88}
  89#endif /* !CONFIG_INT128 */
  90