Archipelago » qemu

/*

 * Utility compute operations used by translated code.

 *

 * Copyright (c) 2003 Fabrice Bellard

 * Copyright (c) 2007 Aurelien Jarno

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include <stdlib.h>

#include <stdint.h>

#include "qemu/host-utils.h"

/* Long integer helpers */

#ifndef CONFIG_INT128

static inline void mul64(uint64_t *plow, uint64_t *phigh,

                         uint64_t a, uint64_t b)

{

    typedef union {

        uint64_t ll;

        struct {

#ifdef HOST_WORDS_BIGENDIAN

            uint32_t high, low;

#else

            uint32_t low, high;

#endif

        } l;

    } LL;

    LL rl, rm, rn, rh, a0, b0;

    uint64_t c;

    a0.ll = a;

    b0.ll = b;

    rl.ll = (uint64_t)a0.l.low * b0.l.low;

    rm.ll = (uint64_t)a0.l.low * b0.l.high;

    rn.ll = (uint64_t)a0.l.high * b0.l.low;

    rh.ll = (uint64_t)a0.l.high * b0.l.high;

    c = (uint64_t)rl.l.high + rm.l.low + rn.l.low;

    rl.l.high = c;

    c >>= 32;

    c = c + rm.l.high + rn.l.high + rh.l.low;

    rh.l.low = c;

    rh.l.high += (uint32_t)(c >> 32);

    *plow = rl.ll;

    *phigh = rh.ll;

}

/* Unsigned 64x64 -> 128 multiplication */

void mulu64 (uint64_t *plow, uint64_t *phigh, uint64_t a, uint64_t b)

{

    mul64(plow, phigh, a, b);

}

/* Signed 64x64 -> 128 multiplication */

void muls64 (uint64_t *plow, uint64_t *phigh, int64_t a, int64_t b)

{

    uint64_t rh;

    mul64(plow, &rh, a, b);

    /* Adjust for signs.  */

    if (b < 0) {

        rh -= a;

    }

    if (a < 0) {

        rh -= b;

    }

    *phigh = rh;

}

#endif /* !CONFIG_INT128 */