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810 cejka 1 
/*
2071 jermar 2 
 * Copyright (c) 2006 Josef Cejka
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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1888 jermar 29 
/** @addtogroup genarch
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 * @{
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 */
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/** @file
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 */
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#include <genarch/softint/division.h>
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#define ABSVAL(x) ((x) > 0 ? (x) : -(x))
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#define SGN(x) ((x) >= 0 ? 1 : 0)
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static unsigned int divandmod32(unsigned int a, unsigned int b,
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    unsigned int *remainder)
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{
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    unsigned int result;
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    int steps = sizeof(unsigned int) * 8;
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    *remainder = 0;
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    result = 0;
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    if (b == 0) {
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        /* FIXME: division by zero */
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        return 0;
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    }
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    if (a < b) {
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        *remainder = a;
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        return 0;
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    }
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    for (; steps > 0; steps--) {
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        /* shift one bit to remainder */
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        *remainder = ((*remainder) << 1) | (( a >> 31) & 0x1);
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        result <<= 1;
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        if (*remainder >= b) {
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            *remainder -= b;
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            result |= 0x1;
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        }
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        a <<= 1;
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    }
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    return result;
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}
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2505 jermar 75 
static unsigned long long divandmod64(unsigned long long a,
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    unsigned long long b, unsigned long long *remainder)
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{
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    unsigned long long result;
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    int steps = sizeof(unsigned long long) * 8;
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    *remainder = 0;
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    result = 0;
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    if (b == 0) {
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        /* FIXME: division by zero */
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        return 0;
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    }
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2505 jermar 89 
    if (a < b) {
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        *remainder = a;
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        return 0;
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    }
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2505 jermar 94 
    for (; steps > 0; steps--) {
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        /* shift one bit to remainder */
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        *remainder = ((*remainder) << 1) | ((a >> 63) & 0x1);
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        result <<= 1;
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        if (*remainder >= b) {
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            *remainder -= b;
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            result |= 0x1;
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        }
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        a <<= 1;
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    }
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    return result;
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}
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/* 32bit integer division */
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int __divsi3(int a, int b)
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{
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    unsigned int rem;
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    int result;
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2505 jermar 115 
    result = (int) divandmod32(ABSVAL(a), ABSVAL(b), &rem);
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    if (SGN(a) == SGN(b))
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        return result;
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    return -result;
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}
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/* 64bit integer division */
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long long __divdi3(long long a, long long b)
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{
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    unsigned long long rem;
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    long long result;
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2505 jermar 128 
    result = (long long) divandmod64(ABSVAL(a), ABSVAL(b), &rem);
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    if (SGN(a) == SGN(b))
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        return result;
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    return -result;
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}
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/* 32bit unsigned integer division */
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unsigned int __udivsi3(unsigned int a, unsigned int b)
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{
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    unsigned int rem;
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    return divandmod32(a, b, &rem);
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}
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/* 64bit unsigned integer division */
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unsigned long long __udivdi3(unsigned long long a, unsigned long long b)
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{
1196 cejka 145 
    unsigned long long  rem;
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    return divandmod64(a, b, &rem);
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}
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/* 32bit remainder of the signed division */
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int __modsi3(int a, int b)
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{
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    unsigned int rem;
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    divandmod32(a, b, &rem);
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    /* if divident is negative, remainder must be too */
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    if (!(SGN(a))) {
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        return -((int) rem);
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    }
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2505 jermar 160 
    return (int) rem;
810 cejka 161 
}
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/* 64bit remainder of the signed division */
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long long __moddi3(long long a,long  long b)
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{
1196 cejka 166 
    unsigned long long rem;
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    divandmod64(a, b, &rem);
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    /* if divident is negative, remainder must be too */
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    if (!(SGN(a))) {
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        return -((long long) rem);
810 cejka 172 
    }
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2505 jermar 174 
    return (long long) rem;
810 cejka 175 
}
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/* 32bit remainder of the unsigned division */
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unsigned int __umodsi3(unsigned int a, unsigned int b)
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{
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    unsigned int rem;
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    divandmod32(a, b, &rem);
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    return rem;
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}
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/* 64bit remainder of the unsigned division */
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unsigned long long __umoddi3(unsigned long long a, unsigned long long b)
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{
1196 cejka 188 
    unsigned long long rem;
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    divandmod64(a, b, &rem);
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    return rem;
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}
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2505 jermar 193 
unsigned long long __udivmoddi3(unsigned long long a, unsigned long long b,
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    unsigned long long *c)
810 cejka 195 
{
196 
    return divandmod64(a, b, c);
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}
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1888 jermar 199 
/** @}
1702 cejka 200 
 */