floor_or_ceil.c

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/*
   +----------------------------------------------------------------------+
   | Copyright (c) The PHP Group                                          |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | https://www.php.net/license/3_01.txt                                 |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Saki Takamachi <saki@php.net>                               |
   +----------------------------------------------------------------------+
*/
 
#include "bcmath.h"
#include "private.h"
#include <stddef.h>
 
bc_num bc_floor_or_ceil(bc_num num, bool is_floor)
{
    /*  Initialize result */
    bc_num result = bc_new_num(num->n_len, 0);
    result->n_sign = num->n_sign;
 
    /* copy integer part */
    memcpy(result->n_value, num->n_value, num->n_len);
 
    /* If the number is positive and we are flooring, then nothing else needs to be done.
     * Similarly, if the number is negative and we are ceiling, then nothing else needs to be done. */
    if (num->n_scale == 0 || result->n_sign == (is_floor ? PLUS : MINUS)) {
        goto check_zero;
    }
 
    /* check fractional part. */
    size_t count = num->n_scale;
    const char *nptr = num->n_value + num->n_len;
    while ((count > 0) && (*nptr == 0)) {
        count--;
        nptr++;
    }
 
    /* If all digits past the decimal point are 0 */
    if (count == 0) {
        goto check_zero;
    }
 
    /* Increment the absolute value of the result by 1 and add sign information */
    bc_num tmp = _bc_do_add(result, BCG(_one_));
    tmp->n_sign = result->n_sign;
    bc_free_num(&result);
    result = tmp;
 
check_zero:
    if (bc_is_zero(result)) {
        result->n_sign = PLUS;
    }
 
    return result;
}