mirror of
https://github.com/php/php-src.git
synced 2026-03-26 17:22:15 +01:00
e56ed6e1ab
Re-formats the BCmath extension to have consistent formatting. Mostly, it adds the spaces in calculations to have them more readable. Also: - removes unused headers - removes few variables which are used only once in the code Co-authored-by: George Peter Banyard <girgias@php.net>
120 lines
3.4 KiB
C
120 lines
3.4 KiB
C
/* raise.c: bcmath library file. */
|
|
/*
|
|
Copyright (C) 1991, 1992, 1993, 1994, 1997 Free Software Foundation, Inc.
|
|
Copyright (C) 2000 Philip A. Nelson
|
|
|
|
This library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2 of the License, or (at your option) any later version.
|
|
|
|
This library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details. (LICENSE)
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with this library; if not, write to:
|
|
|
|
The Free Software Foundation, Inc.
|
|
59 Temple Place, Suite 330
|
|
Boston, MA 02111-1307 USA.
|
|
|
|
You may contact the author by:
|
|
e-mail: philnelson@acm.org
|
|
us-mail: Philip A. Nelson
|
|
Computer Science Department, 9062
|
|
Western Washington University
|
|
Bellingham, WA 98226-9062
|
|
|
|
*************************************************************************/
|
|
|
|
#include "bcmath.h"
|
|
#include <assert.h>
|
|
#include <stdbool.h>
|
|
#include <stddef.h>
|
|
|
|
|
|
/* Raise NUM1 to the NUM2 power. The result is placed in RESULT.
|
|
Maximum exponent is LONG_MAX. If a NUM2 is not an integer,
|
|
only the integer part is used. */
|
|
|
|
void bc_raise(bc_num num1, long exponent, bc_num *result, size_t scale)
|
|
{
|
|
bc_num temp, power;
|
|
size_t rscale;
|
|
size_t pwrscale;
|
|
size_t calcscale;
|
|
bool is_neg;
|
|
|
|
/* Special case if exponent is a zero. */
|
|
if (exponent == 0) {
|
|
bc_free_num (result);
|
|
*result = bc_copy_num(BCG(_one_));
|
|
return;
|
|
}
|
|
|
|
/* Other initializations. */
|
|
if (exponent < 0) {
|
|
is_neg = true;
|
|
exponent = -exponent;
|
|
rscale = scale;
|
|
} else {
|
|
is_neg = false;
|
|
rscale = MIN (num1->n_scale * exponent, MAX(scale, num1->n_scale));
|
|
}
|
|
|
|
/* Set initial value of temp. */
|
|
power = bc_copy_num(num1);
|
|
pwrscale = num1->n_scale;
|
|
while ((exponent & 1) == 0) {
|
|
pwrscale = 2 * pwrscale;
|
|
bc_multiply(power, power, &power, pwrscale);
|
|
exponent = exponent >> 1;
|
|
}
|
|
temp = bc_copy_num(power);
|
|
calcscale = pwrscale;
|
|
exponent = exponent >> 1;
|
|
|
|
/* Do the calculation. */
|
|
while (exponent > 0) {
|
|
pwrscale = 2 * pwrscale;
|
|
bc_multiply(power, power, &power, pwrscale);
|
|
if ((exponent & 1) == 1) {
|
|
calcscale = pwrscale + calcscale;
|
|
bc_multiply(temp, power, &temp, calcscale);
|
|
}
|
|
exponent = exponent >> 1;
|
|
}
|
|
|
|
/* Assign the value. */
|
|
if (is_neg) {
|
|
bc_divide(BCG(_one_), temp, result, rscale);
|
|
bc_free_num (&temp);
|
|
} else {
|
|
bc_free_num (result);
|
|
*result = temp;
|
|
if ((*result)->n_scale > rscale) {
|
|
(*result)->n_scale = rscale;
|
|
}
|
|
}
|
|
bc_free_num (&power);
|
|
}
|
|
|
|
/* This is used internally by BCMath */
|
|
void bc_raise_bc_exponent(bc_num base, bc_num expo, bc_num *result, size_t scale)
|
|
{
|
|
/* Exponent must not have fractional part */
|
|
assert(expo->n_scale == 0);
|
|
|
|
long exponent = bc_num2long(expo);
|
|
/* Exponent must be properly convertable to long */
|
|
if (exponent == 0 && (expo->n_len > 1 || expo->n_value[0] != 0)) {
|
|
assert(false && "Exponent is not well formed in internal call");
|
|
//assert(exponent != 0 || (expo->n_len == 0 && expo->n_value[0] == 0));
|
|
}
|
|
//assert(exponent != 0 || (expo->n_len == 0 && expo->n_value[0] == 0));
|
|
bc_raise(base, exponent, result, scale);
|
|
}
|
|
|