xenocara/app/xedit/lisp/mp/mpr.c

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2006-11-25 13:07:29 -07:00
/*
* Copyright (c) 2002 by The XFree86 Project, Inc.
*
* 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 XFREE86 PROJECT 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.
*
* Except as contained in this notice, the name of the XFree86 Project shall
* not be used in advertising or otherwise to promote the sale, use or other
* dealings in this Software without prior written authorization from the
* XFree86 Project.
*
* Author: Paulo César Pereira de Andrade
*/
/* $XFree86$ */
#include "mp.h"
/*
* TODO:
* Implement a fast gcd and divexact for integers, so that this code
* could be changed to do intermediary calculations faster using smaller
* numbers.
*/
/*
* Prototypes
*/
/* do the hard work of mpr_add and mpr_sub */
static void mpr_addsub(mpr *rop, mpr *op1, mpr *op2, int sub);
/* do the hard work of mpr_cmp and mpr_cmpabs */
static int mpr_docmp(mpr *op1, mpr *op2, int sign);
/*
* Implementation
*/
void
mpr_init(mpr *op)
{
op->num.digs = mp_malloc(sizeof(BNS));
op->num.sign = 0;
op->num.size = op->num.alloc = 1;
op->num.digs[0] = 0;
op->den.digs = mp_malloc(sizeof(BNS));
op->den.sign = 0;
op->den.size = op->den.alloc = 1;
op->den.digs[0] = 1;
}
void
mpr_clear(mpr *op)
{
op->num.sign = 0;
op->num.size = op->num.alloc = 0;
mp_free(op->num.digs);
op->den.sign = 0;
op->den.size = op->den.alloc = 0;
mp_free(op->den.digs);
}
void
mpr_set(mpr *rop, mpr *op)
{
if (rop != op) {
mpi_set(mpr_num(rop), mpr_num(op));
mpi_set(mpr_den(rop), mpr_den(op));
}
}
void
mpr_seti(mpr *rop, long num, long den)
{
mpi_seti(mpr_num(rop), num);
mpi_seti(mpr_den(rop), den);
}
void
mpr_setd(mpr *rop, double d)
{
double val, num;
int e, sign;
/* initialize */
if (d < 0) {
sign = 1;
val = -d;
}
else {
sign = 0;
val = d;
}
val = frexp(val, &e);
while (modf(val, &num) != 0.0 && val <= DBL_MAX / 2.0) {
--e;
val *= 2.0;
}
if (e >= 0) {
mpi_setd(mpr_num(rop), d);
mpi_seti(mpr_den(rop), 1);
}
else {
mpi_setd(mpr_num(rop), sign ? -num : num);
mpi_setd(mpr_den(rop), ldexp(1.0, -e));
}
}
void
mpr_setstr(mpr *rop, char *str, int base)
{
char *slash = strchr(str, '/');
mpi_setstr(mpr_num(rop), str, base);
if (slash != NULL)
mpi_setstr(mpr_den(rop), slash + 1, base);
else
mpi_seti(mpr_den(rop), 1);
}
void
mpr_canonicalize(mpr *op)
{
mpi gcd;
memset(&gcd, '\0', sizeof(mpi));
mpi_gcd(&gcd, mpr_num(op), mpr_den(op));
if (mpi_cmpabsi(&gcd, 1)) {
mpi_div(mpr_num(op), mpr_num(op), &gcd);
mpi_div(mpr_den(op), mpr_den(op), &gcd);
}
if (op->den.sign) {
op->num.sign = !op->num.sign;
op->den.sign = 0;
}
mpi_clear(&gcd);
}
void
mpr_add(mpr *rop, mpr *op1, mpr *op2)
{
mpr_addsub(rop, op1, op2, 0);
}
void
mpr_addi(mpr *rop, mpr *op1, long op2)
{
mpi prod;
memset(&prod, '\0', sizeof(mpi));
mpi_muli(&prod, mpr_den(op1), op2);
mpi_add(mpr_num(rop), mpr_num(op1), &prod);
mpi_clear(&prod);
}
void
mpr_sub(mpr *rop, mpr *op1, mpr *op2)
{
mpr_addsub(rop, op1, op2, 1);
}
void
mpr_subi(mpr *rop, mpr *op1, long op2)
{
mpi prod;
memset(&prod, '\0', sizeof(mpi));
mpi_muli(&prod, mpr_den(op1), op2);
mpi_sub(mpr_num(rop), mpr_num(op1), &prod);
mpi_clear(&prod);
}
static void
mpr_addsub(mpr *rop, mpr *op1, mpr *op2, int sub)
{
mpi prod1, prod2;
memset(&prod1, '\0', sizeof(mpi));
memset(&prod2, '\0', sizeof(mpi));
mpi_mul(&prod1, mpr_num(op1), mpr_den(op2));
mpi_mul(&prod2, mpr_num(op2), mpr_den(op1));
if (sub)
mpi_sub(mpr_num(rop), &prod1, &prod2);
else
mpi_add(mpr_num(rop), &prod1, &prod2);
mpi_clear(&prod1);
mpi_clear(&prod2);
mpi_mul(mpr_den(rop), mpr_den(op1), mpr_den(op2));
}
void
mpr_mul(mpr *rop, mpr *op1, mpr *op2)
{
/* check if temporary storage is required */
if (op1 == op2 && rop == op1) {
mpi prod;
memset(&prod, '\0', sizeof(mpi));
mpi_mul(&prod, mpr_num(op1), mpr_num(op2));
mpi_mul(mpr_den(rop), mpr_den(op1), mpr_den(op2));
mpi_set(mpr_num(rop), &prod);
mpi_clear(&prod);
}
else {
mpi_mul(mpr_num(rop), mpr_num(op1), mpr_num(op2));
mpi_mul(mpr_den(rop), mpr_den(op1), mpr_den(op2));
}
}
void
mpr_muli(mpr *rop, mpr *op1, long op2)
{
mpi_muli(mpr_num(rop), mpr_num(op1), op2);
}
void
mpr_div(mpr *rop, mpr *op1, mpr *op2)
{
/* check if temporary storage is required */
if (op1 == op2 && rop == op1) {
mpi prod;
memset(&prod, '\0', sizeof(mpi));
mpi_mul(&prod, mpr_num(op1), mpr_den(op2));
mpi_mul(mpr_den(rop), mpr_num(op2), mpr_den(op1));
mpi_set(mpr_num(rop), &prod);
mpi_clear(&prod);
}
else {
mpi_mul(mpr_num(rop), mpr_num(op1), mpr_den(op2));
mpi_mul(mpr_den(rop), mpr_num(op2), mpr_den(op1));
}
}
void
mpr_divi(mpr *rop, mpr *op1, long op2)
{
mpi_muli(mpr_den(rop), mpr_den(op1), op2);
}
void
mpr_inv(mpr *rop, mpr *op)
{
if (rop == op)
mpi_swap(mpr_num(op), mpr_den(op));
else {
mpi_set(mpr_num(rop), mpr_den(op));
mpi_set(mpr_den(rop), mpr_num(op));
}
}
void
mpr_neg(mpr *rop, mpr *op)
{
mpi_neg(mpr_num(rop), mpr_num(op));
mpi_set(mpr_den(rop), mpr_den(op));
}
void
mpr_abs(mpr *rop, mpr *op)
{
if (mpr_num(op)->sign)
mpi_neg(mpr_num(rop), mpr_num(op));
else
mpi_set(mpr_num(rop), mpr_num(op));
/* op may not be canonicalized */
if (mpr_den(op)->sign)
mpi_neg(mpr_den(rop), mpr_den(op));
else
mpi_set(mpr_den(rop), mpr_den(op));
}
int
mpr_cmp(mpr *op1, mpr *op2)
{
return (mpr_docmp(op1, op2, 1));
}
int
mpr_cmpi(mpr *op1, long op2)
{
int cmp;
mpr rat;
mpr_init(&rat);
mpi_seti(mpr_num(&rat), op2);
cmp = mpr_docmp(op1, &rat, 1);
mpr_clear(&rat);
return (cmp);
}
int
mpr_cmpabs(mpr *op1, mpr *op2)
{
return (mpr_docmp(op1, op2, 0));
}
int
mpr_cmpabsi(mpr *op1, long op2)
{
int cmp;
mpr rat;
mpr_init(&rat);
mpi_seti(mpr_num(&rat), op2);
cmp = mpr_docmp(op1, &rat, 0);
mpr_clear(&rat);
return (cmp);
}
static int
mpr_docmp(mpr *op1, mpr *op2, int sign)
{
int cmp, neg;
mpi prod1, prod2;
neg = 0;
if (sign) {
/* if op1 is negative */
if (mpr_num(op1)->sign ^ mpr_den(op1)->sign) {
/* if op2 is positive */
if (!(mpr_num(op2)->sign ^ mpr_den(op2)->sign))
return (-1);
else
neg = 1;
}
/* if op2 is negative */
else if (mpr_num(op2)->sign ^ mpr_den(op2)->sign)
return (1);
/* else same sign */
}
/* if denominators are equal, compare numerators */
if (mpi_cmpabs(mpr_den(op1), mpr_den(op2)) == 0) {
cmp = mpi_cmpabs(mpr_num(op1), mpr_num(op2));
if (cmp == 0)
return (0);
if (sign && neg)
return (cmp < 0 ? 1 : -1);
return (cmp);
}
memset(&prod1, '\0', sizeof(mpi));
memset(&prod2, '\0', sizeof(mpi));
/* "divide" op1 by op2
* if result is smaller than 1, op1 is smaller than op2 */
mpi_mul(&prod1, mpr_num(op1), mpr_den(op2));
mpi_mul(&prod2, mpr_num(op2), mpr_den(op1));
cmp = mpi_cmpabs(&prod1, &prod2);
mpi_clear(&prod1);
mpi_clear(&prod2);
if (sign && neg)
return (cmp < 0 ? 1 : -1);
return (cmp);
}
void
mpr_swap(mpr *op1, mpr *op2)
{
if (op1 != op2) {
mpr swap;
memcpy(&swap, op1, sizeof(mpr));
memcpy(op1, op2, sizeof(mpr));
memcpy(op2, &swap, sizeof(mpr));
}
}
int
mpr_fiti(mpr *op)
{
return (mpi_fiti(mpr_num(op)) && mpi_fiti(mpr_den(op)));
}
double
mpr_getd(mpr *op)
{
return (mpi_getd(mpr_num(op)) / mpi_getd(mpr_den(op)));
}
char *
mpr_getstr(char *str, mpr *op, int base)
{
int len;
if (str == NULL) {
len = mpi_getsize(mpr_num(op), base) + mpr_num(op)->sign + 1 +
mpi_getsize(mpr_den(op), base) + mpr_den(op)->sign + 1;
str = mp_malloc(len);
}
(void)mpi_getstr(str, mpr_num(op), base);
len = strlen(str);
str[len] = '/';
(void)mpi_getstr(str + len + 1, mpr_den(op), base);
return (str);
}