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calc/qmath.c
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1504 lines
36 KiB
C

/*
* qmath - extended precision rational arithmetic primitive routines
*
* Copyright (C) 1999-2007,2014,2021-2023 David I. Bell, Landon Curt Noll and Ernest Bowen
*
* Primary author: David I. Bell
*
* Calc is open software; you can redistribute it and/or modify it under
* the terms of the version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* Calc 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.
*
* A copy of version 2.1 of the GNU Lesser General Public License is
* distributed with calc under the filename COPYING-LGPL. You should have
* received a copy with calc; if not, write to Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Under source code control: 1990/02/15 01:48:21
* File existed as early as: before 1990
*
* Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/
*/
#include <stdio.h>
#include "qmath.h"
#include "config.h"
#include "errtbl.h"
#include "banned.h" /* include after system header <> includes */
NUMBER _qzero_ = { { _zeroval_, 1, 0 }, { _oneval_, 1, 0 }, 1, NULL };
NUMBER _qone_ = { { _oneval_, 1, 0 }, { _oneval_, 1, 0 }, 1, NULL };
NUMBER _qtwo_ = { { _twoval_, 1, 0 }, { _oneval_, 1, 0 }, 1, NULL };
NUMBER _qten_ = { { _tenval_, 1, 0 }, { _oneval_, 1, 0 }, 1, NULL };
NUMBER _qnegone_ = { { _oneval_, 1, 1 }, { _oneval_, 1, 0 }, 1, NULL };
NUMBER _qonehalf_ = { { _oneval_, 1, 0 }, { _twoval_, 1, 0 }, 1, NULL };
NUMBER _qneghalf_ = { { _oneval_, 1, 1 }, { _twoval_, 1, 0 }, 1, NULL };
NUMBER _qonesqbase_ = { { _oneval_, 1, 0 }, { _sqbaseval_, 2, 0 }, 1, NULL };
NUMBER * initnumbs[] = {&_qzero_, &_qone_, &_qtwo_,
&_qten_, &_qnegone_, &_qonehalf_, &_qneghalf_,
&_qonesqbase_,
NULL /* must be last */
};
/*
* Create another copy of a number.
* q2 = qcopy(q1);
*/
NUMBER *
qcopy(NUMBER *q)
{
register NUMBER *r;
r = qalloc();
r->num.sign = q->num.sign;
if (!zisunit(q->num)) {
r->num.len = q->num.len;
r->num.v = alloc(r->num.len);
zcopyval(q->num, r->num);
}
if (!zisunit(q->den)) {
r->den.len = q->den.len;
r->den.v = alloc(r->den.len);
zcopyval(q->den, r->den);
}
return r;
}
/*
* Convert a number to a normal integer.
* i = qtoi(q);
*/
long
qtoi(NUMBER *q)
{
long i;
ZVALUE res;
if (qisint(q))
return ztoi(q->num);
zquo(q->num, q->den, &res, 0);
i = ztoi(res);
zfree(res);
return i;
}
/*
* Convert a normal integer into a number.
* q = itoq(i);
*/
NUMBER *
itoq(long i)
{
register NUMBER *q;
if ((i >= -1) && (i <= 10)) {
switch ((int) i) {
case 0: q = &_qzero_; break;
case 1: q = &_qone_; break;
case 2: q = &_qtwo_; break;
case 10: q = &_qten_; break;
case -1: q = &_qnegone_; break;
default: q = NULL;
}
if (q)
return qlink(q);
}
q = qalloc();
itoz(i, &q->num);
return q;
}
/*
* Convert a number to a normal unsigned integer.
* u = qtou(q);
*/
FULL
qtou(NUMBER *q)
{
FULL i;
ZVALUE res;
if (qisint(q))
return ztou(q->num);
zquo(q->num, q->den, &res, 0);
i = ztou(res);
zfree(res);
return i;
}
/*
* Convert a number to a normal signed integer.
* s = qtos(q);
*/
SFULL
qtos(NUMBER *q)
{
SFULL i;
ZVALUE res;
if (qisint(q))
return ztos(q->num);
zquo(q->num, q->den, &res, 0);
i = ztos(res);
zfree(res);
return i;
}
/*
* Convert a normal unsigned integer into a number.
* q = utoq(i);
*/
NUMBER *
utoq(FULL i)
{
register NUMBER *q;
if (i <= 10) {
switch ((int) i) {
case 0: q = &_qzero_; break;
case 1: q = &_qone_; break;
case 2: q = &_qtwo_; break;
case 10: q = &_qten_; break;
default: q = NULL;
}
if (q)
return qlink(q);
}
q = qalloc();
utoz(i, &q->num);
return q;
}
/*
* Convert a normal signed integer into a number.
* q = stoq(s);
*/
NUMBER *
stoq(SFULL i)
{
register NUMBER *q;
if (i <= 10) {
switch ((int) i) {
case 0: q = &_qzero_; break;
case 1: q = &_qone_; break;
case 2: q = &_qtwo_; break;
case 10: q = &_qten_; break;
default: q = NULL;
}
if (q)
return qlink(q);
}
q = qalloc();
stoz(i, &q->num);
return q;
}
/*
* Create a number from the given FULL numerator and denominator.
* q = uutoq(inum, iden);
*/
NUMBER *
uutoq(FULL inum, FULL iden)
{
register NUMBER *q;
FULL d;
bool sign;
if (iden == 0) {
math_error("Division by zero");
not_reached();
}
if (inum == 0)
return qlink(&_qzero_);
sign = 0;
d = uugcd(inum, iden);
inum /= d;
iden /= d;
if (iden == 1)
return utoq(inum);
q = qalloc();
if (inum != 1)
utoz(inum, &q->num);
utoz(iden, &q->den);
q->num.sign = sign;
return q;
}
/*
* Create a number from the given integral numerator and denominator.
* q = iitoq(inum, iden);
*/
NUMBER *
iitoq(long inum, long iden)
{
register NUMBER *q;
long d;
bool sign;
if (iden == 0) {
math_error("Division by zero");
not_reached();
}
if (inum == 0)
return qlink(&_qzero_);
sign = 0;
if (inum < 0) {
sign = 1;
inum = -inum;
}
if (iden < 0) {
sign = 1 - sign;
iden = -iden;
}
d = iigcd(inum, iden);
inum /= d;
iden /= d;
if (iden == 1)
return itoq(sign ? -inum : inum);
q = qalloc();
if (inum != 1)
itoz(inum, &q->num);
itoz(iden, &q->den);
q->num.sign = sign;
return q;
}
/*
* Add two numbers to each other.
* q3 = qqadd(q1, q2);
*/
NUMBER *
qqadd(NUMBER *q1, NUMBER *q2)
{
NUMBER *r;
ZVALUE t1, t2, temp, d1, d2, vpd1, upd1;
if (qiszero(q1))
return qlink(q2);
if (qiszero(q2))
return qlink(q1);
r = qalloc();
/*
* If either number is an integer, then the result is easy.
*/
if (qisint(q1) && qisint(q2)) {
zadd(q1->num, q2->num, &r->num);
return r;
}
if (qisint(q2)) {
zmul(q1->den, q2->num, &temp);
zadd(q1->num, temp, &r->num);
zfree(temp);
zcopy(q1->den, &r->den);
return r;
}
if (qisint(q1)) {
zmul(q2->den, q1->num, &temp);
zadd(q2->num, temp, &r->num);
zfree(temp);
zcopy(q2->den, &r->den);
return r;
}
/*
* Both arguments are true fractions, so we need more work.
* If the denominators are relatively prime, then the answer is the
* straightforward cross product result with no need for reduction.
*/
zgcd(q1->den, q2->den, &d1);
if (zisunit(d1)) {
zfree(d1);
zmul(q1->num, q2->den, &t1);
zmul(q1->den, q2->num, &t2);
zadd(t1, t2, &r->num);
zfree(t1);
zfree(t2);
zmul(q1->den, q2->den, &r->den);
return r;
}
/*
* The calculation is now more complicated.
* See Knuth Vol 2 for details.
*/
zquo(q2->den, d1, &vpd1, 0);
zquo(q1->den, d1, &upd1, 0);
zmul(q1->num, vpd1, &t1);
zmul(q2->num, upd1, &t2);
zadd(t1, t2, &temp);
zfree(t1);
zfree(t2);
zfree(vpd1);
zgcd(temp, d1, &d2);
zfree(d1);
if (zisunit(d2)) {
zfree(d2);
r->num = temp;
zmul(upd1, q2->den, &r->den);
zfree(upd1);
return r;
}
zquo(temp, d2, &r->num, 0);
zfree(temp);
zquo(q2->den, d2, &temp, 0);
zfree(d2);
zmul(temp, upd1, &r->den);
zfree(temp);
zfree(upd1);
return r;
}
/*
* Subtract one number from another.
* q3 = qsub(q1, q2);
*/
NUMBER *
qsub(NUMBER *q1, NUMBER *q2)
{
NUMBER *r;
if (q1 == q2)
return qlink(&_qzero_);
if (qiszero(q2))
return qlink(q1);
if (qisint(q1) && qisint(q2)) {
r = qalloc();
zsub(q1->num, q2->num, &r->num);
return r;
}
q2 = qneg(q2);
if (qiszero(q1))
return q2;
r = qqadd(q1, q2);
qfree(q2);
return r;
}
/*
* Increment a number by one.
*/
NUMBER *
qinc(NUMBER *q)
{
NUMBER *r;
r = qalloc();
if (qisint(q)) {
zadd(q->num, _one_, &r->num);
return r;
}
zadd(q->num, q->den, &r->num);
zcopy(q->den, &r->den);
return r;
}
/*
* Decrement a number by one.
*/
NUMBER *
qdec(NUMBER *q)
{
NUMBER *r;
r = qalloc();
if (qisint(q)) {
zsub(q->num, _one_, &r->num);
return r;
}
zsub(q->num, q->den, &r->num);
zcopy(q->den, &r->den);
return r;
}
/*
* Add a normal small integer value to an arbitrary number.
*/
NUMBER *
qaddi(NUMBER *q1, long n)
{
NUMBER addnum; /* temporary number */
HALF addval[2]; /* value of small number */
bool neg; /* true if number is neg */
#if LONG_BITS > BASEB
FULL nf;
#endif
if (n == 0)
return qlink(q1);
if (n == 1)
return qinc(q1);
if (n == -1)
return qdec(q1);
if (qiszero(q1))
return itoq(n);
addnum.num.sign = 0;
addnum.num.v = addval;
addnum.den = _one_;
neg = (n < 0);
if (neg)
n = -n;
addval[0] = (HALF) n;
#if LONG_BITS > BASEB
nf = (((FULL) n) >> BASEB);
if (nf) {
addval[1] = (HALF) nf;
addnum.num.len = 2;
}
#else
addnum.num.len = 1;
#endif
if (neg)
return qsub(q1, &addnum);
else
return qqadd(q1, &addnum);
}
/*
* Multiply two numbers.
* q3 = qmul(q1, q2);
*/
NUMBER *
qmul(NUMBER *q1, NUMBER *q2)
{
NUMBER *r; /* returned value */
ZVALUE n1, n2, d1, d2; /* numerators and denominators */
ZVALUE tmp;
if (qiszero(q1) || qiszero(q2))
return qlink(&_qzero_);
if (qisone(q1))
return qlink(q2);
if (qisone(q2))
return qlink(q1);
if (qisint(q1) && qisint(q2)) { /* easy results if integers */
r = qalloc();
zmul(q1->num, q2->num, &r->num);
return r;
}
n1 = q1->num;
n2 = q2->num;
d1 = q1->den;
d2 = q2->den;
if (ziszero(d1) || ziszero(d2)) {
math_error("Division by zero");
not_reached();
}
if (ziszero(n1) || ziszero(n2))
return qlink(&_qzero_);
if (!zisunit(n1) && !zisunit(d2)) { /* possibly reduce */
zgcd(n1, d2, &tmp);
if (!zisunit(tmp)) {
zequo(q1->num, tmp, &n1);
zequo(q2->den, tmp, &d2);
}
zfree(tmp);
}
if (!zisunit(n2) && !zisunit(d1)) { /* again possibly reduce */
zgcd(n2, d1, &tmp);
if (!zisunit(tmp)) {
zequo(q2->num, tmp, &n2);
zequo(q1->den, tmp, &d1);
}
zfree(tmp);
}
r = qalloc();
zmul(n1, n2, &r->num);
zmul(d1, d2, &r->den);
if (q1->num.v != n1.v)
zfree(n1);
if (q1->den.v != d1.v)
zfree(d1);
if (q2->num.v != n2.v)
zfree(n2);
if (q2->den.v != d2.v)
zfree(d2);
return r;
}
/*
* Multiply a number by a small integer.
* q2 = qmuli(q1, n);
*/
NUMBER *
qmuli(NUMBER *q, long n)
{
NUMBER *r;
long d; /* gcd of multiplier and denominator */
int sign;
if ((n == 0) || qiszero(q))
return qlink(&_qzero_);
if (n == 1)
return qlink(q);
r = qalloc();
if (qisint(q)) {
zmuli(q->num, n, &r->num);
return r;
}
sign = 1;
if (n < 0) {
n = -n;
sign = -1;
}
d = zmodi(q->den, n);
d = iigcd(d, n);
zmuli(q->num, (n * sign) / d, &r->num);
(void) zdivi(q->den, d, &r->den);
return r;
}
/*
* Divide two numbers (as fractions).
* q3 = qqdiv(q1, q2);
*/
NUMBER *
qqdiv(NUMBER *q1, NUMBER *q2)
{
NUMBER temp;
if (qiszero(q2)) {
math_error("Division by zero");
not_reached();
}
if ((q1 == q2) || !qcmp(q1, q2))
return qlink(&_qone_);
if (qisone(q1))
return qinv(q2);
temp.num = q2->den;
temp.den = q2->num;
temp.num.sign = temp.den.sign;
temp.den.sign = 0;
temp.links = 1;
return qmul(q1, &temp);
}
/*
* Divide a number by a small integer.
* q2 = qdivi(q1, n);
*/
NUMBER *
qdivi(NUMBER *q, long n)
{
NUMBER *r;
long d; /* gcd of divisor and numerator */
int sign;
if (n == 0) {
math_error("Division by zero");
not_reached();
}
if ((n == 1) || qiszero(q))
return qlink(q);
sign = 1;
if (n < 0) {
n = -n;
sign = -1;
}
r = qalloc();
d = zmodi(q->num, n);
d = iigcd(d, n);
(void) zdivi(q->num, d * sign, &r->num);
zmuli(q->den, n / d, &r->den);
return r;
}
/*
* Return the integer quotient of a pair of numbers
* If q1/q2 is an integer qquo(q1, q2) returns this integer
* If q2 is zero, zero is returned
* In other cases whether rounding is down, up, towards zero, etc.
* is determined by rnd.
*/
NUMBER *
qquo(NUMBER *q1, NUMBER *q2, long rnd)
{
ZVALUE tmp, tmp1, tmp2;
NUMBER *q;
if (qiszero(q1) || qiszero(q2))
return qlink(&_qzero_);
if (qisint(q1) && qisint(q2)) {
zquo(q1->num, q2->num, &tmp, rnd);
} else {
zmul(q1->num, q2->den, &tmp1);
zmul(q2->num, q1->den, &tmp2);
zquo(tmp1, tmp2, &tmp, rnd);
zfree(tmp1);
zfree(tmp2);
}
if (ziszero(tmp)) {
zfree(tmp);
return qlink(&_qzero_);
}
q = qalloc();
q->num = tmp;
return q;
}
/*
* Return the absolute value of a number.
* q2 = qqabs(q1);
*/
NUMBER *
qqabs(NUMBER *q)
{
register NUMBER *r;
if (q->num.sign == 0)
return qlink(q);
r = qalloc();
if (!zisunit(q->num))
zcopy(q->num, &r->num);
if (!zisunit(q->den))
zcopy(q->den, &r->den);
r->num.sign = 0;
return r;
}
/*
* Negate a number.
* q2 = qneg(q1);
*/
NUMBER *
qneg(NUMBER *q)
{
register NUMBER *r;
if (qiszero(q))
return qlink(&_qzero_);
r = qalloc();
if (!zisunit(q->num))
zcopy(q->num, &r->num);
if (!zisunit(q->den))
zcopy(q->den, &r->den);
r->num.sign = !q->num.sign;
return r;
}
/*
* Return the sign of a number (-1, 0 or 1)
*/
NUMBER *
qsign(NUMBER *q)
{
if (qiszero(q))
return qlink(&_qzero_);
if (qisneg(q))
return qlink(&_qnegone_);
return qlink(&_qone_);
}
/*
* Invert a number.
* q2 = qinv(q1);
*/
NUMBER *
qinv(NUMBER *q)
{
register NUMBER *r;
if (qisunit(q)) {
r = (qisneg(q) ? &_qnegone_ : &_qone_);
return qlink(r);
}
if (qiszero(q)) {
math_error("Division by zero");
not_reached();
}
r = qalloc();
if (!zisunit(q->num))
zcopy(q->num, &r->den);
if (!zisunit(q->den))
zcopy(q->den, &r->num);
r->num.sign = q->num.sign;
r->den.sign = 0;
return r;
}
/*
* Return just the numerator of a number.
* q2 = qnum(q1);
*/
NUMBER *
qnum(NUMBER *q)
{
register NUMBER *r;
if (qisint(q))
return qlink(q);
if (zisunit(q->num)) {
r = (qisneg(q) ? &_qnegone_ : &_qone_);
return qlink(r);
}
r = qalloc();
zcopy(q->num, &r->num);
return r;
}
/*
* Return just the denominator of a number.
* q2 = qden(q1);
*/
NUMBER *
qden(NUMBER *q)
{
register NUMBER *r;
if (qisint(q))
return qlink(&_qone_);
r = qalloc();
zcopy(q->den, &r->num);
return r;
}
/*
* Return the fractional part of a number.
* q2 = qfrac(q1);
*/
NUMBER *
qfrac(NUMBER *q)
{
register NUMBER *r;
if (qisint(q))
return qlink(&_qzero_);
if ((q->num.len < q->den.len) || ((q->num.len == q->den.len) &&
(q->num.v[q->num.len - 1] < q->den.v[q->num.len - 1])))
return qlink(q);
r = qalloc();
zmod(q->num, q->den, &r->num, 2);
zcopy(q->den, &r->den);
return r;
}
/*
* Return the integral part of a number.
* q2 = qint(q1);
*/
NUMBER *
qint(NUMBER *q)
{
register NUMBER *r;
if (qisint(q))
return qlink(q);
if ((q->num.len < q->den.len) || ((q->num.len == q->den.len) &&
(q->num.v[q->num.len - 1] < q->den.v[q->num.len - 1])))
return qlink(&_qzero_);
r = qalloc();
zquo(q->num, q->den, &r->num, 2);
return r;
}
/*
* Compute the square of a number.
*/
NUMBER *
qsquare(NUMBER *q)
{
ZVALUE num, zden;
if (qiszero(q))
return qlink(&_qzero_);
if (qisunit(q))
return qlink(&_qone_);
num = q->num;
zden = q->den;
q = qalloc();
if (!zisunit(num))
zsquare(num, &q->num);
if (!zisunit(zden))
zsquare(zden, &q->den);
return q;
}
/*
* Shift an integer by a given number of bits. This multiplies the number
* by the appropriate power of two. Positive numbers shift left, negative
* ones shift right. Low bits are truncated when shifting right.
*/
NUMBER *
qshift(NUMBER *q, long n)
{
register NUMBER *r;
if (qisfrac(q)) {
math_error("Shift of non-integer");
not_reached();
}
if (qiszero(q) || (n == 0))
return qlink(q);
if (n <= -(q->num.len * BASEB))
return qlink(&_qzero_);
r = qalloc();
zshift(q->num, n, &r->num);
return r;
}
/*
* Scale a number by a power of two, as in:
* ans = q * 2^n.
* This is similar to shifting, except that fractions work.
*/
NUMBER *
qscale(NUMBER *q, long pow)
{
long numshift, denshift, tmp;
NUMBER *r;
if (qiszero(q) || (pow == 0))
return qlink(q);
numshift = zisodd(q->num) ? 0 : zlowbit(q->num);
denshift = zisodd(q->den) ? 0 : zlowbit(q->den);
if (pow > 0) {
tmp = pow;
if (tmp > denshift)
tmp = denshift;
denshift = -tmp;
numshift = (pow - tmp);
} else {
pow = -pow;
tmp = pow;
if (tmp > numshift)
tmp = numshift;
numshift = -tmp;
denshift = (pow - tmp);
}
r = qalloc();
if (numshift)
zshift(q->num, numshift, &r->num);
else
zcopy(q->num, &r->num);
if (denshift)
zshift(q->den, denshift, &r->den);
else
zcopy(q->den, &r->den);
return r;
}
/*
* Return the minimum of two numbers.
*/
NUMBER *
qmin(NUMBER *q1, NUMBER *q2)
{
if (q1 == q2)
return qlink(q1);
if (qrel(q1, q2) > 0)
q1 = q2;
return qlink(q1);
}
/*
* Return the maximum of two numbers.
*/
NUMBER *
qmax(NUMBER *q1, NUMBER *q2)
{
if (q1 == q2)
return qlink(q1);
if (qrel(q1, q2) < 0)
q1 = q2;
return qlink(q1);
}
/*
* Perform the bitwise OR of two integers.
*/
NUMBER *
qor(NUMBER *q1, NUMBER *q2)
{
register NUMBER *r;
NUMBER *q1tmp, *q2tmp, *q;
if (qisfrac(q1) || qisfrac(q2)) {
math_error("Non-integers for bitwise or");
not_reached();
}
if (qcmp(q1,q2) == 0 || qiszero(q2))
return qlink(q1);
if (qiszero(q1))
return qlink(q2);
if (qisneg(q1)) {
q1tmp = qcomp(q1);
if (qisneg(q2)) {
q2tmp = qcomp(q2);
q = qand(q1tmp,q2tmp);
r = qcomp(q);
qfree(q1tmp);
qfree(q2tmp);
qfree(q);
return r;
}
q = qandnot(q1tmp, q2);
qfree(q1tmp);
r = qcomp(q);
qfree(q);
return r;
}
if (qisneg(q2)) {
q2tmp = qcomp(q2);
q = qandnot(q2tmp, q1);
qfree(q2tmp);
r = qcomp(q);
qfree(q);
return r;
}
r = qalloc();
zor(q1->num, q2->num, &r->num);
return r;
}
/*
* Perform the bitwise AND of two integers.
*/
NUMBER *
qand(NUMBER *q1, NUMBER *q2)
{
register NUMBER *r;
NUMBER *q1tmp, *q2tmp, *q;
ZVALUE res;
if (qisfrac(q1) || qisfrac(q2)) {
math_error("Non-integers for bitwise and");
not_reached();
}
if (qcmp(q1, q2) == 0)
return qlink(q1);
if (qiszero(q1) || qiszero(q2))
return qlink(&_qzero_);
if (qisneg(q1)) {
q1tmp = qcomp(q1);
if (qisneg(q2)) {
q2tmp = qcomp(q2);
q = qor(q1tmp, q2tmp);
qfree(q1tmp);
qfree(q2tmp);
r = qcomp(q);
qfree(q);
return r;
}
r = qandnot(q2, q1tmp);
qfree(q1tmp);
return r;
}
if (qisneg(q2)) {
q2tmp = qcomp(q2);
r = qandnot(q1, q2tmp);
qfree(q2tmp);
return r;
}
zand(q1->num, q2->num, &res);
if (ziszero(res)) {
zfree(res);
return qlink(&_qzero_);
}
r = qalloc();
r->num = res;
return r;
}
/*
* Perform the bitwise XOR of two integers.
*/
NUMBER *
qxor(NUMBER *q1, NUMBER *q2)
{
register NUMBER *r;
NUMBER *q1tmp, *q2tmp, *q;
ZVALUE res;
if (qisfrac(q1) || qisfrac(q2)) {
math_error("Non-integers for bitwise xor");
not_reached();
}
if (qcmp(q1,q2) == 0)
return qlink(&_qzero_);
if (qiszero(q1))
return qlink(q2);
if (qiszero(q2))
return qlink(q1);
if (qisneg(q1)) {
q1tmp = qcomp(q1);
if (qisneg(q2)) {
q2tmp = qcomp(q2);
r = qxor(q1tmp, q2tmp);
qfree(q1tmp);
qfree(q2tmp);
return r;
}
q = qxor(q1tmp, q2);
qfree(q1tmp);
r = qcomp(q);
qfree(q);
return r;
}
if (qisneg(q2)) {
q2tmp = qcomp(q2);
q = qxor(q1, q2tmp);
qfree(q2tmp);
r = qcomp(q);
qfree(q);
return r;
}
zxor(q1->num, q2->num, &res);
if (ziszero(res)) {
zfree(res);
return qlink(&_qzero_);
}
r = qalloc();
r->num = res;
return r;
}
/*
* Perform the bitwise AND-NOT of two integers.
*/
NUMBER *
qandnot(NUMBER *q1, NUMBER *q2)
{
register NUMBER *r;
NUMBER *q1tmp, *q2tmp, *q;
if (qisfrac(q1) || qisfrac(q2)) {
math_error("Non-integers for bitwise xor");
not_reached();
}
if (qcmp(q1,q2) == 0 || qiszero(q1))
return qlink(&_qzero_);
if (qiszero(q2))
return qlink(q1);
if (qisneg(q1)) {
q1tmp = qcomp(q1);
if (qisneg(q2)) {
q2tmp = qcomp(q2);
r = qandnot(q2tmp, q1tmp);
qfree(q1tmp);
qfree(q2tmp);
return r;
}
q = qor(q1tmp, q2);
qfree(q1tmp);
r = qcomp(q);
qfree(q);
return r;
}
if (qisneg(q2)) {
q2tmp = qcomp(q2);
r = qand(q1, q2tmp);
qfree(q2tmp);
return r;
}
r = qalloc();
zandnot(q1->num, q2->num, &r->num);
return r;
}
/*
* Return the bitwise "complement" of a number. This is - q -1 if q is an
* integer, - q otherwise.
*/
NUMBER *
qcomp(NUMBER *q)
{
NUMBER *qtmp;
NUMBER *res;
if (qiszero(q))
return qlink(&_qnegone_);
if (qisnegone(q))
return qlink(&_qzero_);
qtmp = qneg(q);
if (qisfrac(q))
return qtmp;
res = qdec(qtmp);
qfree(qtmp);
return res;
}
/*
* Return the number whose binary representation only has the specified
* bit set (counting from zero). This thus produces a given power of two.
*/
NUMBER *
qbitvalue(long n)
{
register NUMBER *r;
if (n == 0)
return qlink(&_qone_);
r = qalloc();
if (n > 0)
zbitvalue(n, &r->num);
else
zbitvalue(-n, &r->den);
return r;
}
/*
* Return 10^n
*/
NUMBER *
qtenpow(long n)
{
register NUMBER *r;
if (n == 0)
return qlink(&_qone_);
r = qalloc();
if (n > 0)
ztenpow(n, &r->num);
else
ztenpow(-n, &r->den);
return r;
}
/*
* Return the precision of a number (usually for examining an epsilon value).
* The precision of a number e less than 1 is the positive
* integer p for which e = 2^-p * f, where 1 <= f < 2.
* Numbers greater than or equal to one have a precision of zero.
* For example, the precision of e is 6 if 1/64 <= e < 1/32.
*/
long
qprecision(NUMBER *q)
{
long r;
if (qiszero(q) || qisneg(q)) {
math_error("Non-positive number for precision");
not_reached();
}
r = - qilog2(q);
return (r < 0 ? 0 : r);
}
/*
* Determine whether or not one number exactly divides another one.
* Returns true if the first number is an integer multiple of the second one.
*/
bool
qdivides(NUMBER *q1, NUMBER *q2)
{
if (qiszero(q1))
return true;
if (qisint(q1) && qisint(q2)) {
if (qisunit(q2))
return true;
return zdivides(q1->num, q2->num);
}
return zdivides(q1->num, q2->num) && zdivides(q2->den, q1->den);
}
/*
* Compare two numbers and return an integer indicating their relative size.
* i = qrel(q1, q2);
*/
FLAG
qrel(NUMBER *q1, NUMBER *q2)
{
ZVALUE z1, z2;
long wc1, wc2;
int sign;
int z1f = 0, z2f = 0;
if (q1 == q2)
return 0;
sign = q2->num.sign - q1->num.sign;
if (sign)
return sign;
if (qiszero(q2))
return !qiszero(q1);
if (qiszero(q1))
return -1;
/*
* Make a quick comparison by calculating the number of words
* resulting as if we multiplied through by the denominators,
* and then comparing the word counts.
*/
sign = 1;
if (qisneg(q1))
sign = -1;
wc1 = q1->num.len + q2->den.len;
wc2 = q2->num.len + q1->den.len;
if (wc1 < wc2 - 1)
return -sign;
if (wc2 < wc1 - 1)
return sign;
/*
* Quick check failed, must actually do the full comparison.
*/
if (zisunit(q2->den)) {
z1 = q1->num;
} else if (zisone(q1->num)) {
z1 = q2->den;
} else {
z1f = 1;
zmul(q1->num, q2->den, &z1);
}
if (zisunit(q1->den)) {
z2 = q2->num;
} else if (zisone(q2->num)) {
z2 = q1->den;
} else {
z2f = 1;
zmul(q2->num, q1->den, &z2);
}
sign = zrel(z1, z2);
if (z1f)
zfree(z1);
if (z2f)
zfree(z2);
return sign;
}
/*
* Compare two numbers to see if they are equal.
* This differs from qrel in that the numbers are not ordered.
* Returns true if they differ.
*/
bool
qcmp(NUMBER *q1, NUMBER *q2)
{
if (q1 == q2)
return false;
if ((q1->num.sign != q2->num.sign) || (q1->num.len != q2->num.len) ||
(q1->den.len != q2->den.len) || (*q1->num.v != *q2->num.v) ||
(*q1->den.v != *q2->den.v))
return true;
if (zcmp(q1->num, q2->num))
return true;
if (qisint(q1))
return false;
return zcmp(q1->den, q2->den);
}
/*
* Compare a number against a normal small integer.
* Returns 1, 0, or -1, according to whether the first number is greater,
* equal, or less than the second number.
* res = qreli(q, n);
*/
FLAG
qreli(NUMBER *q, long n)
{
ZVALUE z1, z2;
FLAG res;
if (qiszero(q))
return ((n > 0) ? -1 : (n < 0));
if (n == 0)
return (q->num.sign ? -1 : 0);
if (q->num.sign != (n < 0))
return ((n < 0) ? 1 : -1);
itoz(n, &z1);
if (qisfrac(q)) {
zmul(q->den, z1, &z2);
zfree(z1);
z1 = z2;
}
res = zrel(q->num, z1);
zfree(z1);
return res;
}
/*
* Compare a number against a small integer to see if they are equal.
* Returns true if they differ.
*/
bool
qcmpi(NUMBER *q, long n)
{
long len;
#if LONG_BITS > BASEB
FULL nf;
#endif
len = q->num.len;
if (qisfrac(q) || (q->num.sign != (n < 0)))
return true;
if (n < 0)
n = -n;
if (((HALF)(n)) != q->num.v[0])
return true;
#if LONG_BITS > BASEB
nf = ((FULL) n) >> BASEB;
return ((nf != 0 || len > 1) && (len != 2 || nf != q->num.v[1]));
#else
return (len > 1);
#endif
}
/*
* Number node allocation routines
*/
#define NNALLOC 1000
STATIC NUMBER *freeNum = NULL;
STATIC NUMBER **firstNums = NULL;
STATIC long blockcount = 0;
NUMBER *
qalloc(void)
{
NUMBER *temp;
NUMBER ** newfn;
if (freeNum == NULL) {
freeNum = (NUMBER *) malloc(sizeof (NUMBER) * NNALLOC);
if (freeNum == NULL) {
math_error("Not enough memory");
not_reached();
}
freeNum[NNALLOC - 1].next = NULL;
freeNum[NNALLOC - 1].links = 0;
/*
* We prevent the temp pointer from walking behind freeNum
* by stopping one short of the end and running the loop one
* more time.
*
* We would stop the loop with just temp >= freeNum, but
* doing this helps make code checkers such as insure happy.
*/
for (temp = freeNum + NNALLOC - 2; temp > freeNum; --temp) {
temp->next = temp + 1;
temp->links = 0;
}
/* run the loop manually one last time */
temp->next = temp + 1;
temp->links = 0;
blockcount++;
if (firstNums == NULL) {
newfn = (NUMBER **) malloc(blockcount * sizeof(NUMBER *));
} else {
newfn = (NUMBER **)
realloc(firstNums, blockcount * sizeof(NUMBER *));
}
if (newfn == NULL) {
math_error("Cannot allocate new number block");
not_reached();
}
firstNums = newfn;
firstNums[blockcount - 1] = freeNum;
}
temp = freeNum;
freeNum = temp->next;
temp->links = 1;
temp->num = _one_;
temp->den = _one_;
return temp;
}
void
qfreenum(NUMBER *q)
{
if (q == NULL) {
math_error("Calling qfreenum with null argument!!!");
not_reached();
}
if (q->links != 0) {
math_error("Calling qfreenum with non-zero links!!!");
not_reached();
}
zfree(q->num);
zfree(q->den);
q->next = freeNum;
freeNum = q;
}
void
shownumbers(void)
{
NUMBER *vp;
long i, j, k;
long count = 0;
printf("Index Links Digits Value\n");
printf("----- ----- ------ -----\n");
for (i = 0, k = 0; initnumbs[i] != NULL; i++) {
count++;
vp = initnumbs[i];
printf("%6ld %4ld ", k++, vp->links);
fitprint(vp, 40);
printf("\n");
}
for (i = 0; i < blockcount; i++) {
vp = firstNums[i];
for (j = 0; j < NNALLOC; j++, k++, vp++) {
if (vp->links > 0) {
count++;
printf("%6ld %4ld ", k, vp->links);
fitprint(vp, 40);
printf("\n");
}
}
}
printf("\nNumber: %ld\n", count);
}