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Arquivotheca.Solaris-2.5/lib/libmp/madd.c
seta75D 7c4988eac0 Init
2021-10-11 19:38:01 -03:00

198 lines
3.2 KiB
C
Executable File

/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/* THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T */
/* The copyright notice above does not evidence any */
/* actual or intended publication of such source code. */
/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
/* Portions Copyright(c) 1988, Sun Microsystems Inc. */
/* All Rights Reserved */
#ident "@(#)madd.c 1.2 90/02/20 SMI" /* SVr4.0 1.1 */
/* LINTLIBRARY */
#include <mp.h>
m_add(a,b,c)
register struct mint *a,*b,*c;
{
register int carry,i;
register int x;
register short *cval;
cval = xalloc(a->len + 1,"m_add");
carry = 0;
for (i = 0; i < b->len; i++) {
x = carry + a->val[i] + b->val[i];
if ( x & 0100000) {
carry = 1;
cval[i] = x & 077777;
} else {
carry = 0;
cval[i] = x;
}
}
for (; i < a->len; i++) {
x = carry + a->val[i];
if (x & 0100000) {
cval[i] = x & 077777;
} else {
carry = 0;
cval[i] = x;
}
}
if (carry == 1) {
cval[i] = 1;
c->len = i + 1;
} else {
c->len = a->len;
}
c->val = cval;
if (c->len == 0) {
free((char *) cval);
}
}
madd(a,b,c)
register struct mint *a,*b,*c;
{
struct mint x,y;
int sign;
x.len = y.len = 0;
_mp_move(a, &x);
_mp_move(b, &y);
xfree(c);
sign = 1;
if (x.len >= 0) {
if(y.len >= 0) {
if (x.len >= y.len) {
m_add(&x,&y,c);
} else {
m_add(&y,&x,c);
}
} else {
y.len = -y.len;
msub(&x,&y,c);
}
} else {
if (y.len <= 0) {
x.len = -x.len;
y.len = -y.len;
sign = -1;
madd(&x,&y,c);
} else {
x.len = -x.len;
msub(&y,&x,c);
}
}
c->len = sign * c->len;
xfree(&x);
xfree(&y);
}
m_sub(a,b,c)
register struct mint *a,*b,*c;
{
register int x,i;
register int borrow;
short one;
struct mint mone;
one = 1;
mone.len = 1;
mone.val = &one;
c->val = xalloc(a->len,"m_sub");
borrow = 0;
for (i = 0; i < b->len; i++) {
x = borrow + a->val[i] - b->val[i];
if (x & 0100000) {
borrow = -1;
c->val[i] = x & 077777;
} else {
borrow = 0;
c->val[i] = x;
}
}
for(; i < a->len; i++) {
x = borrow + a->val[i];
if (x & 0100000) {
c->val[i] = x & 077777;
} else {
borrow = 0;
c->val[i] = x;
}
}
if (borrow < 0) {
for (i = 0; i < a->len; i++) {
c->val[i] ^= 077777;
}
c->len = a->len;
madd(c,&mone,c);
}
for(i = a->len-1; i >= 0; --i) {
if (c->val[i] > 0) {
if (borrow == 0) {
c->len = i + 1;
} else {
c->len= -i - 1;
}
return;
}
}
free((char *) c->val);
}
msub(a,b,c)
register struct mint *a,*b,*c;
{
struct mint x,y;
int sign;
x.len = y.len = 0;
_mp_move(a, &x);
_mp_move(b, &y);
xfree(c);
sign = 1;
if (x.len >= 0) {
if (y.len >= 0) {
if (x.len >= y.len) {
m_sub(&x,&y,c);
} else {
sign = -1;
msub(&y,&x,c);
}
} else {
y.len = -y.len;
madd(&x,&y,c);
}
} else {
if (y.len <= 0) {
x.len = -x.len;
y.len = -y.len;
msub(&y,&x,c);
} else {
x.len = -x.len;
madd(&x,&y,c);
sign = -1;
}
}
c->len = sign * c->len;
xfree(&x);
xfree(&y);
}