#include "os.h"#include <mp.h> /* operands need to have m->top+1 digits of space and satisfy 0 ≤ a ≤ m-1 */static mpint*modarg(mpint *a, mpint *m){	if(a->size <= m->top || a->sign < 0 || mpmagcmp(a, m) >= 0){		a = mpcopy(a);		mpmod(a, m, a);		mpbits(a, Dbits*(m->top+1));		a->top = m->top;	} else if(a->top < m->top){		memset(&a->p[a->top], 0, (m->top - a->top)*Dbytes);	}	return a;} voidmpmodadd(mpint *b1, mpint *b2, mpint *m, mpint *sum){	mpint *a, *b;	mpdigit d;	int i, j; 	a = modarg(b1, m);	b = modarg(b2, m); 	sum->flags |= (a->flags | b->flags) & MPtimesafe;	mpbits(sum, Dbits*2*(m->top+1)); 	mpvecadd(a->p, m->top, b->p, m->top, sum->p);	mpvecsub(sum->p, m->top+1, m->p, m->top, sum->p+m->top+1); 	d = sum->p[2*m->top+1];	for(i = 0, j = m->top+1; i < m->top; i++, j++)		sum->p[i] = (sum->p[i] & d) | (sum->p[j] & ~d); 	sum->top = m->top;	sum->sign = 1;	mpnorm(sum); 	if(a != b1)		mpfree(a);	if(b != b2)		mpfree(b);} voidmpmodsub(mpint *b1, mpint *b2, mpint *m, mpint *diff){	mpint *a, *b;	mpdigit d;	int i, j; 	a = modarg(b1, m);	b = modarg(b2, m); 	diff->flags |= (a->flags | b->flags) & MPtimesafe;	mpbits(diff, Dbits*2*(m->top+1)); 	a->p[m->top] = 0;	mpvecsub(a->p, m->top+1, b->p, m->top, diff->p);	mpvecadd(diff->p, m->top, m->p, m->top, diff->p+m->top+1); 	d = ~diff->p[m->top];	for(i = 0, j = m->top+1; i < m->top; i++, j++)		diff->p[i] = (diff->p[i] & d) | (diff->p[j] & ~d); 	diff->top = m->top;	diff->sign = 1;	mpnorm(diff); 	if(a != b1)		mpfree(a);	if(b != b2)		mpfree(b);} voidmpmodmul(mpint *b1, mpint *b2, mpint *m, mpint *prod){	mpint *a, *b; 	a = modarg(b1, m);	b = modarg(b2, m); 	mpmul(a, b, prod);	mpmod(prod, m, prod); 	if(a != b1)		mpfree(a);	if(b != b2)		mpfree(b);}