shithub: sl

ref: 24a71723ffbe92ccbdc088a078d776fb869b52ca
dir: /3rd/mp/mptouv.c/

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#include "platform.h"
#include "mp.h"

#define VLDIGITS (int)(sizeof(s64int)/Dbytes)

/*
 *  this code assumes that a s64int is an integral number of
 *  mpdigits long.
 */
mpint*
uvtomp(u64int v, mpint *b)
{
	int s;

	if(b == nil)
		b = mpnew(VLDIGITS*Dbits);
	else
		mpbits(b, VLDIGITS*Dbits);
	b->sign = 1;
	for(s = 0; s < VLDIGITS; s++){
		b->p[s] = v;
#ifndef BITS64
		v >>= Dbits;
#endif
	}
	b->top = s;
	return mpnorm(b);
}

u64int
mptouv(mpint *b)
{
	u64int v;
	u32int s;

	if(b->top == 0 || b->sign < 0)
		return 0LL;

	if(b->top > VLDIGITS)
		return -1LL;

	v = 0ULL;
	for(s = 0; s < b->top; s++)
		v |= (u64int)b->p[s]<<(s*Dbits);

	return v;
}