conterm/libmp/mptouv.c

50 lines
727 B
C

#include "os.h"
#include <mp.h>
#include "dat.h"
#define VLDIGITS (sizeof(vlong)/sizeof(mpdigit))
/*
* this code assumes that a vlong is an integral number of
* mpdigits long.
*/
mpint*
uvtomp(uvlong v, mpint *b)
{
int s;
if(b == nil)
b = mpnew(VLDIGITS*sizeof(mpdigit));
else
mpbits(b, VLDIGITS*sizeof(mpdigit));
mpassign(mpzero, b);
if(v == 0)
return b;
for(s = 0; s < VLDIGITS && v != 0; s++){
b->p[s] = v;
v >>= sizeof(mpdigit)*8;
}
b->top = s;
return b;
}
uvlong
mptouv(mpint *b)
{
uvlong v;
int s;
if(b->top == 0)
return (vlong) 0;
mpnorm(b);
if(b->top > VLDIGITS)
return MAXVLONG;
v = (uvlong) 0;
for(s = 0; s < b->top; s++)
v |= b->p[s]<<(s*sizeof(mpdigit)*8);
return v;
}