jehanne/sys/src/lib/mp/port/mptouv.c

48 lines
744 B
C

#include "os.h"
#include <mp.h>
#include "dat.h"
#define VLDIGITS (sizeof(int64_t)/sizeof(mpdigit))
/*
* this code assumes that a int64_t is an integral number of
* mpdigits int32_t.
*/
mpint*
uvtomp(uint64_t v, mpint *b)
{
int s;
if(b == nil){
b = mpnew(VLDIGITS*sizeof(mpdigit));
jehanne_setmalloctag(b, jehanne_getcallerpc());
}else
mpbits(b, VLDIGITS*sizeof(mpdigit));
b->sign = 1;
for(s = 0; s < VLDIGITS; s++){
b->p[s] = v;
v >>= sizeof(mpdigit)*8;
}
b->top = s;
return mpnorm(b);
}
uint64_t
mptouv(mpint *b)
{
uint64_t v;
int s;
if(b->top == 0)
return 0LL;
if(b->top > VLDIGITS)
return MAXVLONG;
v = 0ULL;
for(s = 0; s < b->top; s++)
v |= (uint64_t)b->p[s]<<(s*sizeof(mpdigit)*8);
return v;
}