1 #include "os.h"
2 #include <mp.h>
3 #include "dat.h"
4 
5 #define VLDIGITS (sizeof(vlong)/sizeof(mpdigit))
6 
7 /*
8  *  this code assumes that a vlong is an integral number of
9  *  mpdigits long.
10  */
11 mpint*
12 uvtomp(uvlong v, mpint *b)
13 {
14 	int s;
15 
16 	if(b == nil)
17 		b = mpnew(VLDIGITS*sizeof(mpdigit));
18 	else
19 		mpbits(b, VLDIGITS*sizeof(mpdigit));
20 	mpassign(mpzero, b);
21 	if(v == 0)
22 		return b;
23 	for(s = 0; s < VLDIGITS && v != 0; s++){
24 		b->p[s] = v;
25 	/* !@*$&!@$ gcc gives warnings about the >> here
26 	 * when running on 64-bit machines, even though
27 	 * it's in dead code.  fake it out with two shifts.
28 		if(sizeof(mpdigit) == sizeof(uvlong))
29 			v = 0;
30 		else
31 			v >>= sizeof(mpdigit)*8;
32 	*/
33 		v >>= sizeof(mpdigit)*4;
34 		v >>= sizeof(mpdigit)*4;
35 	}
36 	b->top = s;
37 	return b;
38 }
39 
40 uvlong
41 mptouv(mpint *b)
42 {
43 	uvlong v;
44 	int s;
45 
46 	if(b->top == 0)
47 		return 0LL;
48 
49 	mpnorm(b);
50 	if(b->top > VLDIGITS)
51 		return MAXVLONG;
52 
53 	v = 0ULL;
54 	for(s = 0; s < b->top; s++)
55 		v |= (uvlong)b->p[s]<<(s*sizeof(mpdigit)*8);
56 
57 	return v;
58 }