1 b3f61791 2004-03-21 devnull #include "os.h"
 2 b3f61791 2004-03-21 devnull #include <mp.h>
 3 b3f61791 2004-03-21 devnull #include "dat.h"
 4 b3f61791 2004-03-21 devnull 
 5 b3f61791 2004-03-21 devnull #define VLDIGITS (sizeof(vlong)/sizeof(mpdigit))
 6 b3f61791 2004-03-21 devnull 
 7 b3f61791 2004-03-21 devnull /*
 8 b3f61791 2004-03-21 devnull  *  this code assumes that a vlong is an integral number of
 9 b3f61791 2004-03-21 devnull  *  mpdigits long.
10 b3f61791 2004-03-21 devnull  */
11 b3f61791 2004-03-21 devnull mpint*
12 b3f61791 2004-03-21 devnull vtomp(vlong v, mpint *b)
13 b3f61791 2004-03-21 devnull {
14 b3f61791 2004-03-21 devnull 	int s;
15 b3f61791 2004-03-21 devnull 	uvlong uv;
16 b3f61791 2004-03-21 devnull 
17 b3f61791 2004-03-21 devnull 	if(b == nil)
18 b3f61791 2004-03-21 devnull 		b = mpnew(VLDIGITS*sizeof(mpdigit));
19 b3f61791 2004-03-21 devnull 	else
20 b3f61791 2004-03-21 devnull 		mpbits(b, VLDIGITS*sizeof(mpdigit));
21 b3f61791 2004-03-21 devnull 	mpassign(mpzero, b);
22 b3f61791 2004-03-21 devnull 	if(v == 0)
23 b3f61791 2004-03-21 devnull 		return b;
24 b3f61791 2004-03-21 devnull 	if(v < 0){
25 b3f61791 2004-03-21 devnull 		b->sign = -1;
26 b3f61791 2004-03-21 devnull 		uv = -v;
27 b3f61791 2004-03-21 devnull 	} else
28 b3f61791 2004-03-21 devnull 		uv = v;
29 b3f61791 2004-03-21 devnull 	for(s = 0; s < VLDIGITS && uv != 0; s++){
30 b3f61791 2004-03-21 devnull 		b->p[s] = uv;
31 bcb7f64e 2006-04-20 devnull 	/* !@*$&!@$ gcc gives warnings about the >> here
32 fa325e9b 2020-01-10 cross 	 * when running on 64-bit machines, even though
33 bcb7f64e 2006-04-20 devnull 	 * it's in dead code.  fake it out with two shifts.
34 9e36143a 2005-12-30 devnull 		if(sizeof(mpdigit) == sizeof(uvlong))
35 9e36143a 2005-12-30 devnull 			uv = 0;
36 9e36143a 2005-12-30 devnull 		else
37 9e36143a 2005-12-30 devnull 			uv >>= sizeof(mpdigit)*8;
38 bcb7f64e 2006-04-20 devnull 	*/
39 bcb7f64e 2006-04-20 devnull 		uv >>= sizeof(mpdigit)*4;
40 bcb7f64e 2006-04-20 devnull 		uv >>= sizeof(mpdigit)*4;
41 b3f61791 2004-03-21 devnull 	}
42 b3f61791 2004-03-21 devnull 	b->top = s;
43 b3f61791 2004-03-21 devnull 	return b;
44 b3f61791 2004-03-21 devnull }
45 b3f61791 2004-03-21 devnull 
46 b3f61791 2004-03-21 devnull vlong
47 b3f61791 2004-03-21 devnull mptov(mpint *b)
48 b3f61791 2004-03-21 devnull {
49 b3f61791 2004-03-21 devnull 	uvlong v;
50 b3f61791 2004-03-21 devnull 	int s;
51 b3f61791 2004-03-21 devnull 
52 b3f61791 2004-03-21 devnull 	if(b->top == 0)
53 b3f61791 2004-03-21 devnull 		return 0LL;
54 b3f61791 2004-03-21 devnull 
55 b3f61791 2004-03-21 devnull 	mpnorm(b);
56 b3f61791 2004-03-21 devnull 	if(b->top > VLDIGITS){
57 b3f61791 2004-03-21 devnull 		if(b->sign > 0)
58 b3f61791 2004-03-21 devnull 			return (vlong)MAXVLONG;
59 b3f61791 2004-03-21 devnull 		else
60 b3f61791 2004-03-21 devnull 			return (vlong)MINVLONG;
61 b3f61791 2004-03-21 devnull 	}
62 b3f61791 2004-03-21 devnull 
63 b3f61791 2004-03-21 devnull 	v = 0ULL;
64 b3f61791 2004-03-21 devnull 	for(s = 0; s < b->top; s++)
65 b3f61791 2004-03-21 devnull 		v |= b->p[s]<<(s*sizeof(mpdigit)*8);
66 b3f61791 2004-03-21 devnull 
67 b3f61791 2004-03-21 devnull 	if(b->sign > 0){
68 b3f61791 2004-03-21 devnull 		if(v > MAXVLONG)
69 b3f61791 2004-03-21 devnull 			v = MAXVLONG;
70 b3f61791 2004-03-21 devnull 	} else {
71 b3f61791 2004-03-21 devnull 		if(v > MINVLONG)
72 b3f61791 2004-03-21 devnull 			v = MINVLONG;
73 b3f61791 2004-03-21 devnull 		else
74 b3f61791 2004-03-21 devnull 			v = -(vlong)v;
75 b3f61791 2004-03-21 devnull 	}
76 b3f61791 2004-03-21 devnull 
77 b3f61791 2004-03-21 devnull 	return (vlong)v;
78 b3f61791 2004-03-21 devnull }