xref: /plan9/sys/include/mp.h (revision 033584b01144b418519c5713cd258b3ca2f7bccf)
1 #pragma	src	"/sys/src/libmp"
2 #pragma	lib	"libmp.a"
3 
4 #define _MPINT 1
5 
6 /*
7  * the code assumes mpdigit to be at least an int
8  * mpdigit must be an atomic type.  mpdigit is defined
9  * in the architecture specific u.h
10  */
11 
12 typedef struct mpint mpint;
13 
14 struct mpint
15 {
16 	int	sign;	/* +1 or -1 */
17 	int	size;	/* allocated digits */
18 	int	top;	/* significant digits */
19 	mpdigit	*p;
20 	char	flags;
21 };
22 
23 enum
24 {
25 	MPstatic=	0x01,
26 	Dbytes=		sizeof(mpdigit),	/* bytes per digit */
27 	Dbits=		Dbytes*8		/* bits per digit */
28 };
29 
30 /* allocation */
31 void	mpsetminbits(int n);	/* newly created mpint's get at least n bits */
32 mpint*	mpnew(int n);		/* create a new mpint with at least n bits */
33 void	mpfree(mpint *b);
34 void	mpbits(mpint *b, int n);	/* ensure that b has at least n bits */
35 void	mpnorm(mpint *b);		/* dump leading zeros */
36 mpint*	mpcopy(mpint *b);
37 void	mpassign(mpint *old, mpint *new);
38 
39 /* random bits */
40 mpint*	mprand(int bits, void (*gen)(uchar*, int), mpint *b);
41 
42 /* conversion */
43 mpint*	strtomp(char*, char**, int, mpint*);	/* ascii */
44 int	mpfmt(Fmt*);
45 char*	mptoa(mpint*, int, char*, int);
46 mpint*	letomp(uchar*, uint, mpint*);	/* byte array, little-endian */
47 int	mptole(mpint*, uchar*, uint, uchar**);
48 mpint*	betomp(uchar*, uint, mpint*);	/* byte array, little-endian */
49 int	mptobe(mpint*, uchar*, uint, uchar**);
50 uint	mptoui(mpint*);			/* unsigned int */
51 mpint*	uitomp(uint, mpint*);
52 int	mptoi(mpint*);			/* int */
53 mpint*	itomp(int, mpint*);
54 uvlong	mptouv(mpint*);			/* unsigned vlong */
55 mpint*	uvtomp(uvlong, mpint*);
56 vlong	mptov(mpint*);			/* vlong */
57 mpint*	vtomp(vlong, mpint*);
58 
59 /* divide 2 digits by one */
60 void	mpdigdiv(mpdigit *dividend, mpdigit divisor, mpdigit *quotient);
61 
62 /* in the following, the result mpint may be */
63 /* the same as one of the inputs. */
64 void	mpadd(mpint *b1, mpint *b2, mpint *sum);	/* sum = b1+b2 */
65 void	mpsub(mpint *b1, mpint *b2, mpint *diff);	/* diff = b1-b2 */
66 void	mpleft(mpint *b, int shift, mpint *res);	/* res = b<<shift */
67 void	mpright(mpint *b, int shift, mpint *res);	/* res = b>>shift */
68 void	mpmul(mpint *b1, mpint *b2, mpint *prod);	/* prod = b1*b2 */
69 void	mpexp(mpint *b, mpint *e, mpint *m, mpint *res);	/* res = b**e mod m */
70 void	mpmod(mpint *b, mpint *m, mpint *remainder);	/* remainder = b mod m */
71 
72 /* quotient = dividend/divisor, remainder = dividend % divisor */
73 void	mpdiv(mpint *dividend, mpint *divisor,  mpint *quotient, mpint *remainder);
74 
75 /* return neg, 0, pos as b1-b2 is neg, 0, pos */
76 int	mpcmp(mpint *b1, mpint *b2);
77 
78 /* extended gcd return d, x, and y, s.t. d = gcd(a,b) and ax+by = d */
79 void	mpextendedgcd(mpint *a, mpint *b, mpint *d, mpint *x, mpint *y);
80 
81 /* res = b**-1 mod m */
82 void	mpinvert(mpint *b, mpint *m, mpint *res);
83 
84 /* bit counting */
85 int	mpsignif(mpint*);	/* number of sigificant bits in mantissa */
86 int	mplowbits0(mpint*);	/* k, where n = 2**k * q for odd q */
87 
88 /* well known constants */
89 extern mpint	*mpzero, *mpone, *mptwo;
90 
91 /* sum[0:alen] = a[0:alen-1] + b[0:blen-1] */
92 /* prereq: alen >= blen, sum has room for alen+1 digits */
93 void	mpvecadd(mpdigit *a, int alen, mpdigit *b, int blen, mpdigit *sum);
94 
95 /* diff[0:alen-1] = a[0:alen-1] - b[0:blen-1] */
96 /* prereq: alen >= blen, diff has room for alen digits */
97 void	mpvecsub(mpdigit *a, int alen, mpdigit *b, int blen, mpdigit *diff);
98 
99 /* p[0:n] += m * b[0:n-1] */
100 /* prereq: p has room for n+1 digits */
101 void	mpvecdigmuladd(mpdigit *b, int n, mpdigit m, mpdigit *p);
102 
103 /* p[0:n] -= m * b[0:n-1] */
104 /* prereq: p has room for n+1 digits */
105 int	mpvecdigmulsub(mpdigit *b, int n, mpdigit m, mpdigit *p);
106 
107 /* p[0:alen*blen-1] = a[0:alen-1] * b[0:blen-1] */
108 /* prereq: alen >= blen, p has room for m*n digits */
109 void	mpvecmul(mpdigit *a, int alen, mpdigit *b, int blen, mpdigit *p);
110 
111 /* sign of a - b or zero if the same */
112 int	mpveccmp(mpdigit *a, int alen, mpdigit *b, int blen);
113 
114 /* divide the 2 digit dividend by the one digit divisor and stick in quotient */
115 /* we assume that the result is one digit - overflow is all 1's */
116 void	mpdigdiv(mpdigit *dividend, mpdigit divisor, mpdigit *quotient);
117 
118 /* playing with magnitudes */
119 int	mpmagcmp(mpint *b1, mpint *b2);
120 void	mpmagadd(mpint *b1, mpint *b2, mpint *sum);	/* sum = b1+b2 */
121 void	mpmagsub(mpint *b1, mpint *b2, mpint *sum);	/* sum = b1+b2 */
122 
123 /* chinese remainder theorem */
124 typedef struct CRTpre	CRTpre;		/* precomputed values for converting */
125 					/*  twixt residues and mpint */
126 typedef struct CRTres	CRTres;		/* residue form of an mpint */
127 
128 #pragma incomplete CRTpre
129 
130 struct CRTres
131 {
132 	int	n;		/* number of residues */
133 	mpint	*r[1];		/* residues */
134 };
135 
136 CRTpre*	crtpre(int, mpint**);			/* precompute conversion values */
137 CRTres*	crtin(CRTpre*, mpint*);			/* convert mpint to residues */
138 void	crtout(CRTpre*, CRTres*, mpint*);	/* convert residues to mpint */
139 void	crtprefree(CRTpre*);
140 void	crtresfree(CRTres*);
141 
142 
143 #pragma	varargck	type	"B"	mpint*
144