1 ------------------------------------------------------------------------------
2 ------------------------------------------------------------------------------
3 -- This file is part of 'Finite Field Arithmetic', aka 'FFA'. --
4 -- --
5 -- (C) 2019 Stanislav Datskovskiy ( www.loper-os.org ) --
6 -- http://wot.deedbot.org/17215D118B7239507FAFED98B98228A001ABFFC7.html --
7 -- --
8 -- You do not have, nor can you ever acquire the right to use, copy or --
9 -- distribute this software ; Should you use this software for any purpose, --
10 -- or copy and distribute it to anyone or in any manner, you are breaking --
11 -- the laws of whatever soi-disant jurisdiction, and you promise to --
12 -- continue doing so for the indefinite future. In any case, please --
13 -- always : read and understand any software ; verify any PGP signatures --
14 -- that you use - for any purpose. --
15 -- --
16 -- See also http://trilema.com/2015/a-new-software-licensing-paradigm . --
17 ------------------------------------------------------------------------------
18 ------------------------------------------------------------------------------
19
20 with FZ_Arith;
21 with FZ_Shift;
22 with FZ_Mul;
23 with FZ_Sqr;
24 with FZ_GCD;
25
26
27 -- Wrapper bodies for routines that we inline, but must enforce preconditions
28 -- on when called by FFA user.
29 package body FFA is
30
31 ----------------------------------------------------------------------------
32 --- FZ Basics
33 ----------------------------------------------------------------------------
34
35 -- Exchange X and Y
36 procedure FFA_FZ_Swap(X : in out FZ; Y : in out FZ) is
37 begin
38 FZ_Basic.FZ_Swap(X => X, Y => Y);
39 end FFA_FZ_Swap;
40
41 -- Constant-time MUX: Sel = 0: Result := X; Sel = 1: Result := Y
42 procedure FFA_FZ_Mux(X : in FZ; Y : in FZ;
43 Result : out FZ; Sel : in WBool) is
44 begin
45 FZ_Basic.FZ_Mux(X => X, Y => Y, Result => Result, Sel => Sel);
46 end FFA_FZ_Mux;
47
48 ----------------------------------------------------------------------------
49 --- Bitwise Operations on FZ
50 ----------------------------------------------------------------------------
51
52 -- Result := X & Y
53 procedure FFA_FZ_And(X : in FZ; Y : in FZ; Result : out FZ) is
54 begin
55 FZ_BitOp.FZ_And(X => X, Y => Y, Result => Result);
56 end FFA_FZ_And;
57
58 -- Result := X | Y
59 procedure FFA_FZ_Or(X : in FZ; Y : in FZ; Result : out FZ) is
60 begin
61 FZ_BitOp.FZ_Or(X => X, Y => Y, Result => Result);
62 end FFA_FZ_Or;
63
64 -- Result := X ^ Y
65 procedure FFA_FZ_Xor(X : in FZ; Y : in FZ; Result : out FZ) is
66 begin
67 FZ_BitOp.FZ_Xor(X => X, Y => Y, Result => Result);
68 end FFA_FZ_Xor;
69
70 -- NotN := ~N ('ones complement')
71 procedure FFA_FZ_Not(N : in FZ; NotN : out FZ) is
72 begin
73 FZ_BitOp.FZ_Not(N => N, NotN => NotN);
74 end FFA_FZ_Not;
75
76 ----------------------------------------------------------------------------
77 --- Arithmetic on FZ
78 ----------------------------------------------------------------------------
79
80 -- Sum := X + Y; Overflow := Carry
81 procedure FFA_FZ_Add(X : in FZ;
82 Y : in FZ;
83 Sum : out FZ;
84 Overflow : out WBool) is
85 begin
86 FZ_Arith.FZ_Add(X => X, Y => Y, Sum => Sum, Overflow => Overflow);
87 end FFA_FZ_Add;
88
89 -- Difference := X - Y; Underflow := Borrow
90 procedure FFA_FZ_Subtract(X : in FZ;
91 Y : in FZ;
92 Difference : out FZ;
93 Underflow : out WBool) is
94 begin
95 FZ_Arith.FZ_Sub(X => X, Y => Y, Difference => Difference,
96 Underflow => Underflow);
97 end FFA_FZ_Subtract;
98
99 ----------------------------------------------------------------------------
100 --- Multiplication on FZ
101 ----------------------------------------------------------------------------
102
103 procedure FFA_FZ_Multiply(X : in FZ;
104 Y : in FZ;
105 XY_Lo : out FZ;
106 XY_Hi : out FZ) is
107 begin
108 FZ_Mul.FZ_Multiply_Buffered(X => X, Y => Y,
109 XY_Lo => XY_Lo, XY_Hi => XY_Hi);
110 end FFA_FZ_Multiply;
111
112
113 -- Square. Preserves the inputs.
114 procedure FFA_FZ_Square(X : in FZ;
115 XX_Lo : out FZ;
116 XX_Hi : out FZ) is
117 begin
118 FZ_Sqr.FZ_Square_Buffered(X => X, XX_Lo => XX_Lo, XX_Hi => XX_Hi);
119 end FFA_FZ_Square;
120
121 ----------------------------------------------------------------------------
122 --- Other Operations on FZ
123 ----------------------------------------------------------------------------
124
125 -- Find Greatest Common Divisor (GCD) of X and Y.
126 procedure FFA_FZ_Greatest_Common_Divisor(X : in FZ;
127 Y : in FZ;
128 Result : out FZ) is
129 begin
130 FZ_GCD.FZ_Greatest_Common_Divisor(X => X, Y => Y, Result => Result);
131 end FFA_FZ_Greatest_Common_Divisor;
132
133 end FFA;