1#include "fe.h"
2#include "crypto_int64.h"
3
4/*
5h = 2 * f * f
6Can overlap h with f.
7
8Preconditions:
9 |f| bounded by 1.65*2^26,1.65*2^25,1.65*2^26,1.65*2^25,etc.
10
11Postconditions:
12 |h| bounded by 1.01*2^25,1.01*2^24,1.01*2^25,1.01*2^24,etc.
13*/
14
15/*
16See fe_mul.c for discussion of implementation strategy.
17*/
18
19void fe_sq2(fe h,const fe f)
20{
21 crypto_int32 f0 = f[0];
22 crypto_int32 f1 = f[1];
23 crypto_int32 f2 = f[2];
24 crypto_int32 f3 = f[3];
25 crypto_int32 f4 = f[4];
26 crypto_int32 f5 = f[5];
27 crypto_int32 f6 = f[6];
28 crypto_int32 f7 = f[7];
29 crypto_int32 f8 = f[8];
30 crypto_int32 f9 = f[9];
31 crypto_int32 f0_2 = 2 * f0;
32 crypto_int32 f1_2 = 2 * f1;
33 crypto_int32 f2_2 = 2 * f2;
34 crypto_int32 f3_2 = 2 * f3;
35 crypto_int32 f4_2 = 2 * f4;
36 crypto_int32 f5_2 = 2 * f5;
37 crypto_int32 f6_2 = 2 * f6;
38 crypto_int32 f7_2 = 2 * f7;
39 crypto_int32 f5_38 = 38 * f5; /* 1.959375*2^30 */
40 crypto_int32 f6_19 = 19 * f6; /* 1.959375*2^30 */
41 crypto_int32 f7_38 = 38 * f7; /* 1.959375*2^30 */
42 crypto_int32 f8_19 = 19 * f8; /* 1.959375*2^30 */
43 crypto_int32 f9_38 = 38 * f9; /* 1.959375*2^30 */
44 crypto_int64 f0f0 = f0 * (crypto_int64) f0;
45 crypto_int64 f0f1_2 = f0_2 * (crypto_int64) f1;
46 crypto_int64 f0f2_2 = f0_2 * (crypto_int64) f2;
47 crypto_int64 f0f3_2 = f0_2 * (crypto_int64) f3;
48 crypto_int64 f0f4_2 = f0_2 * (crypto_int64) f4;
49 crypto_int64 f0f5_2 = f0_2 * (crypto_int64) f5;
50 crypto_int64 f0f6_2 = f0_2 * (crypto_int64) f6;
51 crypto_int64 f0f7_2 = f0_2 * (crypto_int64) f7;
52 crypto_int64 f0f8_2 = f0_2 * (crypto_int64) f8;
53 crypto_int64 f0f9_2 = f0_2 * (crypto_int64) f9;
54 crypto_int64 f1f1_2 = f1_2 * (crypto_int64) f1;
55 crypto_int64 f1f2_2 = f1_2 * (crypto_int64) f2;
56 crypto_int64 f1f3_4 = f1_2 * (crypto_int64) f3_2;
57 crypto_int64 f1f4_2 = f1_2 * (crypto_int64) f4;
58 crypto_int64 f1f5_4 = f1_2 * (crypto_int64) f5_2;
59 crypto_int64 f1f6_2 = f1_2 * (crypto_int64) f6;
60 crypto_int64 f1f7_4 = f1_2 * (crypto_int64) f7_2;
61 crypto_int64 f1f8_2 = f1_2 * (crypto_int64) f8;
62 crypto_int64 f1f9_76 = f1_2 * (crypto_int64) f9_38;
63 crypto_int64 f2f2 = f2 * (crypto_int64) f2;
64 crypto_int64 f2f3_2 = f2_2 * (crypto_int64) f3;
65 crypto_int64 f2f4_2 = f2_2 * (crypto_int64) f4;
66 crypto_int64 f2f5_2 = f2_2 * (crypto_int64) f5;
67 crypto_int64 f2f6_2 = f2_2 * (crypto_int64) f6;
68 crypto_int64 f2f7_2 = f2_2 * (crypto_int64) f7;
69 crypto_int64 f2f8_38 = f2_2 * (crypto_int64) f8_19;
70 crypto_int64 f2f9_38 = f2 * (crypto_int64) f9_38;
71 crypto_int64 f3f3_2 = f3_2 * (crypto_int64) f3;
72 crypto_int64 f3f4_2 = f3_2 * (crypto_int64) f4;
73 crypto_int64 f3f5_4 = f3_2 * (crypto_int64) f5_2;
74 crypto_int64 f3f6_2 = f3_2 * (crypto_int64) f6;
75 crypto_int64 f3f7_76 = f3_2 * (crypto_int64) f7_38;
76 crypto_int64 f3f8_38 = f3_2 * (crypto_int64) f8_19;
77 crypto_int64 f3f9_76 = f3_2 * (crypto_int64) f9_38;
78 crypto_int64 f4f4 = f4 * (crypto_int64) f4;
79 crypto_int64 f4f5_2 = f4_2 * (crypto_int64) f5;
80 crypto_int64 f4f6_38 = f4_2 * (crypto_int64) f6_19;
81 crypto_int64 f4f7_38 = f4 * (crypto_int64) f7_38;
82 crypto_int64 f4f8_38 = f4_2 * (crypto_int64) f8_19;
83 crypto_int64 f4f9_38 = f4 * (crypto_int64) f9_38;
84 crypto_int64 f5f5_38 = f5 * (crypto_int64) f5_38;
85 crypto_int64 f5f6_38 = f5_2 * (crypto_int64) f6_19;
86 crypto_int64 f5f7_76 = f5_2 * (crypto_int64) f7_38;
87 crypto_int64 f5f8_38 = f5_2 * (crypto_int64) f8_19;
88 crypto_int64 f5f9_76 = f5_2 * (crypto_int64) f9_38;
89 crypto_int64 f6f6_19 = f6 * (crypto_int64) f6_19;
90 crypto_int64 f6f7_38 = f6 * (crypto_int64) f7_38;
91 crypto_int64 f6f8_38 = f6_2 * (crypto_int64) f8_19;
92 crypto_int64 f6f9_38 = f6 * (crypto_int64) f9_38;
93 crypto_int64 f7f7_38 = f7 * (crypto_int64) f7_38;
94 crypto_int64 f7f8_38 = f7_2 * (crypto_int64) f8_19;
95 crypto_int64 f7f9_76 = f7_2 * (crypto_int64) f9_38;
96 crypto_int64 f8f8_19 = f8 * (crypto_int64) f8_19;
97 crypto_int64 f8f9_38 = f8 * (crypto_int64) f9_38;
98 crypto_int64 f9f9_38 = f9 * (crypto_int64) f9_38;
99 crypto_int64 h0 = f0f0 +f1f9_76+f2f8_38+f3f7_76+f4f6_38+f5f5_38;
100 crypto_int64 h1 = f0f1_2+f2f9_38+f3f8_38+f4f7_38+f5f6_38;
101 crypto_int64 h2 = f0f2_2+f1f1_2 +f3f9_76+f4f8_38+f5f7_76+f6f6_19;
102 crypto_int64 h3 = f0f3_2+f1f2_2 +f4f9_38+f5f8_38+f6f7_38;
103 crypto_int64 h4 = f0f4_2+f1f3_4 +f2f2 +f5f9_76+f6f8_38+f7f7_38;
104 crypto_int64 h5 = f0f5_2+f1f4_2 +f2f3_2 +f6f9_38+f7f8_38;
105 crypto_int64 h6 = f0f6_2+f1f5_4 +f2f4_2 +f3f3_2 +f7f9_76+f8f8_19;
106 crypto_int64 h7 = f0f7_2+f1f6_2 +f2f5_2 +f3f4_2 +f8f9_38;
107 crypto_int64 h8 = f0f8_2+f1f7_4 +f2f6_2 +f3f5_4 +f4f4 +f9f9_38;
108 crypto_int64 h9 = f0f9_2+f1f8_2 +f2f7_2 +f3f6_2 +f4f5_2;
109 crypto_int64 carry0;
110 crypto_int64 carry1;
111 crypto_int64 carry2;
112 crypto_int64 carry3;
113 crypto_int64 carry4;
114 crypto_int64 carry5;
115 crypto_int64 carry6;
116 crypto_int64 carry7;
117 crypto_int64 carry8;
118 crypto_int64 carry9;
119
120 h0 += h0;
121 h1 += h1;
122 h2 += h2;
123 h3 += h3;
124 h4 += h4;
125 h5 += h5;
126 h6 += h6;
127 h7 += h7;
128 h8 += h8;
129 h9 += h9;
130
131 carry0 = (h0 + (crypto_int64) (1<<25)) >> 26; h1 += carry0; h0 -= carry0 << 26;
132 carry4 = (h4 + (crypto_int64) (1<<25)) >> 26; h5 += carry4; h4 -= carry4 << 26;
133
134 carry1 = (h1 + (crypto_int64) (1<<24)) >> 25; h2 += carry1; h1 -= carry1 << 25;
135 carry5 = (h5 + (crypto_int64) (1<<24)) >> 25; h6 += carry5; h5 -= carry5 << 25;
136
137 carry2 = (h2 + (crypto_int64) (1<<25)) >> 26; h3 += carry2; h2 -= carry2 << 26;
138 carry6 = (h6 + (crypto_int64) (1<<25)) >> 26; h7 += carry6; h6 -= carry6 << 26;
139
140 carry3 = (h3 + (crypto_int64) (1<<24)) >> 25; h4 += carry3; h3 -= carry3 << 25;
141 carry7 = (h7 + (crypto_int64) (1<<24)) >> 25; h8 += carry7; h7 -= carry7 << 25;
142
143 carry4 = (h4 + (crypto_int64) (1<<25)) >> 26; h5 += carry4; h4 -= carry4 << 26;
144 carry8 = (h8 + (crypto_int64) (1<<25)) >> 26; h9 += carry8; h8 -= carry8 << 26;
145
146 carry9 = (h9 + (crypto_int64) (1<<24)) >> 25; h0 += carry9 * 19; h9 -= carry9 << 25;
147
148 carry0 = (h0 + (crypto_int64) (1<<25)) >> 26; h1 += carry0; h0 -= carry0 << 26;
149
150 h[0] = h0;
151 h[1] = h1;
152 h[2] = h2;
153 h[3] = h3;
154 h[4] = h4;
155 h[5] = h5;
156 h[6] = h6;
157 h[7] = h7;
158 h[8] = h8;
159 h[9] = h9;
160}
161