1 /*
2   This file is for loading/storing data in a little-endian fashion
3 */
4 
5 #include "util.h"
6 
7 #include "vec128.h"
8 
9 #include <stdint.h>
10 
11 void PQCLEAN_MCELIECE6688128F_AVX_store_i(unsigned char *out, uint64_t in, int i) {
12     int j;
13 
14     for (j = 0; j < i; j++) {
15         out[j] = (in >> (j * 8)) & 0xFF;
16     }
17 }
18 
19 void PQCLEAN_MCELIECE6688128F_AVX_store2(unsigned char *dest, uint16_t a) {
20     dest[0] = a & 0xFF;
21     dest[1] = a >> 8;
22 }
23 
24 uint16_t PQCLEAN_MCELIECE6688128F_AVX_load2(const unsigned char *src) {
25     uint16_t a;
26 
27     a = src[1];
28     a <<= 8;
29     a |= src[0];
30 
31     return a & GFMASK;
32 }
33 
34 uint32_t PQCLEAN_MCELIECE6688128F_AVX_load4(const unsigned char *src) {
35     uint32_t a;
36 
37     a  = src[3];
38     a <<= 8;
39     a |= src[2];
40     a <<= 8;
41     a |= src[1];
42     a <<= 8;
43     a |= src[0];
44 
45     return a;
46 }
47 
48 void PQCLEAN_MCELIECE6688128F_AVX_irr_load(vec128 *out, const unsigned char *in) {
49     int i, j;
50     uint64_t v[2];
51     uint16_t irr[ SYS_T + 1 ];
52 
53     for (i = 0; i < SYS_T; i++) {
54         irr[i] = PQCLEAN_MCELIECE6688128F_AVX_load2(in + i * 2);
55         irr[i] &= GFMASK;
56     }
57 
58     irr[ SYS_T ] = 1;
59 
60     for (i = 0; i < GFBITS; i++) {
61         v[0] = v[1] = 0;
62 
63         for (j =    63; j >=  0; j--) {
64             v[0] <<= 1;
65             v[0] |= (irr[j] >> i) & 1;
66         }
67         for (j = SYS_T; j >= 64; j--) {
68             v[1] <<= 1;
69             v[1] |= (irr[j] >> i) & 1;
70         }
71 
72         out[i] = PQCLEAN_MCELIECE6688128F_AVX_vec128_set2x(v[0], v[1]);
73     }
74 }
75 
76 void PQCLEAN_MCELIECE6688128F_AVX_store8(unsigned char *out, uint64_t in) {
77     out[0] = (in >> 0x00) & 0xFF;
78     out[1] = (in >> 0x08) & 0xFF;
79     out[2] = (in >> 0x10) & 0xFF;
80     out[3] = (in >> 0x18) & 0xFF;
81     out[4] = (in >> 0x20) & 0xFF;
82     out[5] = (in >> 0x28) & 0xFF;
83     out[6] = (in >> 0x30) & 0xFF;
84     out[7] = (in >> 0x38) & 0xFF;
85 }
86 
87 uint64_t PQCLEAN_MCELIECE6688128F_AVX_load8(const unsigned char *in) {
88     int i;
89     uint64_t ret = in[7];
90 
91     for (i = 6; i >= 0; i--) {
92         ret <<= 8;
93         ret |= in[i];
94     }
95 
96     return ret;
97 }
98 
99 vec128 PQCLEAN_MCELIECE6688128F_AVX_load16(const unsigned char *in) {
100     return PQCLEAN_MCELIECE6688128F_AVX_vec128_set2x( PQCLEAN_MCELIECE6688128F_AVX_load8(in), PQCLEAN_MCELIECE6688128F_AVX_load8(in + 8) );
101 }
102 
103 void PQCLEAN_MCELIECE6688128F_AVX_store16(unsigned char *out, vec128 in) {
104     PQCLEAN_MCELIECE6688128F_AVX_store8(out + 0, PQCLEAN_MCELIECE6688128F_AVX_vec128_extract(in, 0));
105     PQCLEAN_MCELIECE6688128F_AVX_store8(out + 8, PQCLEAN_MCELIECE6688128F_AVX_vec128_extract(in, 1));
106 }
107