-rw-r--r-- 1384 libmceliece-20240726/crypto_kem/348864/avx/vec256.c raw
// 20240508 djb: include vec256_gf.h
// 20221230 djb: add linker line
// linker define vec256_sq vec256_inv
// linker use vec256_mul_asm
/*
This file is for functions related to 256-bit vectors
including functions for bitsliced field operations
*/
#include "vec256_gf.h"
/* bitsliced field squarings */
void vec256_sq(vec256 * out, vec256 * in)
{
int i;
vec256 result[GFBITS];
result[0] = in[0]^in[6];
result[1] = in[11];
result[2] = in[1]^in[7];
result[3] = in[6];
result[4] = in[2] ^ in[11] ^ in[8];
result[5] = in[7];
result[6] = in[3]^in[9];
result[7] = in[8];
result[8] = in[4]^in[10];
result[9] = in[9];
result[10] = in[5] ^ in[11];
result[11] = in[10];
for (i = 0; i < GFBITS; i++)
out[i] = result[i];
}
/* bitsliced field inverses */
void vec256_inv(vec256 * out, vec256 * in)
{
vec256 tmp_11[ GFBITS ];
vec256 tmp_1111[ GFBITS ];
vec256_copy(out, in);
vec256_sq(out, out);
vec256_mul(tmp_11, out, in); // ^11
vec256_sq(out, tmp_11);
vec256_sq(out, out);
vec256_mul(tmp_1111, out, tmp_11); // ^1111
vec256_sq(out, tmp_1111);
vec256_sq(out, out);
vec256_sq(out, out);
vec256_sq(out, out);
vec256_mul(out, out, tmp_1111); // ^11111111
vec256_sq(out, out);
vec256_sq(out, out);
vec256_mul(out, out, tmp_11); // ^1111111111
vec256_sq(out, out);
vec256_mul(out, out, in); // ^11111111111
vec256_sq(out, out); // ^111111111110
}