-rw-r--r-- 1123 libmceliece-20240726/crypto_kem/6688128/vec/gf.h raw
/*
This file is for functions for field arithmetic
*/
// 20221231 djb: const for GF_mul
#ifndef GF_H
#define GF_H
#define gf_add CRYPTO_NAMESPACE(gf_add)
#define gf_frac CRYPTO_NAMESPACE(gf_frac)
#define gf_inv CRYPTO_NAMESPACE(gf_inv)
#define gf_iszero CRYPTO_NAMESPACE(gf_iszero)
#define gf_mul2 CRYPTO_NAMESPACE(gf_mul2)
#define gf_mul CRYPTO_NAMESPACE(gf_mul)
#define GF_mul CRYPTO_NAMESPACE(GF_mul)
#include "params.h"
#include <stdint.h>
typedef uint16_t gf;
gf gf_iszero(gf);
gf gf_mul(gf, gf);
gf gf_frac(gf, gf);
gf gf_inv(gf);
void GF_mul(gf *, const gf *, const gf *);
/* 2 field multiplications */
static inline uint64_t gf_mul2(gf a, gf b0, gf b1)
{
int i;
uint64_t tmp=0;
uint64_t t0;
uint64_t t1;
uint64_t t;
uint64_t mask = 0x0000000100000001;
t0 = a;
t1 = b1;
t1 = (t1 << 32) | b0;
for (i = 0; i < GFBITS; i++)
{
tmp ^= t0 * (t1 & mask);
mask += mask;
}
//
t = tmp & 0x01FF000001FF0000;
tmp ^= (t >> 9) ^ (t >> 10) ^ (t >> 12) ^ (t >> 13);
t = tmp & 0x0000E0000000E000;
tmp ^= (t >> 9) ^ (t >> 10) ^ (t >> 12) ^ (t >> 13);
return tmp & 0x00001FFF00001FFF;
}
#endif