/* This file is for the inversion-free Berlekamp-Massey algorithm see https://ieeexplore.ieee.org/document/87857 */ #include "bm.h" #include "gf.h" extern gf PQCLEAN_MCELIECE6960119F_SSE_vec_reduce_asm(vec128 *); extern void PQCLEAN_MCELIECE6960119F_SSE_update_asm(vec128 *, gf); static inline uint16_t mask_nonzero(gf a) { uint32_t ret = a; ret -= 1; ret >>= 31; ret -= 1; return ret; } static inline uint16_t mask_leq(uint16_t a, uint16_t b) { uint32_t a_tmp = a; uint32_t b_tmp = b; uint32_t ret = b_tmp - a_tmp; ret >>= 31; ret -= 1; return ret; } static inline void vec128_cmov(vec128 *out, vec128 *in, uint16_t mask) { int i; vec128 v0, v1; vec128 m0 = PQCLEAN_MCELIECE6960119F_SSE_vec128_set1_16b( mask); vec128 m1 = PQCLEAN_MCELIECE6960119F_SSE_vec128_set1_16b(~mask); for (i = 0; i < GFBITS; i++) { v0 = PQCLEAN_MCELIECE6960119F_SSE_vec128_and(in[i], m0); v1 = PQCLEAN_MCELIECE6960119F_SSE_vec128_and(out[i], m1); out[i] = PQCLEAN_MCELIECE6960119F_SSE_vec128_or(v0, v1); } } static inline void interleave(vec128 *in, int idx0, int idx1, vec128 *mask, int b) { int s = 1 << b; vec128 x, y; x = PQCLEAN_MCELIECE6960119F_SSE_vec128_or(PQCLEAN_MCELIECE6960119F_SSE_vec128_and(in[idx0], mask[0]), PQCLEAN_MCELIECE6960119F_SSE_vec128_sll_2x(PQCLEAN_MCELIECE6960119F_SSE_vec128_and(in[idx1], mask[0]), s)); y = PQCLEAN_MCELIECE6960119F_SSE_vec128_or(PQCLEAN_MCELIECE6960119F_SSE_vec128_srl_2x(PQCLEAN_MCELIECE6960119F_SSE_vec128_and(in[idx0], mask[1]), s), PQCLEAN_MCELIECE6960119F_SSE_vec128_and(in[idx1], mask[1])); in[idx0] = x; in[idx1] = y; } /* input: in, field elements in bitsliced form */ /* output: out, field elements in non-bitsliced form */ static inline void get_coefs(gf *out, vec128 *in) { int i, k; vec128 mask[4][2]; vec128 buf[16]; for (i = 0; i < 13; i++) { buf[i] = in[i]; } for (i = 13; i < 16; i++) { buf[i] = PQCLEAN_MCELIECE6960119F_SSE_vec128_setzero(); } mask[0][0] = PQCLEAN_MCELIECE6960119F_SSE_vec128_set1_16b(0x5555); mask[0][1] = PQCLEAN_MCELIECE6960119F_SSE_vec128_set1_16b(0xAAAA); mask[1][0] = PQCLEAN_MCELIECE6960119F_SSE_vec128_set1_16b(0x3333); mask[1][1] = PQCLEAN_MCELIECE6960119F_SSE_vec128_set1_16b(0xCCCC); mask[2][0] = PQCLEAN_MCELIECE6960119F_SSE_vec128_set1_16b(0x0F0F); mask[2][1] = PQCLEAN_MCELIECE6960119F_SSE_vec128_set1_16b(0xF0F0); mask[3][0] = PQCLEAN_MCELIECE6960119F_SSE_vec128_set1_16b(0x00FF); mask[3][1] = PQCLEAN_MCELIECE6960119F_SSE_vec128_set1_16b(0xFF00); interleave(buf, 0, 8, mask[3], 3); interleave(buf, 1, 9, mask[3], 3); interleave(buf, 2, 10, mask[3], 3); interleave(buf, 3, 11, mask[3], 3); interleave(buf, 4, 12, mask[3], 3); interleave(buf, 5, 13, mask[3], 3); interleave(buf, 6, 14, mask[3], 3); interleave(buf, 7, 15, mask[3], 3); interleave(buf, 0, 4, mask[2], 2); interleave(buf, 1, 5, mask[2], 2); interleave(buf, 2, 6, mask[2], 2); interleave(buf, 3, 7, mask[2], 2); interleave(buf, 8, 12, mask[2], 2); interleave(buf, 9, 13, mask[2], 2); interleave(buf, 10, 14, mask[2], 2); interleave(buf, 11, 15, mask[2], 2); interleave(buf, 0, 2, mask[1], 1); interleave(buf, 1, 3, mask[1], 1); interleave(buf, 4, 6, mask[1], 1); interleave(buf, 5, 7, mask[1], 1); interleave(buf, 8, 10, mask[1], 1); interleave(buf, 9, 11, mask[1], 1); interleave(buf, 12, 14, mask[1], 1); interleave(buf, 13, 15, mask[1], 1); interleave(buf, 0, 1, mask[0], 0); interleave(buf, 2, 3, mask[0], 0); interleave(buf, 4, 5, mask[0], 0); interleave(buf, 6, 7, mask[0], 0); interleave(buf, 8, 9, mask[0], 0); interleave(buf, 10, 11, mask[0], 0); interleave(buf, 12, 13, mask[0], 0); interleave(buf, 14, 15, mask[0], 0); for (i = 0; i < 16; i++) { for (k = 0; k < 4; k++) { out[ (4 * 0 + k) * 16 + i ] = (PQCLEAN_MCELIECE6960119F_SSE_vec128_extract(buf[i], 0) >> (k * 16)) & GFMASK; out[ (4 * 1 + k) * 16 + i ] = (PQCLEAN_MCELIECE6960119F_SSE_vec128_extract(buf[i], 1) >> (k * 16)) & GFMASK; } } } /* input: in, sequence of field elements */ /* output: out, minimal polynomial of in */ void PQCLEAN_MCELIECE6960119F_SSE_bm(vec128 *out, vec128 in[][ GFBITS ]) { int i; uint16_t N, L; uint16_t mask; uint64_t one = 1; uint64_t v[2]; vec128 prod[ GFBITS ]; vec128 interval[GFBITS]; vec128 dd[ GFBITS ], bb[ GFBITS ]; vec128 B[ GFBITS ], C[ GFBITS ]; vec128 B_tmp[ GFBITS ], C_tmp[ GFBITS ]; gf d, b; gf coefs[256]; // initialization get_coefs(&coefs[ 0], in[0]); get_coefs(&coefs[128], in[1]); C[0] = PQCLEAN_MCELIECE6960119F_SSE_vec128_set2x(0, one << 63); B[0] = PQCLEAN_MCELIECE6960119F_SSE_vec128_set2x(0, one << 62); for (i = 1; i < GFBITS; i++) { C[i] = B[i] = PQCLEAN_MCELIECE6960119F_SSE_vec128_setzero(); } b = 1; L = 0; // for (i = 0; i < GFBITS; i++) { interval[i] = PQCLEAN_MCELIECE6960119F_SSE_vec128_setzero(); } for (N = 0; N < SYS_T * 2; N++) { PQCLEAN_MCELIECE6960119F_SSE_update_asm(interval, coefs[N]); PQCLEAN_MCELIECE6960119F_SSE_vec128_mul(prod, C, (vec128 *) interval); d = PQCLEAN_MCELIECE6960119F_SSE_vec_reduce_asm(prod); mask = mask_nonzero(d) & mask_leq(L * 2, N); for (i = 0; i < GFBITS; i++) { dd[i] = PQCLEAN_MCELIECE6960119F_SSE_vec128_setbits((d >> i) & 1); bb[i] = PQCLEAN_MCELIECE6960119F_SSE_vec128_setbits((b >> i) & 1); } PQCLEAN_MCELIECE6960119F_SSE_vec128_mul(B_tmp, dd, B); PQCLEAN_MCELIECE6960119F_SSE_vec128_mul(C_tmp, bb, C); vec128_cmov(B, C, mask); PQCLEAN_MCELIECE6960119F_SSE_update_asm(B, 0); for (i = 0; i < GFBITS; i++) { C[i] = PQCLEAN_MCELIECE6960119F_SSE_vec128_xor(B_tmp[i], C_tmp[i]); } b = (d & mask) | (b & ~mask); L = ((N + 1 - L) & mask) | (L & ~mask); } for (i = 0; i < GFBITS; i++) { v[0] = PQCLEAN_MCELIECE6960119F_SSE_vec128_extract(C[i], 0); v[1] = PQCLEAN_MCELIECE6960119F_SSE_vec128_extract(C[i], 1); out[i] = PQCLEAN_MCELIECE6960119F_SSE_vec128_set2x((v[0] >> 8) | (v[1] << 56), v[1] >> 8); } }