gf_w4.c 50.9 KB
``````/*
* GF-Complete: A Comprehensive Open Source Library for Galois Field Arithmetic
* James S. Plank, Ethan L. Miller, Kevin M. Greenan,
* Benjamin A. Arnold, John A. Burnum, Adam W. Disney, Allen C. McBride.
*
* gf_w4.c
*
* Routines for 4-bit Galois fields
*/

#include "gf_int.h"
#include <stdio.h>
#include <stdlib.h>
#include "gf_w4.h"

#define AB2(ip, am1 ,am2, b, t1, t2) {\
t1 = (b << 1) & am1;\
t2 = b & am2; \
t2 = ((t2 << 1) - (t2 >> (GF_FIELD_WIDTH-1))); \
b = (t1 ^ (t2 & ip));}

// ToDo(KMG/JSP): Why is 0x88 hard-coded?
#define SSE_AB2(pp, m1, va, t1, t2) {\
t1 = _mm_and_si128(_mm_slli_epi64(va, 1), m1); \
t2 = _mm_and_si128(va, _mm_set1_epi8(0x88)); \
t2 = _mm_sub_epi64 (_mm_slli_epi64(t2, 1), _mm_srli_epi64(t2, (GF_FIELD_WIDTH-1))); \
va = _mm_xor_si128(t1, _mm_and_si128(t2, pp)); }

/* ------------------------------------------------------------
JSP: These are basic and work from multiple implementations.
*/

static
inline
gf_val_32_t gf_w4_inverse_from_divide (gf_t *gf, gf_val_32_t a)
{
return gf->divide.w32(gf, 1, a);
}

static
inline
gf_val_32_t gf_w4_divide_from_inverse (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{
b = gf->inverse.w32(gf, b);
return gf->multiply.w32(gf, a, b);
}

static
inline
gf_val_32_t gf_w4_euclid (gf_t *gf, gf_val_32_t b)
{
gf_val_32_t e_i, e_im1, e_ip1;
gf_val_32_t d_i, d_im1, d_ip1;
gf_val_32_t y_i, y_im1, y_ip1;
gf_val_32_t c_i;

if (b == 0) return -1;
e_im1 = ((gf_internal_t *) (gf->scratch))->prim_poly;
e_i = b;
d_im1 = 4;
for (d_i = d_im1; ((1 << d_i) & e_i) == 0; d_i--) ;
y_i = 1;
y_im1 = 0;

while (e_i != 1) {
e_ip1 = e_im1;
d_ip1 = d_im1;
c_i = 0;

while (d_ip1 >= d_i) {
c_i ^= (1 << (d_ip1 - d_i));
e_ip1 ^= (e_i << (d_ip1 - d_i));
if (e_ip1 == 0) return 0;
while ((e_ip1 & (1 << d_ip1)) == 0) d_ip1--;
}

y_ip1 = y_im1 ^ gf->multiply.w32(gf, c_i, y_i);
y_im1 = y_i;
y_i = y_ip1;

e_im1 = e_i;
d_im1 = d_i;
e_i = e_ip1;
d_i = d_ip1;
}

return y_i;
}

static
gf_val_32_t gf_w4_extract_word(gf_t *gf, void *start, int bytes, int index)
{
uint8_t *r8, v;

r8 = (uint8_t *) start;
v = r8[index/2];
if (index%2) {
return v >> 4;
} else {
return v&0xf;
}
}

static
inline
gf_val_32_t gf_w4_matrix (gf_t *gf, gf_val_32_t b)
{
return gf_bitmatrix_inverse(b, 4, ((gf_internal_t *) (gf->scratch))->prim_poly);
}

static
inline
gf_val_32_t
gf_w4_shift_multiply (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{
uint8_t product, i, pp;
gf_internal_t *h;

h = (gf_internal_t *) gf->scratch;
pp = h->prim_poly;

product = 0;

for (i = 0; i < GF_FIELD_WIDTH; i++) {
if (a & (1 << i)) product ^= (b << i);
}
for (i = (GF_FIELD_WIDTH*2-2); i >= GF_FIELD_WIDTH; i--) {
if (product & (1 << i)) product ^= (pp << (i-GF_FIELD_WIDTH));
}
return product;
}

/* Ben: This function works, but it is 33% slower than the normal shift mult */

static
inline
gf_val_32_t
gf_w4_clm_multiply (gf_t *gf, gf_val_32_t a4, gf_val_32_t b4)
{
gf_val_32_t rv = 0;

#if defined(INTEL_SSE4_PCLMUL)

__m128i         a, b;
__m128i         result;
__m128i         prim_poly;
__m128i         w;
gf_internal_t * h = gf->scratch;

a = _mm_insert_epi32 (_mm_setzero_si128(), a4, 0);
b = _mm_insert_epi32 (a, b4, 0);

prim_poly = _mm_set_epi32(0, 0, 0, (uint32_t)(h->prim_poly & 0x1fULL));

/* Do the initial multiply */

result = _mm_clmulepi64_si128 (a, b, 0);

/* Ben/JSP: Do prim_poly reduction once. We are guaranteed that we will only
have to do the reduction only once, because (w-2)/z == 1. Where
z is equal to the number of zeros after the leading 1.

_mm_clmulepi64_si128 is the carryless multiply operation. Here
_mm_srli_epi64 shifts the result to the right by 4 bits. This allows
us to multiply the prim_poly by the leading bits of the result. We
then xor the result of that operation back with the result. */

w = _mm_clmulepi64_si128 (prim_poly, _mm_srli_epi64 (result, 4), 0);
result = _mm_xor_si128 (result, w);

/* Extracts 32 bit value from result. */

rv = ((gf_val_32_t)_mm_extract_epi32(result, 0));
#endif
return rv;
}

static
void
gf_w4_multiply_region_from_single(gf_t *gf, void *src, void *dest, gf_val_32_t val, int bytes, int
xor)
{
gf_region_data rd;
uint8_t *s8;
uint8_t *d8;

if (val == 0) { gf_multby_zero(dest, bytes, xor); return; }
if (val == 1) { gf_multby_one(src, dest, bytes, xor); return; }

gf_set_region_data(&rd, gf, src, dest, bytes, val, xor, 1);
gf_do_initial_region_alignment(&rd);

s8 = (uint8_t *) rd.s_start;
d8 = (uint8_t *) rd.d_start;

if (xor) {
while (d8 < ((uint8_t *) rd.d_top)) {
*d8 ^= (gf->multiply.w32(gf, val, (*s8 & 0xf)) |
((gf->multiply.w32(gf, val, (*s8 >> 4))) << 4));
d8++;
s8++;
}
} else {
while (d8 < ((uint8_t *) rd.d_top)) {
*d8 = (gf->multiply.w32(gf, val, (*s8 & 0xf)) |
((gf->multiply.w32(gf, val, (*s8 >> 4))) << 4));
d8++;
s8++;
}
}
gf_do_final_region_alignment(&rd);
}

/* ------------------------------------------------------------
IMPLEMENTATION: LOG_TABLE:

JSP: This is a basic log-antilog implementation.
I'm not going to spend any time optimizing it because the
other techniques are faster for both single and region
operations.
*/

static
inline
gf_val_32_t
gf_w4_log_multiply (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{
struct gf_logtable_data *ltd;

ltd = (struct gf_logtable_data *) ((gf_internal_t *) (gf->scratch))->private;
return (a == 0 || b == 0) ? 0 : ltd->antilog_tbl[(unsigned)(ltd->log_tbl[a] + ltd->log_tbl[b])];
}

static
inline
gf_val_32_t
gf_w4_log_divide (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{
int log_sum = 0;
struct gf_logtable_data *ltd;

if (a == 0 || b == 0) return 0;
ltd = (struct gf_logtable_data *) ((gf_internal_t *) (gf->scratch))->private;

log_sum = ltd->log_tbl[a] - ltd->log_tbl[b];
return (ltd->antilog_tbl_div[log_sum]);
}

static
void
gf_w4_log_multiply_region(gf_t *gf, void *src, void *dest, gf_val_32_t val, int bytes, int xor)
{
int i;
uint8_t lv, b, c;
uint8_t *s8, *d8;

struct gf_logtable_data *ltd;

if (val == 0) { gf_multby_zero(dest, bytes, xor); return; }
if (val == 1) { gf_multby_one(src, dest, bytes, xor); return; }

ltd = (struct gf_logtable_data *) ((gf_internal_t *) (gf->scratch))->private;
s8 = (uint8_t *) src;
d8 = (uint8_t *) dest;

lv = ltd->log_tbl[val];

for (i = 0; i < bytes; i++) {
c = (xor) ? d8[i] : 0;
b = (s8[i] >> GF_FIELD_WIDTH);
c ^= (b == 0) ? 0 : (ltd->antilog_tbl[lv + ltd->log_tbl[b]] << GF_FIELD_WIDTH);
b = (s8[i] & 0xf);
c ^= (b == 0) ? 0 : ltd->antilog_tbl[lv + ltd->log_tbl[b]];
d8[i] = c;
}
}

static
int gf_w4_log_init(gf_t *gf)
{
gf_internal_t *h;
struct gf_logtable_data *ltd;
int i, b;

h = (gf_internal_t *) gf->scratch;
ltd = h->private;

for (i = 0; i < GF_FIELD_SIZE; i++)
ltd->log_tbl[i]=0;

ltd->antilog_tbl_div = ltd->antilog_tbl + (GF_FIELD_SIZE-1);
b = 1;
i = 0;
do {
if (ltd->log_tbl[b] != 0 && i != 0) {
fprintf(stderr, "Cannot construct log table: Polynomial is not primitive.\n\n");
return 0;
}
ltd->log_tbl[b] = i;
ltd->antilog_tbl[i] = b;
ltd->antilog_tbl[i+GF_FIELD_SIZE-1] = b;
b <<= 1;
i++;
if (b & GF_FIELD_SIZE) b = b ^ h->prim_poly;
} while (b != 1);

if (i != GF_FIELD_SIZE - 1) {
_gf_errno = GF_E_LOGPOLY;
return 0;
}

gf->inverse.w32 = gf_w4_inverse_from_divide;
gf->divide.w32 = gf_w4_log_divide;
gf->multiply.w32 = gf_w4_log_multiply;
gf->multiply_region.w32 = gf_w4_log_multiply_region;
return 1;
}

/* ------------------------------------------------------------
IMPLEMENTATION: SINGLE TABLE: JSP.
*/

static
inline
gf_val_32_t
gf_w4_single_table_multiply (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{
struct gf_single_table_data *std;

std = (struct gf_single_table_data *) ((gf_internal_t *) (gf->scratch))->private;
return std->mult[a][b];
}

static
inline
gf_val_32_t
gf_w4_single_table_divide (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{
struct gf_single_table_data *std;

std = (struct gf_single_table_data *) ((gf_internal_t *) (gf->scratch))->private;
return std->div[a][b];
}

static
void
gf_w4_single_table_multiply_region(gf_t *gf, void *src, void *dest, gf_val_32_t val, int bytes, int xor)
{
int i;
uint8_t b, c;
uint8_t *s8, *d8;

struct gf_single_table_data *std;

if (val == 0) { gf_multby_zero(dest, bytes, xor); return; }
if (val == 1) { gf_multby_one(src, dest, bytes, xor); return; }

std = (struct gf_single_table_data *) ((gf_internal_t *) (gf->scratch))->private;
s8 = (uint8_t *) src;
d8 = (uint8_t *) dest;

for (i = 0; i < bytes; i++) {
c = (xor) ? d8[i] : 0;
b = (s8[i] >> GF_FIELD_WIDTH);
c ^= (std->mult[val][b] << GF_FIELD_WIDTH);
b = (s8[i] & 0xf);
c ^= (std->mult[val][b]);
d8[i] = c;
}
}

#define MM_PRINT(s, r) { uint8_t blah[16]; printf("%-12s", s); _mm_storeu_si128((__m128i *)blah, r); for (i = 0; i < 16; i++) printf(" %02x", blah[i]); printf("\n"); }

#ifdef INTEL_SSSE3
static
void
gf_w4_single_table_sse_multiply_region(gf_t *gf, void *src, void *dest, gf_val_32_t val, int bytes, int xor)
{
gf_region_data rd;
uint8_t *base, *sptr, *dptr, *top;
__m128i  tl, loset, r, va, th;

struct gf_single_table_data *std;

if (val == 0) { gf_multby_zero(dest, bytes, xor); return; }
if (val == 1) { gf_multby_one(src, dest, bytes, xor); return; }

gf_set_region_data(&rd, gf, src, dest, bytes, val, xor, 16);

std = (struct gf_single_table_data *) ((gf_internal_t *) (gf->scratch))->private;
base = (uint8_t *) std->mult;
base += (val << GF_FIELD_WIDTH);

gf_do_initial_region_alignment(&rd);

th = _mm_slli_epi64(tl, 4);
loset = _mm_set1_epi8 (0x0f);

sptr = rd.s_start;
dptr = rd.d_start;
top = rd.s_top;

while (sptr < (uint8_t *) top) {
r = _mm_and_si128 (loset, va);
r = _mm_shuffle_epi8 (tl, r);
va = _mm_srli_epi64 (va, 4);
va = _mm_and_si128 (loset, va);
va = _mm_shuffle_epi8 (th, va);
r = _mm_xor_si128 (r, va);
va = (xor) ? _mm_load_si128 ((__m128i *)(dptr)) : _mm_setzero_si128();
r = _mm_xor_si128 (r, va);
_mm_store_si128 ((__m128i *)(dptr), r);
dptr += 16;
sptr += 16;
}
gf_do_final_region_alignment(&rd);

}
#endif

static
int gf_w4_single_table_init(gf_t *gf)
{
gf_internal_t *h;
struct gf_single_table_data *std;
int a, b, prod;

h = (gf_internal_t *) gf->scratch;
std = (struct gf_single_table_data *)h->private;

bzero(std->mult, sizeof(uint8_t) * GF_FIELD_SIZE * GF_FIELD_SIZE);
bzero(std->div, sizeof(uint8_t) * GF_FIELD_SIZE * GF_FIELD_SIZE);

for (a = 1; a < GF_FIELD_SIZE; a++) {
for (b = 1; b < GF_FIELD_SIZE; b++) {
prod = gf_w4_shift_multiply(gf, a, b);
std->mult[a][b] = prod;
std->div[prod][b] = a;
}
}

gf->inverse.w32 = NULL;
gf->divide.w32 = gf_w4_single_table_divide;
gf->multiply.w32 = gf_w4_single_table_multiply;
#if defined(INTEL_SSSE3) || defined(ARM_NEON)
if(h->region_type & (GF_REGION_NOSIMD | GF_REGION_CAUCHY))
gf->multiply_region.w32 = gf_w4_single_table_multiply_region;
else
#if defined(INTEL_SSSE3)
gf->multiply_region.w32 = gf_w4_single_table_sse_multiply_region;
#elif defined(ARM_NEON)
gf_w4_neon_single_table_init(gf);
#endif
#else
gf->multiply_region.w32 = gf_w4_single_table_multiply_region;
if (h->region_type & GF_REGION_SIMD) return 0;
#endif

return 1;
}

/* ------------------------------------------------------------
IMPLEMENTATION: DOUBLE TABLE: JSP.
*/

static
inline
gf_val_32_t
gf_w4_double_table_multiply (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{
struct gf_double_table_data *std;

std = (struct gf_double_table_data *) ((gf_internal_t *) (gf->scratch))->private;
return std->mult[a][b];
}

static
inline
gf_val_32_t
gf_w4_double_table_divide (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{
struct gf_double_table_data *std;

std = (struct gf_double_table_data *) ((gf_internal_t *) (gf->scratch))->private;
return std->div[a][b];
}

static
void
gf_w4_double_table_multiply_region(gf_t *gf, void *src, void *dest, gf_val_32_t val, int bytes, int xor)
{
int i;
uint8_t *s8, *d8, *base;
gf_region_data rd;
struct gf_double_table_data *std;

if (val == 0) { gf_multby_zero(dest, bytes, xor); return; }
if (val == 1) { gf_multby_one(src, dest, bytes, xor); return; }

gf_set_region_data(&rd, gf, src, dest, bytes, val, xor, 8);

std = (struct gf_double_table_data *) ((gf_internal_t *) (gf->scratch))->private;
s8 = (uint8_t *) src;
d8 = (uint8_t *) dest;
base = (uint8_t *) std->mult;
base += (val << GF_DOUBLE_WIDTH);

if (xor) {
for (i = 0; i < bytes; i++) d8[i] ^= base[s8[i]];
} else {
for (i = 0; i < bytes; i++) d8[i] = base[s8[i]];
}
}

static
int gf_w4_double_table_init(gf_t *gf)
{
gf_internal_t *h;
struct gf_double_table_data *std;
int a, b, c, prod, ab;
uint8_t mult[GF_FIELD_SIZE][GF_FIELD_SIZE];

h = (gf_internal_t *) gf->scratch;
std = (struct gf_double_table_data *)h->private;

bzero(mult, sizeof(uint8_t) * GF_FIELD_SIZE * GF_FIELD_SIZE);
bzero(std->div, sizeof(uint8_t) * GF_FIELD_SIZE * GF_FIELD_SIZE);

for (a = 1; a < GF_FIELD_SIZE; a++) {
for (b = 1; b < GF_FIELD_SIZE; b++) {
prod = gf_w4_shift_multiply(gf, a, b);
mult[a][b] = prod;
std->div[prod][b] = a;
}
}
bzero(std->mult, sizeof(uint8_t) * GF_FIELD_SIZE * GF_FIELD_SIZE * GF_FIELD_SIZE);
for (a = 0; a < GF_FIELD_SIZE; a++) {
for (b = 0; b < GF_FIELD_SIZE; b++) {
ab = mult[a][b];
for (c = 0; c < GF_FIELD_SIZE; c++) {
std->mult[a][(b << 4) | c] = ((ab << 4) | mult[a][c]);
}
}
}

gf->inverse.w32 = NULL;
gf->divide.w32 = gf_w4_double_table_divide;
gf->multiply.w32 = gf_w4_double_table_multiply;
gf->multiply_region.w32 = gf_w4_double_table_multiply_region;
return 1;
}

static
inline
gf_val_32_t
gf_w4_quad_table_lazy_divide (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{

std = (struct gf_quad_table_lazy_data *) ((gf_internal_t *) (gf->scratch))->private;
return std->div[a][b];
}

static
inline
gf_val_32_t
gf_w4_quad_table_lazy_multiply (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{

std = (struct gf_quad_table_lazy_data *) ((gf_internal_t *) (gf->scratch))->private;
return std->smult[a][b];
}

static
inline
gf_val_32_t
gf_w4_quad_table_divide (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{

std = (struct gf_quad_table_data *) ((gf_internal_t *) (gf->scratch))->private;
return std->div[a][b];
}

static
inline
gf_val_32_t
gf_w4_quad_table_multiply (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{
uint16_t v;

std = (struct gf_quad_table_data *) ((gf_internal_t *) (gf->scratch))->private;
v = std->mult[a][b];
return v;
}

static
void
gf_w4_quad_table_multiply_region(gf_t *gf, void *src, void *dest, gf_val_32_t val, int bytes, int xor)
{
uint16_t *base;
gf_region_data rd;
gf_internal_t *h;
int a, b, c, d, va, vb, vc, vd;

if (val == 0) { gf_multby_zero(dest, bytes, xor); return; }
if (val == 1) { gf_multby_one(src, dest, bytes, xor); return; }

h = (gf_internal_t *) (gf->scratch);
if (h->region_type & GF_REGION_LAZY) {
ltd = (struct gf_quad_table_lazy_data *) ((gf_internal_t *) (gf->scratch))->private;
base = ltd->mult;
for (a = 0; a < 16; a++) {
va = (ltd->smult[val][a] << 12);
for (b = 0; b < 16; b++) {
vb = (ltd->smult[val][b] << 8);
for (c = 0; c < 16; c++) {
vc = (ltd->smult[val][c] << 4);
for (d = 0; d < 16; d++) {
vd = ltd->smult[val][d];
base[(a << 12) | (b << 8) | (c << 4) | d ] = (va | vb | vc | vd);
}
}
}
}
} else {
std = (struct gf_quad_table_data *) ((gf_internal_t *) (gf->scratch))->private;
base = &(std->mult[val][0]);
}

gf_set_region_data(&rd, gf, src, dest, bytes, val, xor, 8);
gf_do_initial_region_alignment(&rd);
gf_two_byte_region_table_multiply(&rd, base);
gf_do_final_region_alignment(&rd);
}

static
{
gf_internal_t *h;
int prod, val, a, b, c, d, va, vb, vc, vd;
uint8_t mult[GF_FIELD_SIZE][GF_FIELD_SIZE];

h = (gf_internal_t *) gf->scratch;

bzero(mult, sizeof(uint8_t) * GF_FIELD_SIZE * GF_FIELD_SIZE);
bzero(std->div, sizeof(uint8_t) * GF_FIELD_SIZE * GF_FIELD_SIZE);

for (a = 1; a < GF_FIELD_SIZE; a++) {
for (b = 1; b < GF_FIELD_SIZE; b++) {
prod = gf_w4_shift_multiply(gf, a, b);
mult[a][b] = prod;
std->div[prod][b] = a;
}
}

for (val = 0; val < 16; val++) {
for (a = 0; a < 16; a++) {
va = (mult[val][a] << 12);
for (b = 0; b < 16; b++) {
vb = (mult[val][b] << 8);
for (c = 0; c < 16; c++) {
vc = (mult[val][c] << 4);
for (d = 0; d < 16; d++) {
vd = mult[val][d];
std->mult[val][(a << 12) | (b << 8) | (c << 4) | d ] = (va | vb | vc | vd);
}
}
}
}
}

gf->inverse.w32 = NULL;
return 1;
}
static
{
gf_internal_t *h;
int a, b, prod, loga, logb;
uint8_t log_tbl[GF_FIELD_SIZE];
uint8_t antilog_tbl[GF_FIELD_SIZE*2];

h = (gf_internal_t *) gf->scratch;

b = 1;
for (a = 0; a < GF_MULT_GROUP_SIZE; a++) {
log_tbl[b] = a;
antilog_tbl[a] = b;
antilog_tbl[a+GF_MULT_GROUP_SIZE] = b;
b <<= 1;
if (b & GF_FIELD_SIZE) {
b = b ^ h->prim_poly;
}
}

bzero(std->smult, sizeof(uint8_t) * GF_FIELD_SIZE * GF_FIELD_SIZE);
bzero(std->div, sizeof(uint8_t) * GF_FIELD_SIZE * GF_FIELD_SIZE);

for (a = 1; a < GF_FIELD_SIZE; a++) {
loga = log_tbl[a];
for (b = 1; b < GF_FIELD_SIZE; b++) {
logb = log_tbl[b];
prod = antilog_tbl[loga+logb];
std->smult[a][b] = prod;
std->div[prod][b] = a;
}
}

gf->inverse.w32 = NULL;
return 1;
}

static
int gf_w4_table_init(gf_t *gf)
{
int rt;
gf_internal_t *h;
int simd = 0;

#if defined(INTEL_SSSE3) || defined(ARM_NEON)
simd = 1;
#endif

h = (gf_internal_t *) gf->scratch;
rt = (h->region_type);

if (h->mult_type == GF_MULT_DEFAULT && !simd) rt |= GF_REGION_DOUBLE_TABLE;

if (rt & GF_REGION_DOUBLE_TABLE) {
return gf_w4_double_table_init(gf);
} else if (rt & GF_REGION_QUAD_TABLE) {
if (rt & GF_REGION_LAZY) {
} else {
}
} else {
return gf_w4_single_table_init(gf);
}
return 0;
}

/* ------------------------------------------------------------
JSP: GF_MULT_BYTWO_p and _b: See the paper.
*/

static
inline
gf_val_32_t
gf_w4_bytwo_p_multiply (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{
gf_internal_t *h;

h = (gf_internal_t *) gf->scratch;
pp = h->prim_poly;

prod = 0;

prod = ((prod << 1) ^ pp);
} else {
prod <<= 1;
}
if (a & amask) prod ^= b;
}
return prod;
}

static
inline
gf_val_32_t
gf_w4_bytwo_b_multiply (gf_t *gf, gf_val_32_t a, gf_val_32_t b)
{
gf_internal_t *h;

h = (gf_internal_t *) gf->scratch;
pp = h->prim_poly;

prod = 0;

while (1) {
if (a & 1) prod ^= b;
a >>= 1;
if (a == 0) return prod;
b = ((b << 1) ^ pp);
} else {
b <<= 1;
}
}
}

static
void
gf_w4_bytwo_p_nosse_multiply_region(gf_t *gf, void *src, void *dest, gf_val_32_t val, int bytes, int xor)
{
uint64_t *s64, *d64, t1, t2, ta, prod, amask;
gf_region_data rd;
struct gf_bytwo_data *btd;

if (val == 0) { gf_multby_zero(dest, bytes, xor); return; }
if (val == 1) { gf_multby_one(src, dest, bytes, xor); return; }

btd = (struct gf_bytwo_data *) ((gf_internal_t *) (gf->scratch))->private;

gf_set_region_data(&rd, gf, src, dest, bytes, val, xor, 8);
gf_do_initial_region_alignment(&rd);

s64 = (uint64_t *) rd.s_start;
d64 = (uint64_t *) rd.d_start;

if (xor) {
while (s64 < (uint64_t *) rd.s_top) {
prod = 0;
ta = *s64;
if (val & amask) prod ^= ta;
}
*d64 ^= prod;
d64++;
s64++;
}
} else {
while (s64 < (uint64_t *) rd.s_top) {
prod = 0;
ta = *s64;
if (val & amask) prod ^= ta;
}
*d64 = prod;
d64++;
s64++;
}
}
gf_do_final_region_alignment(&rd);
}

#define BYTWO_P_ONESTEP {\
SSE_AB2(pp, m1, prod, t1, t2); \
t1 = _mm_and_si128(v, one); \
t1 = _mm_sub_epi8(t1, one); \
t1 = _mm_and_si128(t1, ta); \
prod = _mm_xor_si128(prod, t1); \
v = _mm_srli_epi64(v, 1); }

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_p_sse_multiply_region(gf_t *gf, void *src, void *dest, gf_val_32_t val, int bytes, int xor)
{
int i;
uint8_t *s8, *d8;
uint8_t vrev;
__m128i pp, m1, ta, prod, t1, t2, tp, one, v;
struct gf_bytwo_data *btd;
gf_region_data rd;

if (val == 0) { gf_multby_zero(dest, bytes, xor); return; }
if (val == 1) { gf_multby_one(src, dest, bytes, xor); return; }

btd = (struct gf_bytwo_data *) ((gf_internal_t *) (gf->scratch))->private;

gf_set_region_data(&rd, gf, src, dest, bytes, val, xor, 16);
gf_do_initial_region_alignment(&rd);

vrev = 0;
for (i = 0; i < 4; i++) {
vrev <<= 1;
if (!(val & (1 << i))) vrev |= 1;
}

s8 = (uint8_t *) rd.s_start;
d8 = (uint8_t *) rd.d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);
one = _mm_set1_epi8(1);

while (d8 < (uint8_t *) rd.d_top) {
prod = _mm_setzero_si128();
v = _mm_set1_epi8(vrev);
tp = (!xor) ? _mm_setzero_si128() : _mm_load_si128((__m128i *) d8);
BYTWO_P_ONESTEP;
BYTWO_P_ONESTEP;
BYTWO_P_ONESTEP;
BYTWO_P_ONESTEP;
_mm_store_si128((__m128i *) d8, _mm_xor_si128(prod, tp));
d8 += 16;
s8 += 16;
}
gf_do_final_region_alignment(&rd);
}
#endif

/*
static
void
gf_w4_bytwo_b_sse_multiply_region(gf_t *gf, void *src, void *dest, gf_val_32_t val, int bytes, int xor)
{
#ifdef INTEL_SSE2
uint8_t *d8, *s8, tb;
__m128i pp, m1, m2, t1, t2, va, vb;
struct gf_bytwo_data *btd;
gf_region_data rd;

if (val == 0) { gf_multby_zero(dest, bytes, xor); return; }
if (val == 1) { gf_multby_one(src, dest, bytes, xor); return; }

gf_set_region_data(&rd, gf, src, dest, bytes, val, xor, 16);
gf_do_initial_region_alignment(&rd);

s8 = (uint8_t *) rd.s_start;
d8 = (uint8_t *) rd.d_start;

btd = (struct gf_bytwo_data *) ((gf_internal_t *) (gf->scratch))->private;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

if (xor) {
while (d8 < (uint8_t *) rd.d_top) {
tb = val;
while (1) {
if (tb & 1) vb = _mm_xor_si128(vb, va);
tb >>= 1;
if (tb == 0) break;
SSE_AB2(pp, m1, m2, va, t1, t2);
}
_mm_store_si128((__m128i *)d8, vb);
d8 += 16;
s8 += 16;
}
} else {
while (d8 < (uint8_t *) rd.d_top) {
vb = _mm_setzero_si128 ();
tb = val;
while (1) {
if (tb & 1) vb = _mm_xor_si128(vb, va);
tb >>= 1;
if (tb == 0) break;
t1 = _mm_and_si128(_mm_slli_epi64(va, 1), m1);
t2 = _mm_and_si128(va, m2);
t2 = _mm_sub_epi64 (
_mm_slli_epi64(t2, 1), _mm_srli_epi64(t2, (GF_FIELD_WIDTH-1)));
va = _mm_xor_si128(t1, _mm_and_si128(t2, pp));
}
_mm_store_si128((__m128i *)d8, vb);
d8 += 16;
s8 += 16;
}
}
gf_do_final_region_alignment(&rd);
#endif
}
*/

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_region_2_noxor(gf_region_data *rd, struct gf_bytwo_data *btd)
{
uint8_t *d8, *s8;
__m128i pp, m1, t1, t2, va;

s8 = (uint8_t *) rd->s_start;
d8 = (uint8_t *) rd->d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

while (d8 < (uint8_t *) rd->d_top) {
SSE_AB2(pp, m1, va, t1, t2);
_mm_store_si128((__m128i *)d8, va);
d8 += 16;
s8 += 16;
}
}
#endif

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_region_2_xor(gf_region_data *rd, struct gf_bytwo_data *btd)
{
uint8_t *d8, *s8;
__m128i pp, m1, t1, t2, va, vb;

s8 = (uint8_t *) rd->s_start;
d8 = (uint8_t *) rd->d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

while (d8 < (uint8_t *) rd->d_top) {
SSE_AB2(pp, m1, va, t1, t2);
vb = _mm_xor_si128(vb, va);
_mm_store_si128((__m128i *)d8, vb);
d8 += 16;
s8 += 16;
}
}
#endif

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_region_4_noxor(gf_region_data *rd, struct gf_bytwo_data *btd)
{
uint8_t *d8, *s8;
__m128i pp, m1, t1, t2, va;

s8 = (uint8_t *) rd->s_start;
d8 = (uint8_t *) rd->d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

while (d8 < (uint8_t *) rd->d_top) {
SSE_AB2(pp, m1, va, t1, t2);
SSE_AB2(pp, m1, va, t1, t2);
_mm_store_si128((__m128i *)d8, va);
d8 += 16;
s8 += 16;
}
}
#endif

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_region_4_xor(gf_region_data *rd, struct gf_bytwo_data *btd)
{
uint8_t *d8, *s8;
__m128i pp, m1, t1, t2, va, vb;

s8 = (uint8_t *) rd->s_start;
d8 = (uint8_t *) rd->d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

while (d8 < (uint8_t *) rd->d_top) {
SSE_AB2(pp, m1, va, t1, t2);
SSE_AB2(pp, m1, va, t1, t2);
vb = _mm_xor_si128(vb, va);
_mm_store_si128((__m128i *)d8, vb);
d8 += 16;
s8 += 16;
}
}
#endif

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_region_3_noxor(gf_region_data *rd, struct gf_bytwo_data *btd)
{
uint8_t *d8, *s8;
__m128i pp, m1, t1, t2, va, vb;

s8 = (uint8_t *) rd->s_start;
d8 = (uint8_t *) rd->d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

while (d8 < (uint8_t *) rd->d_top) {
vb = va;
SSE_AB2(pp, m1, va, t1, t2);
va = _mm_xor_si128(va, vb);
_mm_store_si128((__m128i *)d8, va);
d8 += 16;
s8 += 16;
}
}
#endif

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_region_3_xor(gf_region_data *rd, struct gf_bytwo_data *btd)
{
uint8_t *d8, *s8;
__m128i pp, m1, t1, t2, va, vb;

s8 = (uint8_t *) rd->s_start;
d8 = (uint8_t *) rd->d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

while (d8 < (uint8_t *) rd->d_top) {
vb = _mm_xor_si128(_mm_load_si128 ((__m128i *)(d8)), va);
SSE_AB2(pp, m1, va, t1, t2);
vb = _mm_xor_si128(vb, va);
_mm_store_si128((__m128i *)d8, vb);
d8 += 16;
s8 += 16;
}
}
#endif

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_region_5_noxor(gf_region_data *rd, struct gf_bytwo_data *btd)
{
uint8_t *d8, *s8;
__m128i pp, m1, t1, t2, va, vb;

s8 = (uint8_t *) rd->s_start;
d8 = (uint8_t *) rd->d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

while (d8 < (uint8_t *) rd->d_top) {
vb = va;
SSE_AB2(pp, m1, va, t1, t2);
SSE_AB2(pp, m1, va, t1, t2);
va = _mm_xor_si128(va, vb);
_mm_store_si128((__m128i *)d8, va);
d8 += 16;
s8 += 16;
}
}
#endif

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_region_5_xor(gf_region_data *rd, struct gf_bytwo_data *btd)
{
uint8_t *d8, *s8;
__m128i pp, m1, t1, t2, va, vb;

s8 = (uint8_t *) rd->s_start;
d8 = (uint8_t *) rd->d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

while (d8 < (uint8_t *) rd->d_top) {
vb = _mm_xor_si128(_mm_load_si128 ((__m128i *)(d8)), va);
SSE_AB2(pp, m1, va, t1, t2);
SSE_AB2(pp, m1, va, t1, t2);
vb = _mm_xor_si128(vb, va);
_mm_store_si128((__m128i *)d8, vb);
d8 += 16;
s8 += 16;
}
}
#endif

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_region_7_noxor(gf_region_data *rd, struct gf_bytwo_data *btd)
{
uint8_t *d8, *s8;
__m128i pp, m1, t1, t2, va, vb;

s8 = (uint8_t *) rd->s_start;
d8 = (uint8_t *) rd->d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

while (d8 < (uint8_t *) rd->d_top) {
vb = va;
SSE_AB2(pp, m1, va, t1, t2);
vb = _mm_xor_si128(va, vb);
SSE_AB2(pp, m1, va, t1, t2);
va = _mm_xor_si128(va, vb);
_mm_store_si128((__m128i *)d8, va);
d8 += 16;
s8 += 16;
}
}
#endif

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_region_7_xor(gf_region_data *rd, struct gf_bytwo_data *btd)
{
uint8_t *d8, *s8;
__m128i pp, m1, t1, t2, va, vb;

s8 = (uint8_t *) rd->s_start;
d8 = (uint8_t *) rd->d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

while (d8 < (uint8_t *) rd->d_top) {
vb = _mm_xor_si128(_mm_load_si128 ((__m128i *)(d8)), va);
SSE_AB2(pp, m1, va, t1, t2);
vb = _mm_xor_si128(vb, va);
SSE_AB2(pp, m1, va, t1, t2);
vb = _mm_xor_si128(vb, va);
_mm_store_si128((__m128i *)d8, vb);
d8 += 16;
s8 += 16;
}
}
#endif

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_region_6_noxor(gf_region_data *rd, struct gf_bytwo_data *btd)
{
uint8_t *d8, *s8;
__m128i pp, m1, t1, t2, va, vb;

s8 = (uint8_t *) rd->s_start;
d8 = (uint8_t *) rd->d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

while (d8 < (uint8_t *) rd->d_top) {
SSE_AB2(pp, m1, va, t1, t2);
vb = va;
SSE_AB2(pp, m1, va, t1, t2);
va = _mm_xor_si128(va, vb);
_mm_store_si128((__m128i *)d8, va);
d8 += 16;
s8 += 16;
}
}
#endif

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_region_6_xor(gf_region_data *rd, struct gf_bytwo_data *btd)
{
uint8_t *d8, *s8;
__m128i pp, m1, t1, t2, va, vb;

s8 = (uint8_t *) rd->s_start;
d8 = (uint8_t *) rd->d_start;

pp = _mm_set1_epi8(btd->prim_poly&0xff);

while (d8 < (uint8_t *) rd->d_top) {
SSE_AB2(pp, m1, va, t1, t2);
vb = _mm_xor_si128(_mm_load_si128 ((__m128i *)(d8)), va);
SSE_AB2(pp, m1, va, t1, t2);
vb = _mm_xor_si128(vb, va);
_mm_store_si128((__m128i *)d8, vb);
d8 += 16;
s8 += 16;
}
}
#endif

#ifdef INTEL_SSE2
static
void
gf_w4_bytwo_b_sse_multiply_region(gf_t *gf, void *src, void *dest, gf_val_32_t val, int bytes, int xor)
{
uint8_t *d8, *s8, tb;
__m128i pp, m1, m2, t1, t2, va, vb;
struct gf_bytwo_data *btd;
gf_region_data rd;

if (val == 0) { gf_multby_zero(dest, bytes, xor); return; }
if (val == 1) { gf_multby_one(src, dest, bytes, xor); return; }

gf_set_region_data(&rd, gf, src, dest, bytes, val, xor, 16);
gf_do_initial_region_alignment(&rd);

s8 = (uint8_t *) rd.s_start;
d8 = (uint8_t *) rd.d_start;

btd = (struct gf_bytwo_data *) ((gf_internal_t *) (gf->scratch))->private;

switch (val) {
case 2:
if (!xor) {
gf_w4_bytwo_b_sse_region_2_noxor(&rd, btd);
} else {
gf_w4_bytwo_b_sse_region_2_xor(&rd, btd);
}
gf_do_final_region_alignment(&rd);
return;
case 3:
if (!xor) {
gf_w4_bytwo_b_sse_region_3_noxor(&rd, btd);
} else {
gf_w4_bytwo_b_sse_region_3_xor(&rd, btd);
}
gf_do_final_region_alignment(&rd);
return;
case 4:
if (!xor) {
gf_w4_bytwo_b_sse_region_4_noxor(&rd, btd);
} else {
gf_w4_bytwo_b_sse_region_4_xor(&rd, btd);
}
gf_do_final_region_alignment(&rd);
return;
case 5:
if (!xor) {
gf_w4_bytwo_b_sse_region_5_noxor(&rd, btd);
} else {
gf_w4_bytwo_b_sse_region_5_xor(&rd, btd);
}
gf_do_final_region_alignment(&rd);
return;
case 6:
if (!xor) {
gf_w4_bytwo_b_sse_region_6_noxor(&rd, btd);
} else {
gf_w4_bytwo_b_sse_region_6_xor(&rd, btd);
}
gf_do_final_region_alignment(&rd);
return;
case 7:
if (!xor) {
gf_w4_bytwo_b_sse_region_7_noxor(&rd, btd);
} else {
gf_w4_bytwo_b_sse_region_7_xor(&rd, btd);
}
gf_do_final_region_alignment(&rd);
return;
}

pp = _mm_set1_epi8(btd->prim_poly&0xff);

if (xor) {
while (d8 < (uint8_t *) rd.d_top) {
tb = val;
while (1) {
if (tb & 1) vb = _mm_xor_si128(vb, va);
tb >>= 1;
if (tb == 0) break;
SSE_AB2(pp, m1, va, t1, t2);
}
_mm_store_si128((__m128i *)d8, vb);
d8 += 16;
s8 += 16;
}
} else {
while (d8 < (uint8_t *) rd.d_top) {
vb = _mm_setzero_si128 ();
tb = val;
while (1) {
if (tb & 1) vb = _mm_xor_si128(vb, va);
tb >>= 1;
if (tb == 0) break;
t1 = _mm_and_si128(_mm_slli_epi64(va, 1), m1);
t2 = _mm_and_si128(va, m2);
t2 = _mm_sub_epi64 (
_mm_slli_epi64(t2, 1), _mm_srli_epi64(t2, (GF_FIELD_WIDTH-1)));
va = _mm_xor_si128(t1, _mm_and_si128(t2, pp));
}
_mm_store_si128((__m128i *)d8, vb);
d8 += 16;
s8 += 16;
}
}
gf_do_final_region_alignment(&rd);
}
#endif

static
void
gf_w4_bytwo_b_nosse_multiply_region(gf_t *gf, void *src, void *dest, gf_val_32_t val, int bytes, int xor)
{
uint64_t *s64, *d64, t1, t2, ta, tb, prod;
struct gf_bytwo_data *btd;
gf_region_data rd;

if (val == 0) { gf_multby_zero(dest, bytes, xor); return; }
if (val == 1) { gf_multby_one(src, dest, bytes, xor); return; }

gf_set_region_data(&rd, gf, src, dest, bytes, val, xor, 16);
gf_do_initial_region_alignment(&rd);

btd = (struct gf_bytwo_data *) ((gf_internal_t *) (gf->scratch))->private;
s64 = (uint64_t *) rd.s_start;
d64 = (uint64_t *) rd.d_start;

switch (val) {
case 1:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
*d64 ^= *s64;
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
*d64 = *s64;
d64++;
s64++;
}
}
break;
case 2:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
*d64 ^= ta;
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
*d64 = ta;
d64++;
s64++;
}
}
break;
case 3:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
*d64 ^= (ta ^ prod);
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
*d64 = (ta ^ prod);
d64++;
s64++;
}
}
break;
case 4:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
*d64 ^= ta;
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
*d64 = ta;
d64++;
s64++;
}
}
break;
case 5:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
*d64 ^= (ta ^ prod);
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
*d64 = ta ^ prod;
d64++;
s64++;
}
}
break;
case 6:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
*d64 ^= (ta ^ prod);
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
*d64 = ta ^ prod;
d64++;
s64++;
}
}
break;
case 7:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
prod ^= ta;
*d64 ^= (ta ^ prod);
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
prod ^= ta;
*d64 = ta ^ prod;
d64++;
s64++;
}
}
break;
case 8:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
*d64 ^= ta;
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
*d64 = ta;
d64++;
s64++;
}
}
break;
case 9:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
*d64 ^= (ta ^ prod);
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
*d64 = (ta ^ prod);
d64++;
s64++;
}
}
break;
case 10:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
*d64 ^= (ta ^ prod);
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
*d64 = (ta ^ prod);
d64++;
s64++;
}
}
break;
case 11:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
prod ^= ta;
*d64 ^= (ta ^ prod);
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
prod ^= ta;
*d64 = (ta ^ prod);
d64++;
s64++;
}
}
break;
case 12:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
*d64 ^= (ta ^ prod);
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
*d64 = (ta ^ prod);
d64++;
s64++;
}
}
break;
case 13:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
prod ^= ta;
*d64 ^= (ta ^ prod);
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
prod ^= ta;
*d64 = (ta ^ prod);
d64++;
s64++;
}
}
break;
case 14:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
prod ^= ta;
*d64 ^= (ta ^ prod);
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
prod ^= ta;
*d64 = (ta ^ prod);
d64++;
s64++;
}
}
break;
case 15:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
prod ^= ta;
prod ^= ta;
*d64 ^= (ta ^ prod);
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
ta = *s64;
prod = ta;
prod ^= ta;
prod ^= ta;
*d64 = (ta ^ prod);
d64++;
s64++;
}
}
break;
default:
if (xor) {
while (d64 < (uint64_t *) rd.d_top) {
prod = *d64 ;
ta = *s64;
tb = val;
while (1) {
if (tb & 1) prod ^= ta;
tb >>= 1;
if (tb == 0) break;
}
*d64 = prod;
d64++;
s64++;
}
} else {
while (d64 < (uint64_t *) rd.d_top) {
prod = 0 ;
ta = *s64;
tb = val;
while (1) {
if (tb & 1) prod ^= ta;
tb >>= 1;
if (tb == 0) break;
}
*d64 = prod;
d64++;
s64++;
}
}
break;
}
gf_do_final_region_alignment(&rd);
}

static
int gf_w4_bytwo_init(gf_t *gf)
{
gf_internal_t *h;
uint64_t ip, m1, m2;
struct gf_bytwo_data *btd;

h = (gf_internal_t *) gf->scratch;
btd = (struct gf_bytwo_data *) (h->private);
ip = h->prim_poly & 0xf;
m1 = 0xe;
m2 = 0x8;
btd->prim_poly = 0;

while (ip != 0) {
btd->prim_poly |= ip;
ip <<= GF_FIELD_WIDTH;
m1 <<= GF_FIELD_WIDTH;
m2 <<= GF_FIELD_WIDTH;
}

if (h->mult_type == GF_MULT_BYTWO_p) {
gf->multiply.w32 = gf_w4_bytwo_p_multiply;
#ifdef INTEL_SSE2
if (h->region_type & GF_REGION_NOSIMD)
gf->multiply_region.w32 = gf_w4_bytwo_p_nosse_multiply_region;
else
gf->multiply_region.w32 = gf_w4_bytwo_p_sse_multiply_region;
#else
gf->multiply_region.w32 = gf_w4_bytwo_p_nosse_multiply_region;
if (h->region_type & GF_REGION_SIMD)
return 0;
#endif
} else {
gf->multiply.w32 = gf_w4_bytwo_b_multiply;
#ifdef INTEL_SSE2
if (h->region_type & GF_REGION_NOSIMD)
gf->multiply_region.w32 = gf_w4_bytwo_b_nosse_multiply_region;
else
gf->multiply_region.w32 = gf_w4_bytwo_b_sse_multiply_region;
#else
gf->multiply_region.w32 = gf_w4_bytwo_b_nosse_multiply_region;
if (h->region_type & GF_REGION_SIMD)
return 0;
#endif
}
return 1;
}

static
int gf_w4_cfm_init(gf_t *gf)
{
#if defined(INTEL_SSE4_PCLMUL)
gf->multiply.w32 = gf_w4_clm_multiply;
return 1;
#elif defined(ARM_NEON)
return gf_w4_neon_cfm_init(gf);
#endif
return 0;
}

static
int gf_w4_shift_init(gf_t *gf)
{
gf->multiply.w32 = gf_w4_shift_multiply;
return 1;
}

/* JSP: I'm putting all error-checking into gf_error_check(), so you don't
have to do error checking in scratch_size or in init */

int gf_w4_scratch_size(int mult_type, int region_type, int divide_type, int arg1, int arg2)
{
int issse3 = 0, isneon = 0;

#ifdef INTEL_SSSE3
issse3 = 1;
#endif
#ifdef ARM_NEON
isneon = 1;
#endif

switch(mult_type)
{
case GF_MULT_BYTWO_p:
case GF_MULT_BYTWO_b:
return sizeof(gf_internal_t) + sizeof(struct gf_bytwo_data);
break;
case GF_MULT_DEFAULT:
case GF_MULT_TABLE:
if (region_type == GF_REGION_CAUCHY) {
return sizeof(gf_internal_t) + sizeof(struct gf_single_table_data) + 64;
}

if (mult_type == GF_MULT_DEFAULT && !(issse3 || isneon))
region_type = GF_REGION_DOUBLE_TABLE;

if (region_type & GF_REGION_DOUBLE_TABLE) {
return sizeof(gf_internal_t) + sizeof(struct gf_double_table_data) + 64;
} else if (region_type & GF_REGION_QUAD_TABLE) {
if ((region_type & GF_REGION_LAZY) == 0) {
return sizeof(gf_internal_t) + sizeof(struct gf_quad_table_data) + 64;
} else {
return sizeof(gf_internal_t) + sizeof(struct gf_quad_table_lazy_data) + 64;
}
} else {
return sizeof(gf_internal_t) + sizeof(struct gf_single_table_data) + 64;
}
break;

case GF_MULT_LOG_TABLE:
return sizeof(gf_internal_t) + sizeof(struct gf_logtable_data) + 64;
break;
case GF_MULT_CARRY_FREE:
return sizeof(gf_internal_t);
break;
case GF_MULT_SHIFT:
return sizeof(gf_internal_t);
break;
default:
return 0;
}
return 0;
}

int
gf_w4_init (gf_t *gf)
{
gf_internal_t *h;

h = (gf_internal_t *) gf->scratch;
if (h->prim_poly == 0) h->prim_poly = 0x13;
h->prim_poly |= 0x10;
gf->multiply.w32 = NULL;
gf->divide.w32 = NULL;
gf->inverse.w32 = NULL;
gf->multiply_region.w32 = NULL;
gf->extract_word.w32 = gf_w4_extract_word;

switch(h->mult_type) {
case GF_MULT_CARRY_FREE: if (gf_w4_cfm_init(gf) == 0) return 0; break;
case GF_MULT_SHIFT:      if (gf_w4_shift_init(gf) == 0) return 0; break;
case GF_MULT_BYTWO_p:
case GF_MULT_BYTWO_b:    if (gf_w4_bytwo_init(gf) == 0) return 0; break;
case GF_MULT_LOG_TABLE:  if (gf_w4_log_init(gf) == 0) return 0; break;
case GF_MULT_DEFAULT:
case GF_MULT_TABLE:      if (gf_w4_table_init(gf) == 0) return 0; break;
default: return 0;
}

if (h->divide_type == GF_DIVIDE_EUCLID) {
gf->divide.w32 = gf_w4_divide_from_inverse;
gf->inverse.w32 = gf_w4_euclid;
} else if (h->divide_type == GF_DIVIDE_MATRIX) {
gf->divide.w32 = gf_w4_divide_from_inverse;
gf->inverse.w32 = gf_w4_matrix;
}

if (gf->divide.w32 == NULL) {
gf->divide.w32 = gf_w4_divide_from_inverse;
if (gf->inverse.w32 == NULL) gf->inverse.w32 = gf_w4_euclid;
}

if (gf->inverse.w32 == NULL)  gf->inverse.w32 = gf_w4_inverse_from_divide;

if (h->region_type == GF_REGION_CAUCHY) {
gf->multiply_region.w32 = gf_wgen_cauchy_region;
gf->extract_word.w32 = gf_wgen_extract_word;
}

if (gf->multiply_region.w32 == NULL) {
gf->multiply_region.w32 = gf_w4_multiply_region_from_single;
}

return 1;
}

/* Inline setup functions */

uint8_t *gf_w4_get_mult_table(gf_t *gf)
{
gf_internal_t *h;
struct gf_single_table_data *std;

h = (gf_internal_t *) gf->scratch;
if (gf->multiply.w32 == gf_w4_single_table_multiply) {
std = (struct gf_single_table_data *) h->private;
return (uint8_t *) std->mult;
}
return NULL;
}

uint8_t *gf_w4_get_div_table(gf_t *gf)
{
gf_internal_t *h;
struct gf_single_table_data *std;

h = (gf_internal_t *) gf->scratch;
if (gf->multiply.w32 == gf_w4_single_table_multiply) {
std = (struct gf_single_table_data *) h->private;
return (uint8_t *) std->div;
}
return NULL;
}

``````