mirror of
https://git.code.sf.net/p/zint/code
synced 2025-05-21 02:35:14 -04:00
TELEPEN: fix stop length (14 -> 12)
reedsol.c: some performance gain by stashing generated poly logs and pre-checking if has a zero coeff to avoid inner loop branch
This commit is contained in:
gitlost
parent
7e3d0f2405
commit
21d015a84a
4 changed files with 129 additions and 56 deletions
|
|
@ -91,7 +91,7 @@ INTERNAL void rs_init_gf(rs_t *rs, const unsigned int prime_poly) {
|
|||
|
||||
/* Using bits 9-6 as hash to save a few cycles */
|
||||
/* Alter this hash or just iterate if new prime poly added that doesn't fit */
|
||||
unsigned int hash = prime_poly >> 5;
|
||||
const unsigned int hash = prime_poly >> 5;
|
||||
|
||||
rs->logt = data[hash].logt;
|
||||
rs->alog = data[hash].alog;
|
||||
|
|
@ -109,6 +109,7 @@ INTERNAL void rs_init_code(rs_t *rs, const int nsym, int index) {
|
|||
const unsigned char *const logt = rs->logt;
|
||||
const unsigned char *const alog = rs->alog;
|
||||
unsigned char *rspoly = rs->rspoly;
|
||||
unsigned char *log_rspoly = rs->log_rspoly;
|
||||
|
||||
rs->nsym = nsym;
|
||||
|
||||
|
|
@ -123,6 +124,13 @@ INTERNAL void rs_init_code(rs_t *rs, const int nsym, int index) {
|
|||
rspoly[0] = alog[logt[rspoly[0]] + index]; /* 2**(i + (i+1) + ... + index) */
|
||||
index++;
|
||||
}
|
||||
|
||||
/* Set logs of poly and check if have zero coeffs */
|
||||
rs->zero = 0;
|
||||
for (i = 0; i <= nsym; i++) {
|
||||
log_rspoly[i] = logt[rspoly[i]]; /* For simplicity allow log of 0 */
|
||||
rs->zero |= rspoly[i] == 0;
|
||||
}
|
||||
}
|
||||
|
||||
/* rs_encode(&rs, datalen, data, res) generates nsym Reed-Solomon codes (nsym as given in rs_init_code())
|
||||
|
|
@ -132,23 +140,40 @@ INTERNAL void rs_encode(const rs_t *rs, const int datalen, const unsigned char *
|
|||
const unsigned char *const logt = rs->logt;
|
||||
const unsigned char *const alog = rs->alog;
|
||||
const unsigned char *const rspoly = rs->rspoly;
|
||||
const unsigned char *const log_rspoly = rs->log_rspoly;
|
||||
const int nsym = rs->nsym;
|
||||
|
||||
memset(res, 0, nsym);
|
||||
for (i = 0; i < datalen; i++) {
|
||||
const unsigned int m = res[nsym - 1] ^ data[i];
|
||||
if (m) {
|
||||
const unsigned int log_m = logt[m];
|
||||
for (k = nsym - 1; k > 0; k--) {
|
||||
if (rspoly[k])
|
||||
res[k] = (unsigned char) (res[k - 1] ^ alog[log_m + logt[rspoly[k]]]);
|
||||
else
|
||||
res[k] = res[k - 1];
|
||||
if (rs->zero) { /* Poly has a zero coeff so need to check in inner loop */
|
||||
for (i = 0; i < datalen; i++) {
|
||||
const unsigned int m = res[nsym - 1] ^ data[i];
|
||||
if (m) {
|
||||
const unsigned int log_m = logt[m];
|
||||
for (k = nsym - 1; k > 0; k--) {
|
||||
if (rspoly[k])
|
||||
res[k] = (unsigned char) (res[k - 1] ^ alog[log_m + log_rspoly[k]]);
|
||||
else
|
||||
res[k] = res[k - 1];
|
||||
}
|
||||
res[0] = alog[log_m + log_rspoly[0]];
|
||||
} else {
|
||||
memmove(res + 1, res, nsym - 1);
|
||||
res[0] = 0;
|
||||
}
|
||||
}
|
||||
} else { /* Avoid a branch in inner loop */
|
||||
for (i = 0; i < datalen; i++) {
|
||||
const unsigned int m = res[nsym - 1] ^ data[i];
|
||||
if (m) {
|
||||
const unsigned int log_m = logt[m];
|
||||
for (k = nsym - 1; k > 0; k--) {
|
||||
res[k] = (unsigned char) (res[k - 1] ^ alog[log_m + log_rspoly[k]]);
|
||||
}
|
||||
res[0] = alog[log_m + log_rspoly[0]];
|
||||
} else {
|
||||
memmove(res + 1, res, nsym - 1);
|
||||
res[0] = 0;
|
||||
}
|
||||
res[0] = alog[log_m + logt[rspoly[0]]]; /* rspoly[0] can't be zero */
|
||||
} else {
|
||||
memmove(res + 1, res, nsym - 1);
|
||||
res[0] = 0;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -160,23 +185,40 @@ INTERNAL void rs_encode_uint(const rs_t *rs, const int datalen, const unsigned i
|
|||
const unsigned char *const logt = rs->logt;
|
||||
const unsigned char *const alog = rs->alog;
|
||||
const unsigned char *const rspoly = rs->rspoly;
|
||||
const unsigned char *const log_rspoly = rs->log_rspoly;
|
||||
const int nsym = rs->nsym;
|
||||
|
||||
memset(res, 0, sizeof(unsigned int) * nsym);
|
||||
for (i = 0; i < datalen; i++) {
|
||||
const unsigned int m = res[nsym - 1] ^ data[i];
|
||||
if (m) {
|
||||
const unsigned int log_m = logt[m];
|
||||
for (k = nsym - 1; k > 0; k--) {
|
||||
if (rspoly[k])
|
||||
res[k] = res[k - 1] ^ alog[log_m + logt[rspoly[k]]];
|
||||
else
|
||||
res[k] = res[k - 1];
|
||||
if (rs->zero) { /* Poly has a zero coeff so need to check in inner loop */
|
||||
for (i = 0; i < datalen; i++) {
|
||||
const unsigned int m = res[nsym - 1] ^ data[i];
|
||||
if (m) {
|
||||
const unsigned int log_m = logt[m];
|
||||
for (k = nsym - 1; k > 0; k--) {
|
||||
if (rspoly[k])
|
||||
res[k] = res[k - 1] ^ alog[log_m + log_rspoly[k]];
|
||||
else
|
||||
res[k] = res[k - 1];
|
||||
}
|
||||
res[0] = alog[log_m + log_rspoly[0]];
|
||||
} else {
|
||||
memmove(res + 1, res, sizeof(unsigned int) * (nsym - 1));
|
||||
res[0] = 0;
|
||||
}
|
||||
}
|
||||
} else { /* Avoid a branch in inner loop */
|
||||
for (i = 0; i < datalen; i++) {
|
||||
const unsigned int m = res[nsym - 1] ^ data[i];
|
||||
if (m) {
|
||||
const unsigned int log_m = logt[m];
|
||||
for (k = nsym - 1; k > 0; k--) {
|
||||
res[k] = res[k - 1] ^ alog[log_m + log_rspoly[k]];
|
||||
}
|
||||
res[0] = alog[log_m + log_rspoly[0]];
|
||||
} else {
|
||||
memmove(res + 1, res, sizeof(unsigned int) * (nsym - 1));
|
||||
res[0] = 0;
|
||||
}
|
||||
res[0] = alog[log_m + logt[rspoly[0]]];
|
||||
} else {
|
||||
memmove(res + 1, res, sizeof(unsigned int) * (nsym - 1));
|
||||
res[0] = 0;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -223,9 +265,10 @@ INTERNAL int rs_uint_init_gf(rs_uint_t *rs_uint, const unsigned int prime_poly,
|
|||
|
||||
INTERNAL void rs_uint_init_code(rs_uint_t *rs_uint, const int nsym, int index) {
|
||||
int i, k;
|
||||
const unsigned int *logt = rs_uint->logt;
|
||||
const unsigned int *alog = rs_uint->alog;
|
||||
const unsigned int *const logt = rs_uint->logt;
|
||||
const unsigned int *const alog = rs_uint->alog;
|
||||
unsigned short *rspoly = rs_uint->rspoly;
|
||||
unsigned int *log_rspoly = rs_uint->log_rspoly;
|
||||
|
||||
if (logt == NULL || alog == NULL) {
|
||||
return;
|
||||
|
|
@ -243,34 +286,58 @@ INTERNAL void rs_uint_init_code(rs_uint_t *rs_uint, const int nsym, int index) {
|
|||
rspoly[0] = alog[(logt[rspoly[0]] + index)];
|
||||
index++;
|
||||
}
|
||||
|
||||
/* Set logs of poly and check if have zero coeffs */
|
||||
rs_uint->zero = 0;
|
||||
for (i = 0; i <= nsym; i++) {
|
||||
log_rspoly[i] = logt[rspoly[i]]; /* For simplicity allow log of 0 */
|
||||
rs_uint->zero |= rspoly[i] == 0;
|
||||
}
|
||||
}
|
||||
|
||||
INTERNAL void rs_uint_encode(const rs_uint_t *rs_uint, const int datalen, const unsigned int *data,
|
||||
unsigned int *res) {
|
||||
int i, k;
|
||||
const unsigned int *logt = rs_uint->logt;
|
||||
const unsigned int *alog = rs_uint->alog;
|
||||
const unsigned short *rspoly = rs_uint->rspoly;
|
||||
const unsigned int *const logt = rs_uint->logt;
|
||||
const unsigned int *const alog = rs_uint->alog;
|
||||
const unsigned short *const rspoly = rs_uint->rspoly;
|
||||
const unsigned int *const log_rspoly = rs_uint->log_rspoly;
|
||||
const int nsym = rs_uint->nsym;
|
||||
|
||||
memset(res, 0, sizeof(unsigned int) * nsym);
|
||||
if (logt == NULL || alog == NULL) {
|
||||
return;
|
||||
}
|
||||
for (i = 0; i < datalen; i++) {
|
||||
const unsigned int m = res[nsym - 1] ^ data[i];
|
||||
if (m) {
|
||||
const unsigned int log_m = logt[m];
|
||||
for (k = nsym - 1; k > 0; k--) {
|
||||
if (rspoly[k])
|
||||
res[k] = res[k - 1] ^ alog[log_m + logt[rspoly[k]]];
|
||||
else
|
||||
res[k] = res[k - 1];
|
||||
if (rs_uint->zero) { /* Poly has a zero coeff so need to check in inner loop */
|
||||
for (i = 0; i < datalen; i++) {
|
||||
const unsigned int m = res[nsym - 1] ^ data[i];
|
||||
if (m) {
|
||||
const unsigned int log_m = logt[m];
|
||||
for (k = nsym - 1; k > 0; k--) {
|
||||
if (rspoly[k])
|
||||
res[k] = res[k - 1] ^ alog[log_m + log_rspoly[k]];
|
||||
else
|
||||
res[k] = res[k - 1];
|
||||
}
|
||||
res[0] = alog[log_m + log_rspoly[0]];
|
||||
} else {
|
||||
memmove(res + 1, res, sizeof(unsigned int) * (nsym - 1));
|
||||
res[0] = 0;
|
||||
}
|
||||
}
|
||||
} else { /* Avoid a branch in inner loop */
|
||||
for (i = 0; i < datalen; i++) {
|
||||
const unsigned int m = res[nsym - 1] ^ data[i];
|
||||
if (m) {
|
||||
const unsigned int log_m = logt[m];
|
||||
for (k = nsym - 1; k > 0; k--) {
|
||||
res[k] = res[k - 1] ^ alog[log_m + log_rspoly[k]];
|
||||
}
|
||||
res[0] = alog[log_m + log_rspoly[0]];
|
||||
} else {
|
||||
memmove(res + 1, res, sizeof(unsigned int) * (nsym - 1));
|
||||
res[0] = 0;
|
||||
}
|
||||
res[0] = alog[log_m + logt[rspoly[0]]];
|
||||
} else {
|
||||
memmove(res + 1, res, sizeof(unsigned int) * (nsym - 1));
|
||||
res[0] = 0;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue