mirror of
https://github.com/servalproject/serval-dna.git
synced 2024-12-24 07:16:43 +00:00
82 lines
2.2 KiB
C
82 lines
2.2 KiB
C
|
/* Reed-Solomon encoder
|
||
|
|
* Copyright 2004, Phil Karn, KA9Q
|
||
|
|
* May be used under the terms of the GNU Lesser General Public License (LGPL)
|
||
|
|
*/
|
||
|
|
#include <string.h>
|
||
|
|
#include "fixed.h"
|
||
|
|
#ifdef __VEC__
|
||
|
|
#include <sys/sysctl.h>
|
||
|
|
#endif
|
||
|
|
|
||
|
|
|
||
|
|
static enum {UNKNOWN=0,MMX,SSE,SSE2,ALTIVEC,PORT} cpu_mode;
|
||
|
|
|
||
|
|
static void encode_rs_8_c(data_t *data, data_t *parity,int pad);
|
||
|
|
#if __vec__
|
||
|
|
static void encode_rs_8_av(data_t *data, data_t *parity,int pad);
|
||
|
|
#endif
|
||
|
|
|
||
|
|
void encode_rs_8(data_t *data, data_t *parity,int pad){
|
||
|
|
if(cpu_mode == UNKNOWN){
|
||
|
|
cpu_mode = PORT;
|
||
|
|
}
|
||
|
|
switch(cpu_mode){
|
||
|
|
#if __vec__
|
||
|
|
case ALTIVEC:
|
||
|
|
encode_rs_8_av(data,parity,pad);
|
||
|
|
return;
|
||
|
|
#endif
|
||
|
|
#if __i386__
|
||
|
|
case MMX:
|
||
|
|
case SSE:
|
||
|
|
case SSE2:
|
||
|
|
#endif
|
||
|
|
default:
|
||
|
|
encode_rs_8_c(data,parity,pad);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
#if __vec__ /* PowerPC G4/G5 Altivec instructions are available */
|
||
|
|
|
||
|
|
static vector unsigned char reverse = (vector unsigned char)(0,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1);
|
||
|
|
static vector unsigned char shift_right = (vector unsigned char)(15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30);
|
||
|
|
|
||
|
|
/* Lookup table for feedback multiplications
|
||
|
|
* These are the low half of the coefficients. Since the generator polynomial is
|
||
|
|
* palindromic, we form the other half by reversing this one
|
||
|
|
*/
|
||
|
|
extern static union { vector unsigned char v; unsigned char c[16]; } table[256];
|
||
|
|
|
||
|
|
static void encode_rs_8_av(data_t *data, data_t *parity,int pad){
|
||
|
|
union { vector unsigned char v[2]; unsigned char c[32]; } shift_register;
|
||
|
|
int i;
|
||
|
|
|
||
|
|
shift_register.v[0] = (vector unsigned char)(0);
|
||
|
|
shift_register.v[1] = (vector unsigned char)(0);
|
||
|
|
|
||
|
|
for(i=0;i<NN-NROOTS-pad;i++){
|
||
|
|
vector unsigned char feedback0,feedback1;
|
||
|
|
unsigned char f;
|
||
|
|
|
||
|
|
f = data[i] ^ shift_register.c[31];
|
||
|
|
feedback1 = table[f].v;
|
||
|
|
feedback0 = vec_perm(feedback1,feedback1,reverse);
|
||
|
|
|
||
|
|
/* Shift right one byte */
|
||
|
|
shift_register.v[1] = vec_perm(shift_register.v[0],shift_register.v[1],shift_right) ^ feedback1;
|
||
|
|
shift_register.v[0] = vec_sro(shift_register.v[0],(vector unsigned char)(8)) ^ feedback0;
|
||
|
|
shift_register.c[0] = f;
|
||
|
|
}
|
||
|
|
for(i=0;i<NROOTS;i++)
|
||
|
|
parity[NROOTS-i-1] = shift_register.c[i];
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* Portable C version */
|
||
|
|
static void encode_rs_8_c(data_t *data, data_t *parity,int pad){
|
||
|
|
|
||
|
|
#include "encode_rs.h"
|
||
|
|
|
||
|
|
}
|