[MN-dev] [mndiff]: r148 - in trunk/noe: ldpc.c ldpc.h test_ldpc.c

[michael]

Author: michael
Date: Sat Apr 11 23:42:47 2009
New Revision: 148

Log:
Work with 32bits at a time for GF(2) LDPC, 4x faster.

Modified:
   trunk/noe/ldpc.c
   trunk/noe/ldpc.h
   trunk/noe/test_ldpc.c

Modified: trunk/noe/ldpc.c
==============================================================================
--- trunk/noe/ldpc.c	Sat Apr 11 23:19:18 2009	(r147)
+++ trunk/noe/ldpc.c	Sat Apr 11 23:42:47 2009	(r148)
@@ -35,7 +35,7 @@
 
 typedef struct LDPCContext{
     unsigned int (*parity_matrix)[2][MAX_NZC];
-    GFF4Element (*inv_matrix)[2];
+    int (*inv_matrix)[2];
     int parity_len;
     int data_len;
     int nzc;
@@ -251,11 +251,11 @@ int EXT(init_matrixLDPC)(LDPCContext *c,
     return rank - erasure_count;
 }
 
-int EXT(decodeLDPC)(LDPCContext *c, uint8_t *code, int erasure_count, int erasure_pos[]){
+int EXT(decodeLDPC)(LDPCContext *c, LDPC_ELEM *code, int erasure_count, int erasure_pos[]){
     int i,j;
     int parity_len= c->parity_len;
     int   code_len= c->data_len + parity_len;
-    GFF4Element syndrom[2*c->parity_len];
+    unsigned int syndrom[2*c->parity_len];
     memset(syndrom, 0, sizeof(syndrom));
 
     for(i=0; i<erasure_count; i++)
@@ -263,7 +263,7 @@ int EXT(decodeLDPC)(LDPCContext *c, uint
 
 #if SIZE == 2
     for(i=0; i<code_len; i++){
-        GFF4Element v= code[i];
+        unsigned int v= code[i];
         for(j=0; j<c->nzc; j++){
             int y= c->parity_matrix[i][0][j] + c->parity_len;
             int p= -EXT(exp)[c->parity_matrix[i][1][j]];
@@ -273,7 +273,7 @@ int EXT(decodeLDPC)(LDPCContext *c, uint
 
     j=0;
     for(i=erasure_count-1; i>=0; i--){
-        GFF4Element v=0;
+        unsigned int v=0;
         int idx= c->inv_matrix[j][0];
         while(idx<2*parity_len){
             v^= syndrom[idx] & c->inv_matrix[j++][1];
@@ -285,7 +285,7 @@ int EXT(decodeLDPC)(LDPCContext *c, uint
     }
 #else
     for(i=0; i<code_len; i++){
-        GFF4Element v= EXT(log)[ code[i] ];
+        unsigned int v= EXT(log)[ code[i] ];
         for(j=0; j<c->nzc; j++){
             int y= c->parity_matrix[i][0][j] + c->parity_len;
             int p= c->parity_matrix[i][1][j];
@@ -298,7 +298,7 @@ int EXT(decodeLDPC)(LDPCContext *c, uint
 
     j=0;
     for(i=erasure_count-1; i>=0; i--){
-        GFF4Element v=0;
+        unsigned int v=0;
         int idx= c->inv_matrix[j][0];
         while(idx<2*parity_len){
             v= sum(v, EXT(exp)[syndrom[idx] + c->inv_matrix[j++][1]]);

Modified: trunk/noe/ldpc.h
==============================================================================
--- trunk/noe/ldpc.h	Sat Apr 11 23:19:18 2009	(r147)
+++ trunk/noe/ldpc.h	Sat Apr 11 23:42:47 2009	(r148)
@@ -18,6 +18,12 @@
 
 struct LDPCContext;
 
+#if SIZE==2
+    typedef uint32_t LDPC_ELEM;
+#else
+    typedef uint8_t  LDPC_ELEM;
+#endif
+
 /**
  *
  * @param nzc number of non zero elements per column, 0 means choose automatically.
@@ -38,6 +44,6 @@ int EXT(init_matrixLDPC)(struct LDPCCont
  * @param erasure_count must match what has been passed to init_matrixLDPC
  * @param erasure_pos must match what has been passed to init_matrixLDPC
  */
-int EXT(decodeLDPC)(struct LDPCContext *c, uint8_t *code, int erasure_count, int erasure_pos[]);
+int EXT(decodeLDPC)(struct LDPCContext *c, LDPC_ELEM *code, int erasure_count, int erasure_pos[]);
 
 void EXT(freeLDPC)(struct LDPCContext *c);

Modified: trunk/noe/test_ldpc.c
==============================================================================
--- trunk/noe/test_ldpc.c	Sat Apr 11 23:19:18 2009	(r147)
+++ trunk/noe/test_ldpc.c	Sat Apr 11 23:42:47 2009	(r148)
@@ -61,13 +61,13 @@ int main(){
             for(erasure_count= reliable ? parity_len-(SIZE==2 ? 4 : 1) : parity_len*3/4; ; erasure_count--){
                 int fail=0;
                 for(try=0; try<10; try++){
-                    uint8_t code[code_len], code_bak[code_len];
+                    LDPC_ELEM code[code_len], code_bak[code_len];
                     int erasure_pos[erasure_count];
 
                     for(i=0; i<data_len; i++)
                         code[i]= code_bak[i]= get_random(&kiss);
                     EXT(decodeLDPC)(enc, code, parity_len, parity_pos);
-                    memcpy(code_bak+data_len, code+data_len, parity_len);
+                    memcpy(code_bak+data_len, code+data_len, parity_len * sizeof(*code));
                     for(i=0; i<code_len; i++)
                         if(code[i] != code_bak[i])
                             fprintf(stderr, "FATALXX error %X!= %X at %d\n", code[i], code_bak[i], i);
@@ -76,7 +76,7 @@ int main(){
                         do{
                             x= get_random(&kiss) % code_len;
                         }while(code[x] != code_bak[x]);
-                        code[x]+= get_random(&kiss)%255+1;
+                        code[x]+= get_random(&kiss)%(8*sizeof(LDPC_ELEM)-1)+1;
                         erasure_pos[i]= x;
                     }