cleaning up viterbi neon

lib/src/phy/fec/viterbi37_neon.c

@@ -13,7 +13,6 @@
 #include "parity.h"
 
 //#define DEBUG
-//#define HAVE_NEON
 #ifdef HAVE_NEON
 
 #include <arm_neon.h>
@@ -22,8 +21,6 @@ typedef union {
   unsigned char c[64]; 
   uint8x16_t    v[4];   
 } metric_t;
-
-
 typedef union { 
   unsigned long  w[2]; 
   unsigned char  c[8]; 
@@ -31,7 +28,6 @@ typedef union {
   uint8x8_t v[1];  
 } decision_t;
 
-
 union branchtab27{
   unsigned char c[32];
   uint8x16_t v[2];
@@ -42,7 +38,6 @@ union branchtab27{
 int8x8_t mask_shift;
 
 
-int firstGo;
 /* State info for instance of Viterbi decoder */
 struct v37 {
   metric_t metrics1; /* path metric buffer 1 */
@@ -77,7 +72,6 @@ void clear_v37_neon(struct v37 *vp) {
 int init_viterbi37_neon(void *p, int starting_state) {
   struct v37 *vp = p;
   uint32_t i;
-  firstGo = 1;
   for(i=0;i<64;i++)
     vp->metrics1.c[i] = 63;
     
@@ -88,7 +82,6 @@ int init_viterbi37_neon(void *p, int starting_state) {
   mask_and = vdup_n_u8(0x80); 
   mask_shift = vld1_s8(xr);
 
-
   vp->old_metrics = &vp->metrics1;
   vp->new_metrics = &vp->metrics2;
   vp->dp = vp->decisions;
@@ -176,8 +169,7 @@ void print_uint8x16_t(char *s, uint8x16_t val) {
   printf("\n");
 }
 
-static inline int movemask_neon(uint8x16_t movemask_low_in)
+static inline int movemask_neon(uint8x16_t movemask_low_in) {
-{
   uint8x8_t lo = vget_low_u8(movemask_low_in);
   uint8x8_t hi = vget_high_u8(movemask_low_in);
   lo = vand_u8(lo, mask_and);
@@ -217,14 +209,13 @@ void update_viterbi37_blk_neon(void *p,unsigned char *syms,int nbits, uint32_t *
   
   while(nbits--) {
     uint8x16_t sym0v,sym1v,sym2v;
-    
     void *tmp;
     int i;
 
    // printf("nbits=%d, syms=%d,%d,%d\n", nbits, syms[0], syms[1], syms[2]);fflush(stdout);
     
     /* Splat the 0th symbol across sym0v, the 1st symbol across sym1v, etc */
-    sym0v = vld1q_dup_u8(syms);  // passing a char as opposed to a pointer to a char
+    sym0v = vld1q_dup_u8(syms); 
     sym1v = vld1q_dup_u8(syms+1); 
     sym2v = vld1q_dup_u8(syms+2);
     syms += 3;
@@ -246,49 +237,36 @@ void update_viterbi37_blk_neon(void *p,unsigned char *syms,int nbits, uint32_t *
       m2 = vaddq_u8(vp->old_metrics->v[i],m_metric);
       
       /* Compare and select, using modulo arithmetic */
-
-      
       decision0 = (uint8x16_t)vcgtq_s8(vsubq_s8((int8x16_t)m0,(int8x16_t)m1),vdupq_n_s8(0));
       decision1 = (uint8x16_t)vcgtq_s8(vsubq_s8((int8x16_t)m2,(int8x16_t)m3),vdupq_n_s8(0));
       survivor0 = vorrq_u8(vandq_u8(decision0,m1),vandq_u8(vmvnq_u8(decision0),m0));    
       survivor1 = vorrq_u8 (vandq_u8(decision1,m3),vandq_u8(vmvnq_u8(decision1),m2) );
 
-      ////// equal to _mm_unpacklo_epi8  //////////
+      /* Pack each set of decisions into 16 bits */
       uint8x8_t a1 = vget_low_u8(decision0);
       uint8x8_t b1 = vget_low_u8(decision1);
       uint8x8x2_t result = vzip_u8(a1, b1);
       uint8x16_t movemask_low_in =  vcombine_u8(result.val[0], result.val[1]);
-      ///////////////////////////////////////// 
 
-      
-      ////////equal to _mm_movemask_epi8 ////////
       d->s[2*i] = movemask_neon(movemask_low_in);
 	
-      ///////equal to _mm_unpackhi_epi8////////////
       a1 = vget_high_u8(decision0);
       b1 = vget_high_u8(decision1);
       result = vzip_u8(a1, b1);
       uint8x16_t movemask_hi_in = vcombine_u8(result.val[0], result.val[1]);
 
- 		
-
-	  ////////equal to _mm_movemask//////////////
       d->s[2*i+1] = movemask_neon(movemask_hi_in);
 
-
       a1 = vget_low_u8(survivor0);
       b1 = vget_low_u8(survivor1);
       result = vzip_u8(a1, b1);
       vp->new_metrics->v[2*i] =  vcombine_u8(result.val[0], result.val[1]);
 
-
       a1 = vget_high_u8(survivor0);
       b1 = vget_high_u8(survivor1);
       result = vzip_u8(a1, b1);
       vp->new_metrics->v[2*i+1] = vcombine_u8(result.val[0], result.val[1]);
       
- 
-      
      }
 
     // See if we need to normalize
@@ -315,8 +293,7 @@ void update_viterbi37_blk_neon(void *p,unsigned char *syms,int nbits, uint32_t *
       /* We cannot use a saturated subtract, because we often have to adjust by more than SHRT_MAX
        * This is okay since it can't overflow anyway
        */
-      for(i=0;i<4;i++)
+      for(i=0;i<4;i++) {
-      {
         vp->new_metrics->v[i] = vsubq_u8(vp->new_metrics->v[i],adjustv);
       }
    
@@ -326,7 +303,6 @@ void update_viterbi37_blk_neon(void *p,unsigned char *syms,int nbits, uint32_t *
     tmp = vp->old_metrics;
     vp->old_metrics = vp->new_metrics;
     vp->new_metrics = tmp;
-    //firstGo = 0;
   }
   
   if (best_state) {