Avoid memcpy for txdataF_BF if no precoding

In order to speed up processing if precoding is disabled, we just copy
the pointer from txdataF to txdataF_BF, as opposed to do a full memcpy()
to duplicate the data. The same happens if we cannot have precoding,
i.e., in SISO.

Handle the case of precoding in allocation of the txdataF_BF structure
accordingly.

openair1/PHY/INIT/nr_init_ru.c

@@ -192,8 +192,14 @@ void nr_phy_free_RU(RU_t *ru)
     free_and_zero(ru->common.txdataF);
 
     // free IFFT input buffers (TX)
-    for (i = 0; i < ru->nb_tx; i++) free_and_zero(ru->common.txdataF_BF[i]);
-    free_and_zero(ru->common.txdataF_BF);
+    // nr_feptx_prec(): if no precoding, it just copies pointers instead of memory
+    // note that we still allocate that memory in nr_phy_init_RU(), otherwise
+    // we cannot execute in the first iteration because XYZ
+    bool no_precoding = ru->do_precoding == 0 || (ru->nb_tx == 1 && ru->nb_log_antennas == 1);
+    if (!no_precoding) {
+      for (i = 0; i < ru->nb_tx; i++) free_and_zero(ru->common.txdataF_BF[i]);
+      free_and_zero(ru->common.txdataF_BF);
+    }
 
     // free FFT output buffers (RX)
     for (i = 0; i < ru->nb_rx; i++) free_and_zero(ru->common.rxdataF[i]);

openair1/SCHED_NR/nr_ru_procedures.c

@@ -188,27 +188,19 @@ void nr_feptx_prec(RU_t *ru,int frame_tx,int tti_tx) {
 
     if (nr_slot_select(cfg,frame_tx,slot_tx) == NR_UPLINK_SLOT) return;
 
-    for(i=0; i<ru->nb_log_antennas; ++i) {
-      memcpy((void*)ru->common.txdataF[i],
-           (void*)&gNB->common_vars.txdataF[i][txdataF_offset],
-           fp->samples_per_slot_wCP*sizeof(int32_t));
-      if (ru->do_precoding == 1)
+    if (ru->do_precoding == 0 || (ru->nb_tx == 1 && ru->nb_log_antennas == 1)) {
+      for (i = 0; i < ru->nb_log_antennas; ++i)
+        ru->common.txdataF_BF[i] = (int32_t *)&gNB->common_vars.txdataF[i][txdataF_offset];
+    }
+    else {
+      for(i=0; i<ru->nb_log_antennas; ++i) {
+        memcpy((void*)ru->common.txdataF[i],
+               (void*)&gNB->common_vars.txdataF[i][txdataF_offset],
+               fp->samples_per_slot_wCP*sizeof(int32_t));
 	memcpy((void*)&ru->common.beam_id[i][slot_tx*fp->symbols_per_slot],
 	       (void*)&gNB->common_vars.beam_id[i][slot_tx*fp->symbols_per_slot],
 	       fp->symbols_per_slot*sizeof(uint8_t));
-    }
-
-    if (ru->nb_tx == 1 && ru->nb_log_antennas == 1) {
-    
-      VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PHY_PROCEDURES_RU_FEPTX_PREC , 1);
-
-      memcpy((void*)ru->common.txdataF_BF[0],
-             (void*)ru->common.txdataF[0],
-             fp->samples_per_slot_wCP*sizeof(int32_t));
-
-      VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_PHY_PROCEDURES_RU_FEPTX_PREC , 0);
-    }// if (ru->nb_tx == 1)
-    else {
+      }
       bw  = ru->beam_weights[0];
       for (l=0;l<fp->symbols_per_slot;l++) {
         for (aa=0;aa<ru->nb_tx;aa++) {
@@ -223,7 +215,7 @@ void nr_feptx_prec(RU_t *ru,int frame_tx,int tti_tx) {
                             0);
         }// for (aa=0;aa<ru->nb_tx;aa++)
       }// for (l=0;l<fp->symbols_per_slot;l++)
-    }// if (ru->nb_tx == 1)
+    }// ru->do_precoding
   }// if (ru->num_gNB == 1)
   stop_meas(&ru->precoding_stats);
 }