From b7c14696163cff9d2dbb10be9bacbccac0817af8 Mon Sep 17 00:00:00 2001
From: Carles Fernandez <carles.fernandez@gmail.com>
Date: Sun, 3 May 2015 10:50:57 +0200
Subject: [PATCH] 20% of performance improvement

---
 .../libs/gps_sdr_signal_processing.cc         | 23 ++++--
 src/tests/arithmetic/code_generation_test.cc  | 80 +++++++++++++++++++
 src/tests/test_main.cc                        |  1 +
 3 files changed, 96 insertions(+), 8 deletions(-)
 create mode 100644 src/tests/arithmetic/code_generation_test.cc

diff --git a/src/algorithms/libs/gps_sdr_signal_processing.cc b/src/algorithms/libs/gps_sdr_signal_processing.cc
index 9037fc414..5ac0c19b5 100644
--- a/src/algorithms/libs/gps_sdr_signal_processing.cc
+++ b/src/algorithms/libs/gps_sdr_signal_processing.cc
@@ -37,10 +37,11 @@
 
 void gps_l1_ca_code_gen_complex(std::complex<float>* _dest, signed int _prn, unsigned int _chip_shift)
 {
-    unsigned int G1[1023];
-    unsigned int G2[1023];
-    unsigned int G1_register[10], G2_register[10];
-    unsigned int feedback1, feedback2;
+    bool G1[1023];
+    bool G2[1023];
+    bool G1_register[10], G2_register[10];
+    bool feedback1, feedback2;
+    bool aux;
     unsigned int lcv, lcv2;
     unsigned int delay;
     signed int prn_idx;
@@ -58,7 +59,7 @@ void gps_l1_ca_code_gen_complex(std::complex<float>* _dest, signed int _prn, uns
     }
     else
     {
-    	prn_idx = _prn-1;
+    	prn_idx = _prn - 1;
     }
 
     /* A simple error check */
@@ -94,13 +95,18 @@ void gps_l1_ca_code_gen_complex(std::complex<float>* _dest, signed int _prn, uns
     delay = 1023 - delays[prn_idx];
     delay += _chip_shift;
     delay %= 1023;
+
     /* Generate PRN from G1 and G2 Registers */
     for(lcv = 0; lcv < 1023; lcv++)
         {
-            _dest[lcv] = std::complex<float>(G1[(lcv +  _chip_shift)%1023]^G2[delay], 0);
-            if(_dest[lcv].real() == 0.0) //javi
+            aux = G1[(lcv +  _chip_shift) % 1023]^G2[delay];
+            if(aux == true)
                 {
-                    _dest[lcv].real(-1.0);
+                    _dest[lcv] = std::complex<float>(1, 0);
+                }
+            else
+                {
+                    _dest[lcv] = std::complex<float>(-1, 0);
                 }
             delay++;
             delay %= 1023;
@@ -108,6 +114,7 @@ void gps_l1_ca_code_gen_complex(std::complex<float>* _dest, signed int _prn, uns
 }
 
 
+
 /*
  *  Generates complex GPS L1 C/A code for the desired SV ID and sampled to specific sampling frequency
  */
diff --git a/src/tests/arithmetic/code_generation_test.cc b/src/tests/arithmetic/code_generation_test.cc
new file mode 100644
index 000000000..0813cadb4
--- /dev/null
+++ b/src/tests/arithmetic/code_generation_test.cc
@@ -0,0 +1,80 @@
+/*!
+ * \file code_generation_test.cc
+ * \brief  This file implements tests for the generation of complex exponentials.
+ * \author Carles Fernandez-Prades, 2014. cfernandez(at)cttc.es
+ *
+ *
+ * -------------------------------------------------------------------------
+ *
+ * Copyright (C) 2010-2015  (see AUTHORS file for a list of contributors)
+ *
+ * GNSS-SDR is a software defined Global Navigation
+ *          Satellite Systems receiver
+ *
+ * This file is part of GNSS-SDR.
+ *
+ * GNSS-SDR is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GNSS-SDR is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * -------------------------------------------------------------------------
+ */
+
+
+#include <complex>
+#include <ctime>
+#include "gps_sdr_signal_processing.h"
+
+
+
+TEST(CodeGenGPSL1_Test, CodeGeneration)
+{
+    std::complex<float>* _dest = new std::complex<float>[1023];
+    signed int _prn = 1;
+    unsigned int _chip_shift = 4;
+
+    int iterations = 100;
+
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    long long int begin = tv.tv_sec * 1000000 + tv.tv_usec;
+
+    for(int i = 0; i < iterations; i++)
+        {
+            gps_l1_ca_code_gen_complex( _dest,  _prn,  _chip_shift);
+        }
+
+    gettimeofday(&tv, NULL);
+    long long int end = tv.tv_sec * 1000000 + tv.tv_usec;
+    ASSERT_LE(0, end - begin);
+    std::cout << "Generation completed in " << (end - begin) << " microseconds" << std::endl;
+    delete[] _dest;
+
+
+    /* std::complex<float>* _dest2 = new std::complex<float>[1023];gettimeofday(&tv, NULL);
+    long long int begin2 = tv.tv_sec * 1000000 + tv.tv_usec;
+
+    for(int i = 0; i < iterations; i++)
+        {
+            gps_l1_ca_code_gen_complex2( _dest2,  _prn,  _chip_shift);
+        }
+
+    gettimeofday(&tv, NULL);
+    long long int end2 = tv.tv_sec * 1000000 + tv.tv_usec;
+    std::cout << "Generation 2 completed in " << (end2 - begin2) << " microseconds" << std::endl;
+
+    for (int j=0; j<1023;j++)
+        {
+            if(_dest[j] != _dest2[j]) std::cout << "Error!" << std::endl;
+        }
+    delete _dest2; */
+}
diff --git a/src/tests/test_main.cc b/src/tests/test_main.cc
index ffa7e2064..7e523d89f 100644
--- a/src/tests/test_main.cc
+++ b/src/tests/test_main.cc
@@ -70,6 +70,7 @@ DECLARE_string(log_dir);
 #include "arithmetic/conjugate_test.cc"
 #include "arithmetic/magnitude_squared_test.cc"
 #include "arithmetic/multiply_test.cc"
+#include "arithmetic/code_generation_test.cc"
 #include "configuration/file_configuration_test.cc"
 #include "configuration/in_memory_configuration_test.cc"
 #include "control_thread/control_message_factory_test.cc"