From ea162bacad0e6fce379b9ae2c9155ccae4a60f77 Mon Sep 17 00:00:00 2001
From: Cillian O'Driscoll <cillian.odriscoll@gmail.com>
Date: Wed, 2 Dec 2015 14:05:34 +0000
Subject: [PATCH] Added fxpt64

---
 src/algorithms/tracking/libs/CMakeLists.txt |  3 +-
 src/algorithms/tracking/libs/fxpt64.cc      | 50 +++++++++++++++++++++
 src/algorithms/tracking/libs/fxpt64.h       | 41 +++++++++++++++++
 3 files changed, 93 insertions(+), 1 deletion(-)
 create mode 100644 src/algorithms/tracking/libs/fxpt64.cc
 create mode 100644 src/algorithms/tracking/libs/fxpt64.h

diff --git a/src/algorithms/tracking/libs/CMakeLists.txt b/src/algorithms/tracking/libs/CMakeLists.txt
index 505c62685..3abcd1e80 100644
--- a/src/algorithms/tracking/libs/CMakeLists.txt
+++ b/src/algorithms/tracking/libs/CMakeLists.txt
@@ -30,9 +30,10 @@ if(ENABLE_CUDA)
 endif(ENABLE_CUDA)
 
 
-set(TRACKING_LIB_SOURCES   
+set(TRACKING_LIB_SOURCES
      correlator.cc
      cpu_multicorrelator.cc
+     fxpt64.cc
      lock_detectors.cc
      tcp_communication.cc
      tcp_packet_data.cc
diff --git a/src/algorithms/tracking/libs/fxpt64.cc b/src/algorithms/tracking/libs/fxpt64.cc
new file mode 100644
index 000000000..f4ee86e94
--- /dev/null
+++ b/src/algorithms/tracking/libs/fxpt64.cc
@@ -0,0 +1,50 @@
+/*!
+ * \file fxpt64.cc
+ * \brief Utility functions for fixed point 64 bit arithmetic
+ * \authors <ul>
+ *          <li> Cillian O'Driscoll, 2015. cillian.odriscoll(at)gmail.com
+ *          </ul>
+ *
+ *
+ * -------------------------------------------------------------------------
+ *
+ * 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 "fxpt64.h"
+#include <cmath>
+
+int64_t double_to_fxpt64( double in, unsigned int frac_len )
+{
+    int64_t out = static_cast< int64_t >( in * std::pow(2.0, frac_len) );
+
+    return out;
+}
+
+double fxpt64_to_double( int64_t in, unsigned int frac_len )
+{
+    double out = static_cast< double >( in ) * std::pow( 2.0, -static_cast<double>(frac_len) );
+
+    return out;
+}
+
diff --git a/src/algorithms/tracking/libs/fxpt64.h b/src/algorithms/tracking/libs/fxpt64.h
new file mode 100644
index 000000000..075af2232
--- /dev/null
+++ b/src/algorithms/tracking/libs/fxpt64.h
@@ -0,0 +1,41 @@
+/*!
+ * \file fxpt64.h
+ * \brief Utility functions for fixed point 64 bit arithmetic
+ * \authors <ul>
+ *          <li> Cillian O'Driscoll, 2015. cillian.odriscoll(at)gmail.com
+ *          </ul>
+ *
+ *
+ * -------------------------------------------------------------------------
+ *
+ * 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/>.
+ *
+ * -------------------------------------------------------------------------
+ */
+
+#ifndef GNSS_SDR_FXPT64_H_
+#define GNSS_SDR_FXPT64_H_
+#include <cstdint>
+
+int64_t double_to_fxpt64( double in, unsigned int frac_len = 32 );
+double fxpt64_to_double( int64_t in, unsigned int frac_len = 32 );
+
+#endif