From f3e2e07201c50033bf6c9d0c6a6f068557b4f17f Mon Sep 17 00:00:00 2001
From: Tom Rondeau <trondeau@vt.edu>
Date: Wed, 17 Apr 2013 13:43:52 -0400
Subject: runtime: converting runtime core to gr namespace, gnuradio include
dir.
---
gnuradio-runtime/include/gnuradio/math.h | 226 +++++++++++++++++++++++++++++++
1 file changed, 226 insertions(+)
create mode 100644 gnuradio-runtime/include/gnuradio/math.h
(limited to 'gnuradio-runtime/include/gnuradio/math.h')
diff --git a/gnuradio-runtime/include/gnuradio/math.h b/gnuradio-runtime/include/gnuradio/math.h
new file mode 100644
index 0000000000..ec4cfb014f
--- /dev/null
+++ b/gnuradio-runtime/include/gnuradio/math.h
@@ -0,0 +1,226 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2003,2005,2008,2013 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio 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, or (at your option)
+ * any later version.
+ *
+ * GNU Radio 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 GNU Radio; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+/*
+ * mathematical odds and ends.
+ */
+
+#ifndef _GR_MATH_H_
+#define _GR_MATH_H_
+
+#include <gnuradio/api.h>
+#include <gnuradio/gr_complex.h>
+
+namespace gr {
+
+ static inline bool
+ is_power_of_2(long x)
+ {
+ return x != 0 && (x & (x-1)) == 0;
+ }
+
+ /*!
+ * \brief Fast arc tangent using table lookup and linear interpolation
+ * \ingroup misc
+ *
+ * \param y component of input vector
+ * \param x component of input vector
+ * \returns float angle angle of vector (x, y) in radians
+ *
+ * This function calculates the angle of the vector (x,y) based on a
+ * table lookup and linear interpolation. The table uses a 256 point
+ * table covering -45 to +45 degrees and uses symetry to determine
+ * the final angle value in the range of -180 to 180 degrees. Note
+ * that this function uses the small angle approximation for values
+ * close to zero. This routine calculates the arc tangent with an
+ * average error of +/- 0.045 degrees.
+ */
+ GR_RUNTIME_API float fast_atan2f(float y, float x);
+
+ static inline float
+ fast_atan2f(gr_complex z)
+ {
+ return fast_atan2f(z.imag(), z.real());
+ }
+
+ /* This bounds x by +/- clip without a branch */
+ static inline float
+ branchless_clip(float x, float clip)
+ {
+ float x1 = fabsf(x+clip);
+ float x2 = fabsf(x-clip);
+ x1 -= x2;
+ return 0.5*x1;
+ }
+
+ static inline float
+ clip(float x, float clip)
+ {
+ float y = x;
+ if(x > clip)
+ y = clip;
+ else if(x < -clip)
+ y = -clip;
+ return y;
+ }
+
+ // Slicer Functions
+ static inline unsigned int
+ binary_slicer(float x)
+ {
+ if(x >= 0)
+ return 1;
+ else
+ return 0;
+ }
+
+ static inline unsigned int
+ quad_45deg_slicer(float r, float i)
+ {
+ unsigned int ret = 0;
+ if((r >= 0) && (i >= 0))
+ ret = 0;
+ else if((r < 0) && (i >= 0))
+ ret = 1;
+ else if((r < 0) && (i < 0))
+ ret = 2;
+ else
+ ret = 3;
+ return ret;
+ }
+
+ static inline unsigned int
+ quad_0deg_slicer(float r, float i)
+ {
+ unsigned int ret = 0;
+ if(fabsf(r) > fabsf(i)) {
+ if(r > 0)
+ ret = 0;
+ else
+ ret = 2;
+ }
+ else {
+ if(i > 0)
+ ret = 1;
+ else
+ ret = 3;
+ }
+
+ return ret;
+ }
+
+ static inline unsigned int
+ quad_45deg_slicer(gr_complex x)
+ {
+ return quad_45deg_slicer(x.real(), x.imag());
+ }
+
+ static inline unsigned int
+ quad_0deg_slicer(gr_complex x)
+ {
+ return quad_0deg_slicer(x.real(), x.imag());
+ }
+
+ // Branchless Slicer Functions
+ static inline unsigned int
+ branchless_binary_slicer(float x)
+ {
+ return (x >= 0);
+ }
+
+ static inline unsigned int
+ branchless_quad_0deg_slicer(float r, float i)
+ {
+ unsigned int ret = 0;
+ ret = (fabsf(r) > fabsf(i)) * (((r < 0) << 0x1)); // either 0 (00) or 2 (10)
+ ret |= (fabsf(i) > fabsf(r)) * (((i < 0) << 0x1) | 0x1); // either 1 (01) or 3 (11)
+
+ return ret;
+ }
+
+ static inline unsigned int
+ branchless_quad_0deg_slicer(gr_complex x)
+ {
+ return branchless_quad_0deg_slicer(x.real(), x.imag());
+ }
+
+ static inline unsigned int
+ branchless_quad_45deg_slicer(float r, float i)
+ {
+ char ret = (r <= 0);
+ ret |= ((i <= 0) << 1);
+ return (ret ^ ((ret & 0x2) >> 0x1));
+ }
+
+ static inline unsigned int
+ branchless_quad_45deg_slicer(gr_complex x)
+ {
+ return branchless_quad_45deg_slicer(x.real(), x.imag());
+ }
+
+ /*!
+ * \param x any value
+ * \param pow2 must be a power of 2
+ * \returns \p x rounded down to a multiple of \p pow2.
+ */
+ static inline size_t
+ p2_round_down(size_t x, size_t pow2)
+ {
+ return x & -pow2;
+ }
+
+ /*!
+ * \param x any value
+ * \param pow2 must be a power of 2
+ * \returns \p x rounded up to a multiple of \p pow2.
+ */
+ static inline size_t
+ p2_round_up(size_t x, size_t pow2)
+ {
+ return p2_round_down(x + pow2 - 1, pow2);
+ }
+
+ /*!
+ * \param x any value
+ * \param pow2 must be a power of 2
+ * \returns \p x modulo \p pow2.
+ */
+ static inline size_t
+ p2_modulo(size_t x, size_t pow2)
+ {
+ return x & (pow2 - 1);
+ }
+
+ /*!
+ * \param x any value
+ * \param pow2 must be a power of 2
+ * \returns \p pow2 - (\p x modulo \p pow2).
+ */
+ static inline size_t
+ p2_modulo_neg(size_t x, size_t pow2)
+ {
+ return pow2 - p2_modulo(x, pow2);
+ }
+
+} /* namespace gr */
+
+#endif /* _GR_MATH_H_ */
--
cgit v1.2.3