/* -*- c++ -*- */
/*
- * Copyright 2003,2005 Free Software Foundation, Inc.
+ * Copyright 2003,2005,2008 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
#ifndef _GR_MATH_H_
#define _GR_MATH_H_
+#include <gr_complex.h>
+
+static inline bool
+gr_is_power_of_2(long x)
+{
+ return x != 0 && (x & (x-1)) == 0;
+}
+
long gr_gcd (long m, long n);
// returns a non-zero value if value is "not-a-number" (NaN), and 0 otherwise
/*!
* \brief Fast arc tangent using table lookup and linear interpolation
+ * \ingroup misc
*
* \param y component of input vector
* \param x component of input vector
*/
float gr_fast_atan2f(float y, float x);
+static inline float gr_fast_atan2f(gr_complex z)
+{
+ return gr_fast_atan2f(z.imag(), z.real());
+}
+
+/* This bounds x by +/- clip without a branch */
+static inline float gr_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 gr_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 gr_binary_slicer(float x)
+{
+ if(x >= 0)
+ return 1;
+ else
+ return 0;
+}
+
+static inline unsigned int gr_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 gr_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 gr_quad_45deg_slicer(gr_complex x)
+{
+ return gr_quad_45deg_slicer(x.real(), x.imag());
+}
+
+static inline unsigned int gr_quad_0deg_slicer(gr_complex x)
+{
+ return gr_quad_0deg_slicer(x.real(), x.imag());
+}
+
+// Branchless Slicer Functions
+static inline unsigned int gr_branchless_binary_slicer(float x)
+{
+ return (x >= 0);
+}
+
+static inline unsigned int gr_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 gr_branchless_quad_0deg_slicer(gr_complex x)
+{
+ return gr_branchless_quad_0deg_slicer(x.real(), x.imag());
+}
+
+static inline unsigned int gr_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 gr_branchless_quad_45deg_slicer(gr_complex x)
+{
+ return gr_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
+gr_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
+gr_p2_round_up(size_t x, size_t pow2)
+{
+ return gr_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
+gr_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
+gr_p2_modulo_neg(size_t x, size_t pow2)
+{
+ return pow2 - gr_p2_modulo(x, pow2);
+}
+
#endif /* _GR_MATH_H_ */