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/*
dsp/util.h
Copyright 2002-12 Tim Goetze <tim@quitte.de>
http://quitte.de/dsp/
Common math utility functions.
*/
/*
This program 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.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA or point your web browser to http://www.gnu.org.
*/
#ifndef _DSP_UTIL_H_
#define _DSP_UTIL_H_
namespace DSP {
inline float pow2 (float x) { return x * x; }
inline float pow3 (float x) { return x * pow2(x); }
inline float pow4 (float x) { return pow2 (pow2(x)); }
inline float pow5 (float x) { return x * pow4(x); }
inline float pow6 (float x) { return pow3 (pow2(x)); }
inline float pow7 (float x) { return x * (pow6 (x)); }
inline float pow8 (float x) { return pow2 (pow4 (x)); }
inline float
sgn (float x)
{
union { float f; uint32 i; } u;
u.f = x;
u.i &= 0x80000000;
u.i |= 0x3F800000;
return u.f;
}
inline bool
isprime (int v)
{
if (v <= 3)
return true;
if (!(v & 1))
return false;
// NOTE(rryan): float cast added for MSVC.
for (int i = 3; i < (int) sqrt ((float)v) + 1; i += 2)
if ((v % i) == 0)
return false;
return true;
}
} /* namespace DSP */
#endif /* _DSP_UTIL_H_ */
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