sincos.h

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// This file's extension implies that it's C, but it's really -*- C++ -*-.
 
/*
  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
*/
 
// $Id: sincos.h,v 1.1 2008-11-24 04:34:07 ssnyder Exp $
 
#ifndef CXXUTILS_SINCOS_H
#define CXXUTILS_SINCOS_H
 
 
#include <cmath>
 
 
namespace CxxUtils {
 
 
struct sincos
{
  sincos (double x)
#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
  // Inline assembly version.  Uses x87 FPU.
  { __asm __volatile__ ("fsincos\n\t" : "=t" (cs), "=u" (sn) : "0" (x)); }
#elif defined(__USE_GNU)
  // Version using the GNU sincos() function.
  { ::sincos(x, &sn, &cs); }
#else
  // Generic version.
  : sn (std::sin (x)), cs (std::cos (x)) {}
#endif
 
  double sn;
 
  double cs;
 
  double apply (double a, double b) const { return a*sn + b*cs; }
 
  double apply2 (double a, double b, double c) const
  { return a*sn*sn + b*sn*cs + c*cs*cs; }
};
 
 
} // namespace CxxUtils
 
 
#endif //not CXXUTILS_SINCOS_H