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      1 // This file is part of Eigen, a lightweight C++ template library
      2 // for linear algebra.
      3 //
      4 // Copyright (C) 2006-2010 Benoit Jacob <jacob.benoit.1 (at) gmail.com>
      5 //
      6 // This Source Code Form is subject to the terms of the Mozilla
      7 // Public License v. 2.0. If a copy of the MPL was not distributed
      8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
      9 
     10 #ifndef EIGEN_MATHFUNCTIONS_H
     11 #define EIGEN_MATHFUNCTIONS_H
     12 
     13 // source: http://www.geom.uiuc.edu/~huberty/math5337/groupe/digits.html
     14 // TODO this should better be moved to NumTraits
     15 #define EIGEN_PI 3.141592653589793238462643383279502884197169399375105820974944592307816406L
     16 
     17 
     18 namespace Eigen {
     19 
     20 // On WINCE, std::abs is defined for int only, so let's defined our own overloads:
     21 // This issue has been confirmed with MSVC 2008 only, but the issue might exist for more recent versions too.
     22 #if EIGEN_OS_WINCE && EIGEN_COMP_MSVC && EIGEN_COMP_MSVC<=1500
     23 long        abs(long        x) { return (labs(x));  }
     24 double      abs(double      x) { return (fabs(x));  }
     25 float       abs(float       x) { return (fabsf(x)); }
     26 long double abs(long double x) { return (fabsl(x)); }
     27 #endif
     28 
     29 namespace internal {
     30 
     31 /** \internal \class global_math_functions_filtering_base
     32   *
     33   * What it does:
     34   * Defines a typedef 'type' as follows:
     35   * - if type T has a member typedef Eigen_BaseClassForSpecializationOfGlobalMathFuncImpl, then
     36   *   global_math_functions_filtering_base<T>::type is a typedef for it.
     37   * - otherwise, global_math_functions_filtering_base<T>::type is a typedef for T.
     38   *
     39   * How it's used:
     40   * To allow to defined the global math functions (like sin...) in certain cases, like the Array expressions.
     41   * When you do sin(array1+array2), the object array1+array2 has a complicated expression type, all what you want to know
     42   * is that it inherits ArrayBase. So we implement a partial specialization of sin_impl for ArrayBase<Derived>.
     43   * So we must make sure to use sin_impl<ArrayBase<Derived> > and not sin_impl<Derived>, otherwise our partial specialization
     44   * won't be used. How does sin know that? That's exactly what global_math_functions_filtering_base tells it.
     45   *
     46   * How it's implemented:
     47   * SFINAE in the style of enable_if. Highly susceptible of breaking compilers. With GCC, it sure does work, but if you replace
     48   * the typename dummy by an integer template parameter, it doesn't work anymore!
     49   */
     50 
     51 template<typename T, typename dummy = void>
     52 struct global_math_functions_filtering_base
     53 {
     54   typedef T type;
     55 };
     56 
     57 template<typename T> struct always_void { typedef void type; };
     58 
     59 template<typename T>
     60 struct global_math_functions_filtering_base
     61   <T,
     62    typename always_void<typename T::Eigen_BaseClassForSpecializationOfGlobalMathFuncImpl>::type
     63   >
     64 {
     65   typedef typename T::Eigen_BaseClassForSpecializationOfGlobalMathFuncImpl type;
     66 };
     67 
     68 #define EIGEN_MATHFUNC_IMPL(func, scalar) Eigen::internal::func##_impl<typename Eigen::internal::global_math_functions_filtering_base<scalar>::type>
     69 #define EIGEN_MATHFUNC_RETVAL(func, scalar) typename Eigen::internal::func##_retval<typename Eigen::internal::global_math_functions_filtering_base<scalar>::type>::type
     70 
     71 /****************************************************************************
     72 * Implementation of real                                                 *
     73 ****************************************************************************/
     74 
     75 template<typename Scalar, bool IsComplex = NumTraits<Scalar>::IsComplex>
     76 struct real_default_impl
     77 {
     78   typedef typename NumTraits<Scalar>::Real RealScalar;
     79   EIGEN_DEVICE_FUNC
     80   static inline RealScalar run(const Scalar& x)
     81   {
     82     return x;
     83   }
     84 };
     85 
     86 template<typename Scalar>
     87 struct real_default_impl<Scalar,true>
     88 {
     89   typedef typename NumTraits<Scalar>::Real RealScalar;
     90   EIGEN_DEVICE_FUNC
     91   static inline RealScalar run(const Scalar& x)
     92   {
     93     using std::real;
     94     return real(x);
     95   }
     96 };
     97 
     98 template<typename Scalar> struct real_impl : real_default_impl<Scalar> {};
     99 
    100 #ifdef __CUDA_ARCH__
    101 template<typename T>
    102 struct real_impl<std::complex<T> >
    103 {
    104   typedef T RealScalar;
    105   EIGEN_DEVICE_FUNC
    106   static inline T run(const std::complex<T>& x)
    107   {
    108     return x.real();
    109   }
    110 };
    111 #endif
    112 
    113 template<typename Scalar>
    114 struct real_retval
    115 {
    116   typedef typename NumTraits<Scalar>::Real type;
    117 };
    118 
    119 /****************************************************************************
    120 * Implementation of imag                                                 *
    121 ****************************************************************************/
    122 
    123 template<typename Scalar, bool IsComplex = NumTraits<Scalar>::IsComplex>
    124 struct imag_default_impl
    125 {
    126   typedef typename NumTraits<Scalar>::Real RealScalar;
    127   EIGEN_DEVICE_FUNC
    128   static inline RealScalar run(const Scalar&)
    129   {
    130     return RealScalar(0);
    131   }
    132 };
    133 
    134 template<typename Scalar>
    135 struct imag_default_impl<Scalar,true>
    136 {
    137   typedef typename NumTraits<Scalar>::Real RealScalar;
    138   EIGEN_DEVICE_FUNC
    139   static inline RealScalar run(const Scalar& x)
    140   {
    141     using std::imag;
    142     return imag(x);
    143   }
    144 };
    145 
    146 template<typename Scalar> struct imag_impl : imag_default_impl<Scalar> {};
    147 
    148 #ifdef __CUDA_ARCH__
    149 template<typename T>
    150 struct imag_impl<std::complex<T> >
    151 {
    152   typedef T RealScalar;
    153   EIGEN_DEVICE_FUNC
    154   static inline T run(const std::complex<T>& x)
    155   {
    156     return x.imag();
    157   }
    158 };
    159 #endif
    160 
    161 template<typename Scalar>
    162 struct imag_retval
    163 {
    164   typedef typename NumTraits<Scalar>::Real type;
    165 };
    166 
    167 /****************************************************************************
    168 * Implementation of real_ref                                             *
    169 ****************************************************************************/
    170 
    171 template<typename Scalar>
    172 struct real_ref_impl
    173 {
    174   typedef typename NumTraits<Scalar>::Real RealScalar;
    175   EIGEN_DEVICE_FUNC
    176   static inline RealScalar& run(Scalar& x)
    177   {
    178     return reinterpret_cast<RealScalar*>(&x)[0];
    179   }
    180   EIGEN_DEVICE_FUNC
    181   static inline const RealScalar& run(const Scalar& x)
    182   {
    183     return reinterpret_cast<const RealScalar*>(&x)[0];
    184   }
    185 };
    186 
    187 template<typename Scalar>
    188 struct real_ref_retval
    189 {
    190   typedef typename NumTraits<Scalar>::Real & type;
    191 };
    192 
    193 /****************************************************************************
    194 * Implementation of imag_ref                                             *
    195 ****************************************************************************/
    196 
    197 template<typename Scalar, bool IsComplex>
    198 struct imag_ref_default_impl
    199 {
    200   typedef typename NumTraits<Scalar>::Real RealScalar;
    201   EIGEN_DEVICE_FUNC
    202   static inline RealScalar& run(Scalar& x)
    203   {
    204     return reinterpret_cast<RealScalar*>(&x)[1];
    205   }
    206   EIGEN_DEVICE_FUNC
    207   static inline const RealScalar& run(const Scalar& x)
    208   {
    209     return reinterpret_cast<RealScalar*>(&x)[1];
    210   }
    211 };
    212 
    213 template<typename Scalar>
    214 struct imag_ref_default_impl<Scalar, false>
    215 {
    216   EIGEN_DEVICE_FUNC
    217   static inline Scalar run(Scalar&)
    218   {
    219     return Scalar(0);
    220   }
    221   EIGEN_DEVICE_FUNC
    222   static inline const Scalar run(const Scalar&)
    223   {
    224     return Scalar(0);
    225   }
    226 };
    227 
    228 template<typename Scalar>
    229 struct imag_ref_impl : imag_ref_default_impl<Scalar, NumTraits<Scalar>::IsComplex> {};
    230 
    231 template<typename Scalar>
    232 struct imag_ref_retval
    233 {
    234   typedef typename NumTraits<Scalar>::Real & type;
    235 };
    236 
    237 /****************************************************************************
    238 * Implementation of conj                                                 *
    239 ****************************************************************************/
    240 
    241 template<typename Scalar, bool IsComplex = NumTraits<Scalar>::IsComplex>
    242 struct conj_impl
    243 {
    244   EIGEN_DEVICE_FUNC
    245   static inline Scalar run(const Scalar& x)
    246   {
    247     return x;
    248   }
    249 };
    250 
    251 template<typename Scalar>
    252 struct conj_impl<Scalar,true>
    253 {
    254   EIGEN_DEVICE_FUNC
    255   static inline Scalar run(const Scalar& x)
    256   {
    257     using std::conj;
    258     return conj(x);
    259   }
    260 };
    261 
    262 template<typename Scalar>
    263 struct conj_retval
    264 {
    265   typedef Scalar type;
    266 };
    267 
    268 /****************************************************************************
    269 * Implementation of abs2                                                 *
    270 ****************************************************************************/
    271 
    272 template<typename Scalar,bool IsComplex>
    273 struct abs2_impl_default
    274 {
    275   typedef typename NumTraits<Scalar>::Real RealScalar;
    276   EIGEN_DEVICE_FUNC
    277   static inline RealScalar run(const Scalar& x)
    278   {
    279     return x*x;
    280   }
    281 };
    282 
    283 template<typename Scalar>
    284 struct abs2_impl_default<Scalar, true> // IsComplex
    285 {
    286   typedef typename NumTraits<Scalar>::Real RealScalar;
    287   EIGEN_DEVICE_FUNC
    288   static inline RealScalar run(const Scalar& x)
    289   {
    290     return real(x)*real(x) + imag(x)*imag(x);
    291   }
    292 };
    293 
    294 template<typename Scalar>
    295 struct abs2_impl
    296 {
    297   typedef typename NumTraits<Scalar>::Real RealScalar;
    298   EIGEN_DEVICE_FUNC
    299   static inline RealScalar run(const Scalar& x)
    300   {
    301     return abs2_impl_default<Scalar,NumTraits<Scalar>::IsComplex>::run(x);
    302   }
    303 };
    304 
    305 template<typename Scalar>
    306 struct abs2_retval
    307 {
    308   typedef typename NumTraits<Scalar>::Real type;
    309 };
    310 
    311 /****************************************************************************
    312 * Implementation of norm1                                                *
    313 ****************************************************************************/
    314 
    315 template<typename Scalar, bool IsComplex>
    316 struct norm1_default_impl
    317 {
    318   typedef typename NumTraits<Scalar>::Real RealScalar;
    319   EIGEN_DEVICE_FUNC
    320   static inline RealScalar run(const Scalar& x)
    321   {
    322     EIGEN_USING_STD_MATH(abs);
    323     return abs(real(x)) + abs(imag(x));
    324   }
    325 };
    326 
    327 template<typename Scalar>
    328 struct norm1_default_impl<Scalar, false>
    329 {
    330   EIGEN_DEVICE_FUNC
    331   static inline Scalar run(const Scalar& x)
    332   {
    333     EIGEN_USING_STD_MATH(abs);
    334     return abs(x);
    335   }
    336 };
    337 
    338 template<typename Scalar>
    339 struct norm1_impl : norm1_default_impl<Scalar, NumTraits<Scalar>::IsComplex> {};
    340 
    341 template<typename Scalar>
    342 struct norm1_retval
    343 {
    344   typedef typename NumTraits<Scalar>::Real type;
    345 };
    346 
    347 /****************************************************************************
    348 * Implementation of hypot                                                *
    349 ****************************************************************************/
    350 
    351 template<typename Scalar>
    352 struct hypot_impl
    353 {
    354   typedef typename NumTraits<Scalar>::Real RealScalar;
    355   static inline RealScalar run(const Scalar& x, const Scalar& y)
    356   {
    357     EIGEN_USING_STD_MATH(abs);
    358     EIGEN_USING_STD_MATH(sqrt);
    359     RealScalar _x = abs(x);
    360     RealScalar _y = abs(y);
    361     Scalar p, qp;
    362     if(_x>_y)
    363     {
    364       p = _x;
    365       qp = _y / p;
    366     }
    367     else
    368     {
    369       p = _y;
    370       qp = _x / p;
    371     }
    372     if(p==RealScalar(0)) return RealScalar(0);
    373     return p * sqrt(RealScalar(1) + qp*qp);
    374   }
    375 };
    376 
    377 template<typename Scalar>
    378 struct hypot_retval
    379 {
    380   typedef typename NumTraits<Scalar>::Real type;
    381 };
    382 
    383 /****************************************************************************
    384 * Implementation of cast                                                 *
    385 ****************************************************************************/
    386 
    387 template<typename OldType, typename NewType>
    388 struct cast_impl
    389 {
    390   EIGEN_DEVICE_FUNC
    391   static inline NewType run(const OldType& x)
    392   {
    393     return static_cast<NewType>(x);
    394   }
    395 };
    396 
    397 // here, for once, we're plainly returning NewType: we don't want cast to do weird things.
    398 
    399 template<typename OldType, typename NewType>
    400 EIGEN_DEVICE_FUNC
    401 inline NewType cast(const OldType& x)
    402 {
    403   return cast_impl<OldType, NewType>::run(x);
    404 }
    405 
    406 /****************************************************************************
    407 * Implementation of round                                                   *
    408 ****************************************************************************/
    409 
    410 #if EIGEN_HAS_CXX11_MATH
    411   template<typename Scalar>
    412   struct round_impl {
    413     static inline Scalar run(const Scalar& x)
    414     {
    415       EIGEN_STATIC_ASSERT((!NumTraits<Scalar>::IsComplex), NUMERIC_TYPE_MUST_BE_REAL)
    416       using std::round;
    417       return round(x);
    418     }
    419   };
    420 #else
    421   template<typename Scalar>
    422   struct round_impl
    423   {
    424     static inline Scalar run(const Scalar& x)
    425     {
    426       EIGEN_STATIC_ASSERT((!NumTraits<Scalar>::IsComplex), NUMERIC_TYPE_MUST_BE_REAL)
    427       EIGEN_USING_STD_MATH(floor);
    428       EIGEN_USING_STD_MATH(ceil);
    429       return (x > Scalar(0)) ? floor(x + Scalar(0.5)) : ceil(x - Scalar(0.5));
    430     }
    431   };
    432 #endif
    433 
    434 template<typename Scalar>
    435 struct round_retval
    436 {
    437   typedef Scalar type;
    438 };
    439 
    440 /****************************************************************************
    441 * Implementation of arg                                                     *
    442 ****************************************************************************/
    443 
    444 #if EIGEN_HAS_CXX11_MATH
    445   template<typename Scalar>
    446   struct arg_impl {
    447     static inline Scalar run(const Scalar& x)
    448     {
    449       EIGEN_USING_STD_MATH(arg);
    450       return arg(x);
    451     }
    452   };
    453 #else
    454   template<typename Scalar, bool IsComplex = NumTraits<Scalar>::IsComplex>
    455   struct arg_default_impl
    456   {
    457     typedef typename NumTraits<Scalar>::Real RealScalar;
    458     EIGEN_DEVICE_FUNC
    459     static inline RealScalar run(const Scalar& x)
    460     {
    461       return (x < Scalar(0)) ? Scalar(EIGEN_PI) : Scalar(0); }
    462   };
    463 
    464   template<typename Scalar>
    465   struct arg_default_impl<Scalar,true>
    466   {
    467     typedef typename NumTraits<Scalar>::Real RealScalar;
    468     EIGEN_DEVICE_FUNC
    469     static inline RealScalar run(const Scalar& x)
    470     {
    471       EIGEN_USING_STD_MATH(arg);
    472       return arg(x);
    473     }
    474   };
    475 
    476   template<typename Scalar> struct arg_impl : arg_default_impl<Scalar> {};
    477 #endif
    478 
    479 template<typename Scalar>
    480 struct arg_retval
    481 {
    482   typedef typename NumTraits<Scalar>::Real type;
    483 };
    484 
    485 /****************************************************************************
    486 * Implementation of log1p                                                   *
    487 ****************************************************************************/
    488 
    489 namespace std_fallback {
    490   // fallback log1p implementation in case there is no log1p(Scalar) function in namespace of Scalar,
    491   // or that there is no suitable std::log1p function available
    492   template<typename Scalar>
    493   EIGEN_DEVICE_FUNC inline Scalar log1p(const Scalar& x) {
    494     EIGEN_STATIC_ASSERT_NON_INTEGER(Scalar)
    495     typedef typename NumTraits<Scalar>::Real RealScalar;
    496     EIGEN_USING_STD_MATH(log);
    497     Scalar x1p = RealScalar(1) + x;
    498     return ( x1p == Scalar(1) ) ? x : x * ( log(x1p) / (x1p - RealScalar(1)) );
    499   }
    500 }
    501 
    502 template<typename Scalar>
    503 struct log1p_impl {
    504   static inline Scalar run(const Scalar& x)
    505   {
    506     EIGEN_STATIC_ASSERT_NON_INTEGER(Scalar)
    507     #if EIGEN_HAS_CXX11_MATH
    508     using std::log1p;
    509     #endif
    510     using std_fallback::log1p;
    511     return log1p(x);
    512   }
    513 };
    514 
    515 
    516 template<typename Scalar>
    517 struct log1p_retval
    518 {
    519   typedef Scalar type;
    520 };
    521 
    522 /****************************************************************************
    523 * Implementation of pow                                                  *
    524 ****************************************************************************/
    525 
    526 template<typename ScalarX,typename ScalarY, bool IsInteger = NumTraits<ScalarX>::IsInteger&&NumTraits<ScalarY>::IsInteger>
    527 struct pow_impl
    528 {
    529   //typedef Scalar retval;
    530   typedef typename ScalarBinaryOpTraits<ScalarX,ScalarY,internal::scalar_pow_op<ScalarX,ScalarY> >::ReturnType result_type;
    531   static EIGEN_DEVICE_FUNC inline result_type run(const ScalarX& x, const ScalarY& y)
    532   {
    533     EIGEN_USING_STD_MATH(pow);
    534     return pow(x, y);
    535   }
    536 };
    537 
    538 template<typename ScalarX,typename ScalarY>
    539 struct pow_impl<ScalarX,ScalarY, true>
    540 {
    541   typedef ScalarX result_type;
    542   static EIGEN_DEVICE_FUNC inline ScalarX run(ScalarX x, ScalarY y)
    543   {
    544     ScalarX res(1);
    545     eigen_assert(!NumTraits<ScalarY>::IsSigned || y >= 0);
    546     if(y & 1) res *= x;
    547     y >>= 1;
    548     while(y)
    549     {
    550       x *= x;
    551       if(y&1) res *= x;
    552       y >>= 1;
    553     }
    554     return res;
    555   }
    556 };
    557 
    558 /****************************************************************************
    559 * Implementation of random                                               *
    560 ****************************************************************************/
    561 
    562 template<typename Scalar,
    563          bool IsComplex,
    564          bool IsInteger>
    565 struct random_default_impl {};
    566 
    567 template<typename Scalar>
    568 struct random_impl : random_default_impl<Scalar, NumTraits<Scalar>::IsComplex, NumTraits<Scalar>::IsInteger> {};
    569 
    570 template<typename Scalar>
    571 struct random_retval
    572 {
    573   typedef Scalar type;
    574 };
    575 
    576 template<typename Scalar> inline EIGEN_MATHFUNC_RETVAL(random, Scalar) random(const Scalar& x, const Scalar& y);
    577 template<typename Scalar> inline EIGEN_MATHFUNC_RETVAL(random, Scalar) random();
    578 
    579 template<typename Scalar>
    580 struct random_default_impl<Scalar, false, false>
    581 {
    582   static inline Scalar run(const Scalar& x, const Scalar& y)
    583   {
    584     return x + (y-x) * Scalar(std::rand()) / Scalar(RAND_MAX);
    585   }
    586   static inline Scalar run()
    587   {
    588     return run(Scalar(NumTraits<Scalar>::IsSigned ? -1 : 0), Scalar(1));
    589   }
    590 };
    591 
    592 enum {
    593   meta_floor_log2_terminate,
    594   meta_floor_log2_move_up,
    595   meta_floor_log2_move_down,
    596   meta_floor_log2_bogus
    597 };
    598 
    599 template<unsigned int n, int lower, int upper> struct meta_floor_log2_selector
    600 {
    601   enum { middle = (lower + upper) / 2,
    602          value = (upper <= lower + 1) ? int(meta_floor_log2_terminate)
    603                : (n < (1 << middle)) ? int(meta_floor_log2_move_down)
    604                : (n==0) ? int(meta_floor_log2_bogus)
    605                : int(meta_floor_log2_move_up)
    606   };
    607 };
    608 
    609 template<unsigned int n,
    610          int lower = 0,
    611          int upper = sizeof(unsigned int) * CHAR_BIT - 1,
    612          int selector = meta_floor_log2_selector<n, lower, upper>::value>
    613 struct meta_floor_log2 {};
    614 
    615 template<unsigned int n, int lower, int upper>
    616 struct meta_floor_log2<n, lower, upper, meta_floor_log2_move_down>
    617 {
    618   enum { value = meta_floor_log2<n, lower, meta_floor_log2_selector<n, lower, upper>::middle>::value };
    619 };
    620 
    621 template<unsigned int n, int lower, int upper>
    622 struct meta_floor_log2<n, lower, upper, meta_floor_log2_move_up>
    623 {
    624   enum { value = meta_floor_log2<n, meta_floor_log2_selector<n, lower, upper>::middle, upper>::value };
    625 };
    626 
    627 template<unsigned int n, int lower, int upper>
    628 struct meta_floor_log2<n, lower, upper, meta_floor_log2_terminate>
    629 {
    630   enum { value = (n >= ((unsigned int)(1) << (lower+1))) ? lower+1 : lower };
    631 };
    632 
    633 template<unsigned int n, int lower, int upper>
    634 struct meta_floor_log2<n, lower, upper, meta_floor_log2_bogus>
    635 {
    636   // no value, error at compile time
    637 };
    638 
    639 template<typename Scalar>
    640 struct random_default_impl<Scalar, false, true>
    641 {
    642   static inline Scalar run(const Scalar& x, const Scalar& y)
    643   {
    644     typedef typename conditional<NumTraits<Scalar>::IsSigned,std::ptrdiff_t,std::size_t>::type ScalarX;
    645     if(y<x)
    646       return x;
    647     // the following difference might overflow on a 32 bits system,
    648     // but since y>=x the result converted to an unsigned long is still correct.
    649     std::size_t range = ScalarX(y)-ScalarX(x);
    650     std::size_t offset = 0;
    651     // rejection sampling
    652     std::size_t divisor = 1;
    653     std::size_t multiplier = 1;
    654     if(range<RAND_MAX) divisor = (std::size_t(RAND_MAX)+1)/(range+1);
    655     else               multiplier = 1 + range/(std::size_t(RAND_MAX)+1);
    656     do {
    657       offset = (std::size_t(std::rand()) * multiplier) / divisor;
    658     } while (offset > range);
    659     return Scalar(ScalarX(x) + offset);
    660   }
    661 
    662   static inline Scalar run()
    663   {
    664 #ifdef EIGEN_MAKING_DOCS
    665     return run(Scalar(NumTraits<Scalar>::IsSigned ? -10 : 0), Scalar(10));
    666 #else
    667     enum { rand_bits = meta_floor_log2<(unsigned int)(RAND_MAX)+1>::value,
    668            scalar_bits = sizeof(Scalar) * CHAR_BIT,
    669            shift = EIGEN_PLAIN_ENUM_MAX(0, int(rand_bits) - int(scalar_bits)),
    670            offset = NumTraits<Scalar>::IsSigned ? (1 << (EIGEN_PLAIN_ENUM_MIN(rand_bits,scalar_bits)-1)) : 0
    671     };
    672     return Scalar((std::rand() >> shift) - offset);
    673 #endif
    674   }
    675 };
    676 
    677 template<typename Scalar>
    678 struct random_default_impl<Scalar, true, false>
    679 {
    680   static inline Scalar run(const Scalar& x, const Scalar& y)
    681   {
    682     return Scalar(random(real(x), real(y)),
    683                   random(imag(x), imag(y)));
    684   }
    685   static inline Scalar run()
    686   {
    687     typedef typename NumTraits<Scalar>::Real RealScalar;
    688     return Scalar(random<RealScalar>(), random<RealScalar>());
    689   }
    690 };
    691 
    692 template<typename Scalar>
    693 inline EIGEN_MATHFUNC_RETVAL(random, Scalar) random(const Scalar& x, const Scalar& y)
    694 {
    695   return EIGEN_MATHFUNC_IMPL(random, Scalar)::run(x, y);
    696 }
    697 
    698 template<typename Scalar>
    699 inline EIGEN_MATHFUNC_RETVAL(random, Scalar) random()
    700 {
    701   return EIGEN_MATHFUNC_IMPL(random, Scalar)::run();
    702 }
    703 
    704 // Implementatin of is* functions
    705 
    706 // std::is* do not work with fast-math and gcc, std::is* are available on MSVC 2013 and newer, as well as in clang.
    707 #if (EIGEN_HAS_CXX11_MATH && !(EIGEN_COMP_GNUC_STRICT && __FINITE_MATH_ONLY__)) || (EIGEN_COMP_MSVC>=1800) || (EIGEN_COMP_CLANG)
    708 #define EIGEN_USE_STD_FPCLASSIFY 1
    709 #else
    710 #define EIGEN_USE_STD_FPCLASSIFY 0
    711 #endif
    712 
    713 template<typename T>
    714 EIGEN_DEVICE_FUNC
    715 typename internal::enable_if<internal::is_integral<T>::value,bool>::type
    716 isnan_impl(const T&) { return false; }
    717 
    718 template<typename T>
    719 EIGEN_DEVICE_FUNC
    720 typename internal::enable_if<internal::is_integral<T>::value,bool>::type
    721 isinf_impl(const T&) { return false; }
    722 
    723 template<typename T>
    724 EIGEN_DEVICE_FUNC
    725 typename internal::enable_if<internal::is_integral<T>::value,bool>::type
    726 isfinite_impl(const T&) { return true; }
    727 
    728 template<typename T>
    729 EIGEN_DEVICE_FUNC
    730 typename internal::enable_if<(!internal::is_integral<T>::value)&&(!NumTraits<T>::IsComplex),bool>::type
    731 isfinite_impl(const T& x)
    732 {
    733   #ifdef __CUDA_ARCH__
    734     return (::isfinite)(x);
    735   #elif EIGEN_USE_STD_FPCLASSIFY
    736     using std::isfinite;
    737     return isfinite EIGEN_NOT_A_MACRO (x);
    738   #else
    739     return x<=NumTraits<T>::highest() && x>=NumTraits<T>::lowest();
    740   #endif
    741 }
    742 
    743 template<typename T>
    744 EIGEN_DEVICE_FUNC
    745 typename internal::enable_if<(!internal::is_integral<T>::value)&&(!NumTraits<T>::IsComplex),bool>::type
    746 isinf_impl(const T& x)
    747 {
    748   #ifdef __CUDA_ARCH__
    749     return (::isinf)(x);
    750   #elif EIGEN_USE_STD_FPCLASSIFY
    751     using std::isinf;
    752     return isinf EIGEN_NOT_A_MACRO (x);
    753   #else
    754     return x>NumTraits<T>::highest() || x<NumTraits<T>::lowest();
    755   #endif
    756 }
    757 
    758 template<typename T>
    759 EIGEN_DEVICE_FUNC
    760 typename internal::enable_if<(!internal::is_integral<T>::value)&&(!NumTraits<T>::IsComplex),bool>::type
    761 isnan_impl(const T& x)
    762 {
    763   #ifdef __CUDA_ARCH__
    764     return (::isnan)(x);
    765   #elif EIGEN_USE_STD_FPCLASSIFY
    766     using std::isnan;
    767     return isnan EIGEN_NOT_A_MACRO (x);
    768   #else
    769     return x != x;
    770   #endif
    771 }
    772 
    773 #if (!EIGEN_USE_STD_FPCLASSIFY)
    774 
    775 #if EIGEN_COMP_MSVC
    776 
    777 template<typename T> EIGEN_DEVICE_FUNC bool isinf_msvc_helper(T x)
    778 {
    779   return _fpclass(x)==_FPCLASS_NINF || _fpclass(x)==_FPCLASS_PINF;
    780 }
    781 
    782 //MSVC defines a _isnan builtin function, but for double only
    783 EIGEN_DEVICE_FUNC inline bool isnan_impl(const long double& x) { return _isnan(x)!=0; }
    784 EIGEN_DEVICE_FUNC inline bool isnan_impl(const double& x)      { return _isnan(x)!=0; }
    785 EIGEN_DEVICE_FUNC inline bool isnan_impl(const float& x)       { return _isnan(x)!=0; }
    786 
    787 EIGEN_DEVICE_FUNC inline bool isinf_impl(const long double& x) { return isinf_msvc_helper(x); }
    788 EIGEN_DEVICE_FUNC inline bool isinf_impl(const double& x)      { return isinf_msvc_helper(x); }
    789 EIGEN_DEVICE_FUNC inline bool isinf_impl(const float& x)       { return isinf_msvc_helper(x); }
    790 
    791 #elif (defined __FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ && EIGEN_COMP_GNUC)
    792 
    793 #if EIGEN_GNUC_AT_LEAST(5,0)
    794   #define EIGEN_TMP_NOOPT_ATTRIB EIGEN_DEVICE_FUNC inline __attribute__((optimize("no-finite-math-only")))
    795 #else
    796   // NOTE the inline qualifier and noinline attribute are both needed: the former is to avoid linking issue (duplicate symbol),
    797   //      while the second prevent too aggressive optimizations in fast-math mode:
    798   #define EIGEN_TMP_NOOPT_ATTRIB EIGEN_DEVICE_FUNC inline __attribute__((noinline,optimize("no-finite-math-only")))
    799 #endif
    800 
    801 template<> EIGEN_TMP_NOOPT_ATTRIB bool isnan_impl(const long double& x) { return __builtin_isnan(x); }
    802 template<> EIGEN_TMP_NOOPT_ATTRIB bool isnan_impl(const double& x)      { return __builtin_isnan(x); }
    803 template<> EIGEN_TMP_NOOPT_ATTRIB bool isnan_impl(const float& x)       { return __builtin_isnan(x); }
    804 template<> EIGEN_TMP_NOOPT_ATTRIB bool isinf_impl(const double& x)      { return __builtin_isinf(x); }
    805 template<> EIGEN_TMP_NOOPT_ATTRIB bool isinf_impl(const float& x)       { return __builtin_isinf(x); }
    806 template<> EIGEN_TMP_NOOPT_ATTRIB bool isinf_impl(const long double& x) { return __builtin_isinf(x); }
    807 
    808 #undef EIGEN_TMP_NOOPT_ATTRIB
    809 
    810 #endif
    811 
    812 #endif
    813 
    814 // The following overload are defined at the end of this file
    815 template<typename T> EIGEN_DEVICE_FUNC bool isfinite_impl(const std::complex<T>& x);
    816 template<typename T> EIGEN_DEVICE_FUNC bool isnan_impl(const std::complex<T>& x);
    817 template<typename T> EIGEN_DEVICE_FUNC bool isinf_impl(const std::complex<T>& x);
    818 
    819 template<typename T> T generic_fast_tanh_float(const T& a_x);
    820 
    821 } // end namespace internal
    822 
    823 /****************************************************************************
    824 * Generic math functions                                                    *
    825 ****************************************************************************/
    826 
    827 namespace numext {
    828 
    829 #ifndef __CUDA_ARCH__
    830 template<typename T>
    831 EIGEN_DEVICE_FUNC
    832 EIGEN_ALWAYS_INLINE T mini(const T& x, const T& y)
    833 {
    834   EIGEN_USING_STD_MATH(min);
    835   return min EIGEN_NOT_A_MACRO (x,y);
    836 }
    837 
    838 template<typename T>
    839 EIGEN_DEVICE_FUNC
    840 EIGEN_ALWAYS_INLINE T maxi(const T& x, const T& y)
    841 {
    842   EIGEN_USING_STD_MATH(max);
    843   return max EIGEN_NOT_A_MACRO (x,y);
    844 }
    845 #else
    846 template<typename T>
    847 EIGEN_DEVICE_FUNC
    848 EIGEN_ALWAYS_INLINE T mini(const T& x, const T& y)
    849 {
    850   return y < x ? y : x;
    851 }
    852 template<>
    853 EIGEN_DEVICE_FUNC
    854 EIGEN_ALWAYS_INLINE float mini(const float& x, const float& y)
    855 {
    856   return fminf(x, y);
    857 }
    858 template<typename T>
    859 EIGEN_DEVICE_FUNC
    860 EIGEN_ALWAYS_INLINE T maxi(const T& x, const T& y)
    861 {
    862   return x < y ? y : x;
    863 }
    864 template<>
    865 EIGEN_DEVICE_FUNC
    866 EIGEN_ALWAYS_INLINE float maxi(const float& x, const float& y)
    867 {
    868   return fmaxf(x, y);
    869 }
    870 #endif
    871 
    872 
    873 template<typename Scalar>
    874 EIGEN_DEVICE_FUNC
    875 inline EIGEN_MATHFUNC_RETVAL(real, Scalar) real(const Scalar& x)
    876 {
    877   return EIGEN_MATHFUNC_IMPL(real, Scalar)::run(x);
    878 }
    879 
    880 template<typename Scalar>
    881 EIGEN_DEVICE_FUNC
    882 inline typename internal::add_const_on_value_type< EIGEN_MATHFUNC_RETVAL(real_ref, Scalar) >::type real_ref(const Scalar& x)
    883 {
    884   return internal::real_ref_impl<Scalar>::run(x);
    885 }
    886 
    887 template<typename Scalar>
    888 EIGEN_DEVICE_FUNC
    889 inline EIGEN_MATHFUNC_RETVAL(real_ref, Scalar) real_ref(Scalar& x)
    890 {
    891   return EIGEN_MATHFUNC_IMPL(real_ref, Scalar)::run(x);
    892 }
    893 
    894 template<typename Scalar>
    895 EIGEN_DEVICE_FUNC
    896 inline EIGEN_MATHFUNC_RETVAL(imag, Scalar) imag(const Scalar& x)
    897 {
    898   return EIGEN_MATHFUNC_IMPL(imag, Scalar)::run(x);
    899 }
    900 
    901 template<typename Scalar>
    902 EIGEN_DEVICE_FUNC
    903 inline EIGEN_MATHFUNC_RETVAL(arg, Scalar) arg(const Scalar& x)
    904 {
    905   return EIGEN_MATHFUNC_IMPL(arg, Scalar)::run(x);
    906 }
    907 
    908 template<typename Scalar>
    909 EIGEN_DEVICE_FUNC
    910 inline typename internal::add_const_on_value_type< EIGEN_MATHFUNC_RETVAL(imag_ref, Scalar) >::type imag_ref(const Scalar& x)
    911 {
    912   return internal::imag_ref_impl<Scalar>::run(x);
    913 }
    914 
    915 template<typename Scalar>
    916 EIGEN_DEVICE_FUNC
    917 inline EIGEN_MATHFUNC_RETVAL(imag_ref, Scalar) imag_ref(Scalar& x)
    918 {
    919   return EIGEN_MATHFUNC_IMPL(imag_ref, Scalar)::run(x);
    920 }
    921 
    922 template<typename Scalar>
    923 EIGEN_DEVICE_FUNC
    924 inline EIGEN_MATHFUNC_RETVAL(conj, Scalar) conj(const Scalar& x)
    925 {
    926   return EIGEN_MATHFUNC_IMPL(conj, Scalar)::run(x);
    927 }
    928 
    929 template<typename Scalar>
    930 EIGEN_DEVICE_FUNC
    931 inline EIGEN_MATHFUNC_RETVAL(abs2, Scalar) abs2(const Scalar& x)
    932 {
    933   return EIGEN_MATHFUNC_IMPL(abs2, Scalar)::run(x);
    934 }
    935 
    936 template<typename Scalar>
    937 EIGEN_DEVICE_FUNC
    938 inline EIGEN_MATHFUNC_RETVAL(norm1, Scalar) norm1(const Scalar& x)
    939 {
    940   return EIGEN_MATHFUNC_IMPL(norm1, Scalar)::run(x);
    941 }
    942 
    943 template<typename Scalar>
    944 EIGEN_DEVICE_FUNC
    945 inline EIGEN_MATHFUNC_RETVAL(hypot, Scalar) hypot(const Scalar& x, const Scalar& y)
    946 {
    947   return EIGEN_MATHFUNC_IMPL(hypot, Scalar)::run(x, y);
    948 }
    949 
    950 template<typename Scalar>
    951 EIGEN_DEVICE_FUNC
    952 inline EIGEN_MATHFUNC_RETVAL(log1p, Scalar) log1p(const Scalar& x)
    953 {
    954   return EIGEN_MATHFUNC_IMPL(log1p, Scalar)::run(x);
    955 }
    956 
    957 #ifdef __CUDACC__
    958 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
    959 float log1p(const float &x) { return ::log1pf(x); }
    960 
    961 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
    962 double log1p(const double &x) { return ::log1p(x); }
    963 #endif
    964 
    965 template<typename ScalarX,typename ScalarY>
    966 EIGEN_DEVICE_FUNC
    967 inline typename internal::pow_impl<ScalarX,ScalarY>::result_type pow(const ScalarX& x, const ScalarY& y)
    968 {
    969   return internal::pow_impl<ScalarX,ScalarY>::run(x, y);
    970 }
    971 
    972 template<typename T> EIGEN_DEVICE_FUNC bool (isnan)   (const T &x) { return internal::isnan_impl(x); }
    973 template<typename T> EIGEN_DEVICE_FUNC bool (isinf)   (const T &x) { return internal::isinf_impl(x); }
    974 template<typename T> EIGEN_DEVICE_FUNC bool (isfinite)(const T &x) { return internal::isfinite_impl(x); }
    975 
    976 template<typename Scalar>
    977 EIGEN_DEVICE_FUNC
    978 inline EIGEN_MATHFUNC_RETVAL(round, Scalar) round(const Scalar& x)
    979 {
    980   return EIGEN_MATHFUNC_IMPL(round, Scalar)::run(x);
    981 }
    982 
    983 template<typename T>
    984 EIGEN_DEVICE_FUNC
    985 T (floor)(const T& x)
    986 {
    987   EIGEN_USING_STD_MATH(floor);
    988   return floor(x);
    989 }
    990 
    991 #ifdef __CUDACC__
    992 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
    993 float floor(const float &x) { return ::floorf(x); }
    994 
    995 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
    996 double floor(const double &x) { return ::floor(x); }
    997 #endif
    998 
    999 template<typename T>
   1000 EIGEN_DEVICE_FUNC
   1001 T (ceil)(const T& x)
   1002 {
   1003   EIGEN_USING_STD_MATH(ceil);
   1004   return ceil(x);
   1005 }
   1006 
   1007 #ifdef __CUDACC__
   1008 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1009 float ceil(const float &x) { return ::ceilf(x); }
   1010 
   1011 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1012 double ceil(const double &x) { return ::ceil(x); }
   1013 #endif
   1014 
   1015 
   1016 /** Log base 2 for 32 bits positive integers.
   1017   * Conveniently returns 0 for x==0. */
   1018 inline int log2(int x)
   1019 {
   1020   eigen_assert(x>=0);
   1021   unsigned int v(x);
   1022   static const int table[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };
   1023   v |= v >> 1;
   1024   v |= v >> 2;
   1025   v |= v >> 4;
   1026   v |= v >> 8;
   1027   v |= v >> 16;
   1028   return table[(v * 0x07C4ACDDU) >> 27];
   1029 }
   1030 
   1031 /** \returns the square root of \a x.
   1032   *
   1033   * It is essentially equivalent to \code using std::sqrt; return sqrt(x); \endcode,
   1034   * but slightly faster for float/double and some compilers (e.g., gcc), thanks to
   1035   * specializations when SSE is enabled.
   1036   *
   1037   * It's usage is justified in performance critical functions, like norm/normalize.
   1038   */
   1039 template<typename T>
   1040 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1041 T sqrt(const T &x)
   1042 {
   1043   EIGEN_USING_STD_MATH(sqrt);
   1044   return sqrt(x);
   1045 }
   1046 
   1047 template<typename T>
   1048 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1049 T log(const T &x) {
   1050   EIGEN_USING_STD_MATH(log);
   1051   return log(x);
   1052 }
   1053 
   1054 #ifdef __CUDACC__
   1055 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1056 float log(const float &x) { return ::logf(x); }
   1057 
   1058 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1059 double log(const double &x) { return ::log(x); }
   1060 #endif
   1061 
   1062 template<typename T>
   1063 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1064 typename internal::enable_if<NumTraits<T>::IsSigned || NumTraits<T>::IsComplex,typename NumTraits<T>::Real>::type
   1065 abs(const T &x) {
   1066   EIGEN_USING_STD_MATH(abs);
   1067   return abs(x);
   1068 }
   1069 
   1070 template<typename T>
   1071 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1072 typename internal::enable_if<!(NumTraits<T>::IsSigned || NumTraits<T>::IsComplex),typename NumTraits<T>::Real>::type
   1073 abs(const T &x) {
   1074   return x;
   1075 }
   1076 
   1077 #if defined(__SYCL_DEVICE_ONLY__)
   1078 EIGEN_ALWAYS_INLINE float   abs(float x) { return cl::sycl::fabs(x); }
   1079 EIGEN_ALWAYS_INLINE double  abs(double x) { return cl::sycl::fabs(x); }
   1080 #endif // defined(__SYCL_DEVICE_ONLY__)
   1081 
   1082 #ifdef __CUDACC__
   1083 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1084 float abs(const float &x) { return ::fabsf(x); }
   1085 
   1086 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1087 double abs(const double &x) { return ::fabs(x); }
   1088 
   1089 template <> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1090 float abs(const std::complex<float>& x) {
   1091   return ::hypotf(x.real(), x.imag());
   1092 }
   1093 
   1094 template <> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1095 double abs(const std::complex<double>& x) {
   1096   return ::hypot(x.real(), x.imag());
   1097 }
   1098 #endif
   1099 
   1100 template<typename T>
   1101 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1102 T exp(const T &x) {
   1103   EIGEN_USING_STD_MATH(exp);
   1104   return exp(x);
   1105 }
   1106 
   1107 #ifdef __CUDACC__
   1108 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1109 float exp(const float &x) { return ::expf(x); }
   1110 
   1111 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1112 double exp(const double &x) { return ::exp(x); }
   1113 #endif
   1114 
   1115 template<typename T>
   1116 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1117 T cos(const T &x) {
   1118   EIGEN_USING_STD_MATH(cos);
   1119   return cos(x);
   1120 }
   1121 
   1122 #ifdef __CUDACC__
   1123 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1124 float cos(const float &x) { return ::cosf(x); }
   1125 
   1126 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1127 double cos(const double &x) { return ::cos(x); }
   1128 #endif
   1129 
   1130 template<typename T>
   1131 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1132 T sin(const T &x) {
   1133   EIGEN_USING_STD_MATH(sin);
   1134   return sin(x);
   1135 }
   1136 
   1137 #ifdef __CUDACC__
   1138 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1139 float sin(const float &x) { return ::sinf(x); }
   1140 
   1141 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1142 double sin(const double &x) { return ::sin(x); }
   1143 #endif
   1144 
   1145 template<typename T>
   1146 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1147 T tan(const T &x) {
   1148   EIGEN_USING_STD_MATH(tan);
   1149   return tan(x);
   1150 }
   1151 
   1152 #ifdef __CUDACC__
   1153 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1154 float tan(const float &x) { return ::tanf(x); }
   1155 
   1156 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1157 double tan(const double &x) { return ::tan(x); }
   1158 #endif
   1159 
   1160 template<typename T>
   1161 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1162 T acos(const T &x) {
   1163   EIGEN_USING_STD_MATH(acos);
   1164   return acos(x);
   1165 }
   1166 
   1167 #ifdef __CUDACC__
   1168 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1169 float acos(const float &x) { return ::acosf(x); }
   1170 
   1171 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1172 double acos(const double &x) { return ::acos(x); }
   1173 #endif
   1174 
   1175 template<typename T>
   1176 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1177 T asin(const T &x) {
   1178   EIGEN_USING_STD_MATH(asin);
   1179   return asin(x);
   1180 }
   1181 
   1182 #ifdef __CUDACC__
   1183 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1184 float asin(const float &x) { return ::asinf(x); }
   1185 
   1186 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1187 double asin(const double &x) { return ::asin(x); }
   1188 #endif
   1189 
   1190 template<typename T>
   1191 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1192 T atan(const T &x) {
   1193   EIGEN_USING_STD_MATH(atan);
   1194   return atan(x);
   1195 }
   1196 
   1197 #ifdef __CUDACC__
   1198 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1199 float atan(const float &x) { return ::atanf(x); }
   1200 
   1201 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1202 double atan(const double &x) { return ::atan(x); }
   1203 #endif
   1204 
   1205 
   1206 template<typename T>
   1207 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1208 T cosh(const T &x) {
   1209   EIGEN_USING_STD_MATH(cosh);
   1210   return cosh(x);
   1211 }
   1212 
   1213 #ifdef __CUDACC__
   1214 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1215 float cosh(const float &x) { return ::coshf(x); }
   1216 
   1217 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1218 double cosh(const double &x) { return ::cosh(x); }
   1219 #endif
   1220 
   1221 template<typename T>
   1222 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1223 T sinh(const T &x) {
   1224   EIGEN_USING_STD_MATH(sinh);
   1225   return sinh(x);
   1226 }
   1227 
   1228 #ifdef __CUDACC__
   1229 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1230 float sinh(const float &x) { return ::sinhf(x); }
   1231 
   1232 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1233 double sinh(const double &x) { return ::sinh(x); }
   1234 #endif
   1235 
   1236 template<typename T>
   1237 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1238 T tanh(const T &x) {
   1239   EIGEN_USING_STD_MATH(tanh);
   1240   return tanh(x);
   1241 }
   1242 
   1243 #if (!defined(__CUDACC__)) && EIGEN_FAST_MATH
   1244 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1245 float tanh(float x) { return internal::generic_fast_tanh_float(x); }
   1246 #endif
   1247 
   1248 #ifdef __CUDACC__
   1249 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1250 float tanh(const float &x) { return ::tanhf(x); }
   1251 
   1252 template<> EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1253 double tanh(const double &x) { return ::tanh(x); }
   1254 #endif
   1255 
   1256 template <typename T>
   1257 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1258 T fmod(const T& a, const T& b) {
   1259   EIGEN_USING_STD_MATH(fmod);
   1260   return fmod(a, b);
   1261 }
   1262 
   1263 #ifdef __CUDACC__
   1264 template <>
   1265 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1266 float fmod(const float& a, const float& b) {
   1267   return ::fmodf(a, b);
   1268 }
   1269 
   1270 template <>
   1271 EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
   1272 double fmod(const double& a, const double& b) {
   1273   return ::fmod(a, b);
   1274 }
   1275 #endif
   1276 
   1277 } // end namespace numext
   1278 
   1279 namespace internal {
   1280 
   1281 template<typename T>
   1282 EIGEN_DEVICE_FUNC bool isfinite_impl(const std::complex<T>& x)
   1283 {
   1284   return (numext::isfinite)(numext::real(x)) && (numext::isfinite)(numext::imag(x));
   1285 }
   1286 
   1287 template<typename T>
   1288 EIGEN_DEVICE_FUNC bool isnan_impl(const std::complex<T>& x)
   1289 {
   1290   return (numext::isnan)(numext::real(x)) || (numext::isnan)(numext::imag(x));
   1291 }
   1292 
   1293 template<typename T>
   1294 EIGEN_DEVICE_FUNC bool isinf_impl(const std::complex<T>& x)
   1295 {
   1296   return ((numext::isinf)(numext::real(x)) || (numext::isinf)(numext::imag(x))) && (!(numext::isnan)(x));
   1297 }
   1298 
   1299 /****************************************************************************
   1300 * Implementation of fuzzy comparisons                                       *
   1301 ****************************************************************************/
   1302 
   1303 template<typename Scalar,
   1304          bool IsComplex,
   1305          bool IsInteger>
   1306 struct scalar_fuzzy_default_impl {};
   1307 
   1308 template<typename Scalar>
   1309 struct scalar_fuzzy_default_impl<Scalar, false, false>
   1310 {
   1311   typedef typename NumTraits<Scalar>::Real RealScalar;
   1312   template<typename OtherScalar> EIGEN_DEVICE_FUNC
   1313   static inline bool isMuchSmallerThan(const Scalar& x, const OtherScalar& y, const RealScalar& prec)
   1314   {
   1315     return numext::abs(x) <= numext::abs(y) * prec;
   1316   }
   1317   EIGEN_DEVICE_FUNC
   1318   static inline bool isApprox(const Scalar& x, const Scalar& y, const RealScalar& prec)
   1319   {
   1320     return numext::abs(x - y) <= numext::mini(numext::abs(x), numext::abs(y)) * prec;
   1321   }
   1322   EIGEN_DEVICE_FUNC
   1323   static inline bool isApproxOrLessThan(const Scalar& x, const Scalar& y, const RealScalar& prec)
   1324   {
   1325     return x <= y || isApprox(x, y, prec);
   1326   }
   1327 };
   1328 
   1329 template<typename Scalar>
   1330 struct scalar_fuzzy_default_impl<Scalar, false, true>
   1331 {
   1332   typedef typename NumTraits<Scalar>::Real RealScalar;
   1333   template<typename OtherScalar> EIGEN_DEVICE_FUNC
   1334   static inline bool isMuchSmallerThan(const Scalar& x, const Scalar&, const RealScalar&)
   1335   {
   1336     return x == Scalar(0);
   1337   }
   1338   EIGEN_DEVICE_FUNC
   1339   static inline bool isApprox(const Scalar& x, const Scalar& y, const RealScalar&)
   1340   {
   1341     return x == y;
   1342   }
   1343   EIGEN_DEVICE_FUNC
   1344   static inline bool isApproxOrLessThan(const Scalar& x, const Scalar& y, const RealScalar&)
   1345   {
   1346     return x <= y;
   1347   }
   1348 };
   1349 
   1350 template<typename Scalar>
   1351 struct scalar_fuzzy_default_impl<Scalar, true, false>
   1352 {
   1353   typedef typename NumTraits<Scalar>::Real RealScalar;
   1354   template<typename OtherScalar> EIGEN_DEVICE_FUNC
   1355   static inline bool isMuchSmallerThan(const Scalar& x, const OtherScalar& y, const RealScalar& prec)
   1356   {
   1357     return numext::abs2(x) <= numext::abs2(y) * prec * prec;
   1358   }
   1359   EIGEN_DEVICE_FUNC
   1360   static inline bool isApprox(const Scalar& x, const Scalar& y, const RealScalar& prec)
   1361   {
   1362     return numext::abs2(x - y) <= numext::mini(numext::abs2(x), numext::abs2(y)) * prec * prec;
   1363   }
   1364 };
   1365 
   1366 template<typename Scalar>
   1367 struct scalar_fuzzy_impl : scalar_fuzzy_default_impl<Scalar, NumTraits<Scalar>::IsComplex, NumTraits<Scalar>::IsInteger> {};
   1368 
   1369 template<typename Scalar, typename OtherScalar> EIGEN_DEVICE_FUNC
   1370 inline bool isMuchSmallerThan(const Scalar& x, const OtherScalar& y,
   1371                               const typename NumTraits<Scalar>::Real &precision = NumTraits<Scalar>::dummy_precision())
   1372 {
   1373   return scalar_fuzzy_impl<Scalar>::template isMuchSmallerThan<OtherScalar>(x, y, precision);
   1374 }
   1375 
   1376 template<typename Scalar> EIGEN_DEVICE_FUNC
   1377 inline bool isApprox(const Scalar& x, const Scalar& y,
   1378                      const typename NumTraits<Scalar>::Real &precision = NumTraits<Scalar>::dummy_precision())
   1379 {
   1380   return scalar_fuzzy_impl<Scalar>::isApprox(x, y, precision);
   1381 }
   1382 
   1383 template<typename Scalar> EIGEN_DEVICE_FUNC
   1384 inline bool isApproxOrLessThan(const Scalar& x, const Scalar& y,
   1385                                const typename NumTraits<Scalar>::Real &precision = NumTraits<Scalar>::dummy_precision())
   1386 {
   1387   return scalar_fuzzy_impl<Scalar>::isApproxOrLessThan(x, y, precision);
   1388 }
   1389 
   1390 /******************************************
   1391 ***  The special case of the  bool type ***
   1392 ******************************************/
   1393 
   1394 template<> struct random_impl<bool>
   1395 {
   1396   static inline bool run()
   1397   {
   1398     return random<int>(0,1)==0 ? false : true;
   1399   }
   1400 };
   1401 
   1402 template<> struct scalar_fuzzy_impl<bool>
   1403 {
   1404   typedef bool RealScalar;
   1405 
   1406   template<typename OtherScalar> EIGEN_DEVICE_FUNC
   1407   static inline bool isMuchSmallerThan(const bool& x, const bool&, const bool&)
   1408   {
   1409     return !x;
   1410   }
   1411 
   1412   EIGEN_DEVICE_FUNC
   1413   static inline bool isApprox(bool x, bool y, bool)
   1414   {
   1415     return x == y;
   1416   }
   1417 
   1418   EIGEN_DEVICE_FUNC
   1419   static inline bool isApproxOrLessThan(const bool& x, const bool& y, const bool&)
   1420   {
   1421     return (!x) || y;
   1422   }
   1423 
   1424 };
   1425 
   1426 
   1427 } // end namespace internal
   1428 
   1429 } // end namespace Eigen
   1430 
   1431 #endif // EIGEN_MATHFUNCTIONS_H
   1432