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1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2008-2010 Gael Guennebaud <gael.guennebaud@inria.fr>
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_FUNCTORS_H
11 #define EIGEN_FUNCTORS_H
12 
13 namespace Eigen {
14 
15 namespace internal {
16 
17 // associative functors:
18 
19 /** \internal
20   * \brief Template functor to compute the sum of two scalars
21   *
22   * \sa class CwiseBinaryOp, MatrixBase::operator+, class VectorwiseOp, MatrixBase::sum()
23   */
24 template<typename Scalar> struct scalar_sum_op {
EIGEN_EMPTY_STRUCT_CTORscalar_sum_op25   EIGEN_EMPTY_STRUCT_CTOR(scalar_sum_op)
26   EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a, const Scalar& b) const { return a + b; }
27   template<typename Packet>
packetOpscalar_sum_op28   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const
29   { return internal::padd(a,b); }
30   template<typename Packet>
preduxscalar_sum_op31   EIGEN_STRONG_INLINE const Scalar predux(const Packet& a) const
32   { return internal::predux(a); }
33 };
34 template<typename Scalar>
35 struct functor_traits<scalar_sum_op<Scalar> > {
36   enum {
37     Cost = NumTraits<Scalar>::AddCost,
38     PacketAccess = packet_traits<Scalar>::HasAdd
39   };
40 };
41 
42 /** \internal
43   * \brief Template functor to compute the product of two scalars
44   *
45   * \sa class CwiseBinaryOp, Cwise::operator*(), class VectorwiseOp, MatrixBase::redux()
46   */
47 template<typename LhsScalar,typename RhsScalar> struct scalar_product_op {
48   enum {
49     // TODO vectorize mixed product
50     Vectorizable = is_same<LhsScalar,RhsScalar>::value && packet_traits<LhsScalar>::HasMul && packet_traits<RhsScalar>::HasMul
51   };
52   typedef typename scalar_product_traits<LhsScalar,RhsScalar>::ReturnType result_type;
53   EIGEN_EMPTY_STRUCT_CTOR(scalar_product_op)
54   EIGEN_STRONG_INLINE const result_type operator() (const LhsScalar& a, const RhsScalar& b) const { return a * b; }
55   template<typename Packet>
56   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const
57   { return internal::pmul(a,b); }
58   template<typename Packet>
59   EIGEN_STRONG_INLINE const result_type predux(const Packet& a) const
60   { return internal::predux_mul(a); }
61 };
62 template<typename LhsScalar,typename RhsScalar>
63 struct functor_traits<scalar_product_op<LhsScalar,RhsScalar> > {
64   enum {
65     Cost = (NumTraits<LhsScalar>::MulCost + NumTraits<RhsScalar>::MulCost)/2, // rough estimate!
66     PacketAccess = scalar_product_op<LhsScalar,RhsScalar>::Vectorizable
67   };
68 };
69 
70 /** \internal
71   * \brief Template functor to compute the conjugate product of two scalars
72   *
73   * This is a short cut for conj(x) * y which is needed for optimization purpose; in Eigen2 support mode, this becomes x * conj(y)
74   */
75 template<typename LhsScalar,typename RhsScalar> struct scalar_conj_product_op {
76 
77   enum {
78     Conj = NumTraits<LhsScalar>::IsComplex
79   };
80 
81   typedef typename scalar_product_traits<LhsScalar,RhsScalar>::ReturnType result_type;
82 
83   EIGEN_EMPTY_STRUCT_CTOR(scalar_conj_product_op)
84   EIGEN_STRONG_INLINE const result_type operator() (const LhsScalar& a, const RhsScalar& b) const
85   { return conj_helper<LhsScalar,RhsScalar,Conj,false>().pmul(a,b); }
86 
87   template<typename Packet>
88   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const
89   { return conj_helper<Packet,Packet,Conj,false>().pmul(a,b); }
90 };
91 template<typename LhsScalar,typename RhsScalar>
92 struct functor_traits<scalar_conj_product_op<LhsScalar,RhsScalar> > {
93   enum {
94     Cost = NumTraits<LhsScalar>::MulCost,
95     PacketAccess = internal::is_same<LhsScalar, RhsScalar>::value && packet_traits<LhsScalar>::HasMul
96   };
97 };
98 
99 /** \internal
100   * \brief Template functor to compute the min of two scalars
101   *
102   * \sa class CwiseBinaryOp, MatrixBase::cwiseMin, class VectorwiseOp, MatrixBase::minCoeff()
103   */
104 template<typename Scalar> struct scalar_min_op {
105   EIGEN_EMPTY_STRUCT_CTOR(scalar_min_op)
106   EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a, const Scalar& b) const { using std::min; return (min)(a, b); }
107   template<typename Packet>
108   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const
109   { return internal::pmin(a,b); }
110   template<typename Packet>
111   EIGEN_STRONG_INLINE const Scalar predux(const Packet& a) const
112   { return internal::predux_min(a); }
113 };
114 template<typename Scalar>
115 struct functor_traits<scalar_min_op<Scalar> > {
116   enum {
117     Cost = NumTraits<Scalar>::AddCost,
118     PacketAccess = packet_traits<Scalar>::HasMin
119   };
120 };
121 
122 /** \internal
123   * \brief Template functor to compute the max of two scalars
124   *
125   * \sa class CwiseBinaryOp, MatrixBase::cwiseMax, class VectorwiseOp, MatrixBase::maxCoeff()
126   */
127 template<typename Scalar> struct scalar_max_op {
128   EIGEN_EMPTY_STRUCT_CTOR(scalar_max_op)
129   EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a, const Scalar& b) const { using std::max; return (max)(a, b); }
130   template<typename Packet>
131   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const
132   { return internal::pmax(a,b); }
133   template<typename Packet>
134   EIGEN_STRONG_INLINE const Scalar predux(const Packet& a) const
135   { return internal::predux_max(a); }
136 };
137 template<typename Scalar>
138 struct functor_traits<scalar_max_op<Scalar> > {
139   enum {
140     Cost = NumTraits<Scalar>::AddCost,
141     PacketAccess = packet_traits<Scalar>::HasMax
142   };
143 };
144 
145 /** \internal
146   * \brief Template functor to compute the hypot of two scalars
147   *
148   * \sa MatrixBase::stableNorm(), class Redux
149   */
150 template<typename Scalar> struct scalar_hypot_op {
151   EIGEN_EMPTY_STRUCT_CTOR(scalar_hypot_op)
152 //   typedef typename NumTraits<Scalar>::Real result_type;
153   EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& _x, const Scalar& _y) const
154   {
155     using std::max;
156     using std::min;
157     Scalar p = (max)(_x, _y);
158     Scalar q = (min)(_x, _y);
159     Scalar qp = q/p;
160     return p * sqrt(Scalar(1) + qp*qp);
161   }
162 };
163 template<typename Scalar>
164 struct functor_traits<scalar_hypot_op<Scalar> > {
165   enum { Cost = 5 * NumTraits<Scalar>::MulCost, PacketAccess=0 };
166 };
167 
168 /** \internal
169   * \brief Template functor to compute the pow of two scalars
170   */
171 template<typename Scalar, typename OtherScalar> struct scalar_binary_pow_op {
172   EIGEN_EMPTY_STRUCT_CTOR(scalar_binary_pow_op)
173   inline Scalar operator() (const Scalar& a, const OtherScalar& b) const { return internal::pow(a, b); }
174 };
175 template<typename Scalar, typename OtherScalar>
176 struct functor_traits<scalar_binary_pow_op<Scalar,OtherScalar> > {
177   enum { Cost = 5 * NumTraits<Scalar>::MulCost, PacketAccess = false };
178 };
179 
180 // other binary functors:
181 
182 /** \internal
183   * \brief Template functor to compute the difference of two scalars
184   *
185   * \sa class CwiseBinaryOp, MatrixBase::operator-
186   */
187 template<typename Scalar> struct scalar_difference_op {
188   EIGEN_EMPTY_STRUCT_CTOR(scalar_difference_op)
189   EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a, const Scalar& b) const { return a - b; }
190   template<typename Packet>
191   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const
192   { return internal::psub(a,b); }
193 };
194 template<typename Scalar>
195 struct functor_traits<scalar_difference_op<Scalar> > {
196   enum {
197     Cost = NumTraits<Scalar>::AddCost,
198     PacketAccess = packet_traits<Scalar>::HasSub
199   };
200 };
201 
202 /** \internal
203   * \brief Template functor to compute the quotient of two scalars
204   *
205   * \sa class CwiseBinaryOp, Cwise::operator/()
206   */
207 template<typename Scalar> struct scalar_quotient_op {
208   EIGEN_EMPTY_STRUCT_CTOR(scalar_quotient_op)
209   EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a, const Scalar& b) const { return a / b; }
210   template<typename Packet>
211   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const
212   { return internal::pdiv(a,b); }
213 };
214 template<typename Scalar>
215 struct functor_traits<scalar_quotient_op<Scalar> > {
216   enum {
217     Cost = 2 * NumTraits<Scalar>::MulCost,
218     PacketAccess = packet_traits<Scalar>::HasDiv
219   };
220 };
221 
222 /** \internal
223   * \brief Template functor to compute the and of two booleans
224   *
225   * \sa class CwiseBinaryOp, ArrayBase::operator&&
226   */
227 struct scalar_boolean_and_op {
228   EIGEN_EMPTY_STRUCT_CTOR(scalar_boolean_and_op)
229   EIGEN_STRONG_INLINE bool operator() (const bool& a, const bool& b) const { return a && b; }
230 };
231 template<> struct functor_traits<scalar_boolean_and_op> {
232   enum {
233     Cost = NumTraits<bool>::AddCost,
234     PacketAccess = false
235   };
236 };
237 
238 /** \internal
239   * \brief Template functor to compute the or of two booleans
240   *
241   * \sa class CwiseBinaryOp, ArrayBase::operator||
242   */
243 struct scalar_boolean_or_op {
244   EIGEN_EMPTY_STRUCT_CTOR(scalar_boolean_or_op)
245   EIGEN_STRONG_INLINE bool operator() (const bool& a, const bool& b) const { return a || b; }
246 };
247 template<> struct functor_traits<scalar_boolean_or_op> {
248   enum {
249     Cost = NumTraits<bool>::AddCost,
250     PacketAccess = false
251   };
252 };
253 
254 // unary functors:
255 
256 /** \internal
257   * \brief Template functor to compute the opposite of a scalar
258   *
259   * \sa class CwiseUnaryOp, MatrixBase::operator-
260   */
261 template<typename Scalar> struct scalar_opposite_op {
262   EIGEN_EMPTY_STRUCT_CTOR(scalar_opposite_op)
263   EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const { return -a; }
264   template<typename Packet>
265   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const
266   { return internal::pnegate(a); }
267 };
268 template<typename Scalar>
269 struct functor_traits<scalar_opposite_op<Scalar> >
270 { enum {
271     Cost = NumTraits<Scalar>::AddCost,
272     PacketAccess = packet_traits<Scalar>::HasNegate };
273 };
274 
275 /** \internal
276   * \brief Template functor to compute the absolute value of a scalar
277   *
278   * \sa class CwiseUnaryOp, Cwise::abs
279   */
280 template<typename Scalar> struct scalar_abs_op {
281   EIGEN_EMPTY_STRUCT_CTOR(scalar_abs_op)
282   typedef typename NumTraits<Scalar>::Real result_type;
283   EIGEN_STRONG_INLINE const result_type operator() (const Scalar& a) const { return internal::abs(a); }
284   template<typename Packet>
285   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const
286   { return internal::pabs(a); }
287 };
288 template<typename Scalar>
289 struct functor_traits<scalar_abs_op<Scalar> >
290 {
291   enum {
292     Cost = NumTraits<Scalar>::AddCost,
293     PacketAccess = packet_traits<Scalar>::HasAbs
294   };
295 };
296 
297 /** \internal
298   * \brief Template functor to compute the squared absolute value of a scalar
299   *
300   * \sa class CwiseUnaryOp, Cwise::abs2
301   */
302 template<typename Scalar> struct scalar_abs2_op {
303   EIGEN_EMPTY_STRUCT_CTOR(scalar_abs2_op)
304   typedef typename NumTraits<Scalar>::Real result_type;
305   EIGEN_STRONG_INLINE const result_type operator() (const Scalar& a) const { return internal::abs2(a); }
306   template<typename Packet>
307   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const
308   { return internal::pmul(a,a); }
309 };
310 template<typename Scalar>
311 struct functor_traits<scalar_abs2_op<Scalar> >
312 { enum { Cost = NumTraits<Scalar>::MulCost, PacketAccess = packet_traits<Scalar>::HasAbs2 }; };
313 
314 /** \internal
315   * \brief Template functor to compute the conjugate of a complex value
316   *
317   * \sa class CwiseUnaryOp, MatrixBase::conjugate()
318   */
319 template<typename Scalar> struct scalar_conjugate_op {
320   EIGEN_EMPTY_STRUCT_CTOR(scalar_conjugate_op)
321   EIGEN_STRONG_INLINE const Scalar operator() (const Scalar& a) const { return internal::conj(a); }
322   template<typename Packet>
323   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const { return internal::pconj(a); }
324 };
325 template<typename Scalar>
326 struct functor_traits<scalar_conjugate_op<Scalar> >
327 {
328   enum {
329     Cost = NumTraits<Scalar>::IsComplex ? NumTraits<Scalar>::AddCost : 0,
330     PacketAccess = packet_traits<Scalar>::HasConj
331   };
332 };
333 
334 /** \internal
335   * \brief Template functor to cast a scalar to another type
336   *
337   * \sa class CwiseUnaryOp, MatrixBase::cast()
338   */
339 template<typename Scalar, typename NewType>
340 struct scalar_cast_op {
341   EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
342   typedef NewType result_type;
343   EIGEN_STRONG_INLINE const NewType operator() (const Scalar& a) const { return cast<Scalar, NewType>(a); }
344 };
345 template<typename Scalar, typename NewType>
346 struct functor_traits<scalar_cast_op<Scalar,NewType> >
347 { enum { Cost = is_same<Scalar, NewType>::value ? 0 : NumTraits<NewType>::AddCost, PacketAccess = false }; };
348 
349 /** \internal
350   * \brief Template functor to extract the real part of a complex
351   *
352   * \sa class CwiseUnaryOp, MatrixBase::real()
353   */
354 template<typename Scalar>
355 struct scalar_real_op {
356   EIGEN_EMPTY_STRUCT_CTOR(scalar_real_op)
357   typedef typename NumTraits<Scalar>::Real result_type;
358   EIGEN_STRONG_INLINE result_type operator() (const Scalar& a) const { return internal::real(a); }
359 };
360 template<typename Scalar>
361 struct functor_traits<scalar_real_op<Scalar> >
362 { enum { Cost = 0, PacketAccess = false }; };
363 
364 /** \internal
365   * \brief Template functor to extract the imaginary part of a complex
366   *
367   * \sa class CwiseUnaryOp, MatrixBase::imag()
368   */
369 template<typename Scalar>
370 struct scalar_imag_op {
371   EIGEN_EMPTY_STRUCT_CTOR(scalar_imag_op)
372   typedef typename NumTraits<Scalar>::Real result_type;
373   EIGEN_STRONG_INLINE result_type operator() (const Scalar& a) const { return internal::imag(a); }
374 };
375 template<typename Scalar>
376 struct functor_traits<scalar_imag_op<Scalar> >
377 { enum { Cost = 0, PacketAccess = false }; };
378 
379 /** \internal
380   * \brief Template functor to extract the real part of a complex as a reference
381   *
382   * \sa class CwiseUnaryOp, MatrixBase::real()
383   */
384 template<typename Scalar>
385 struct scalar_real_ref_op {
386   EIGEN_EMPTY_STRUCT_CTOR(scalar_real_ref_op)
387   typedef typename NumTraits<Scalar>::Real result_type;
388   EIGEN_STRONG_INLINE result_type& operator() (const Scalar& a) const { return internal::real_ref(*const_cast<Scalar*>(&a)); }
389 };
390 template<typename Scalar>
391 struct functor_traits<scalar_real_ref_op<Scalar> >
392 { enum { Cost = 0, PacketAccess = false }; };
393 
394 /** \internal
395   * \brief Template functor to extract the imaginary part of a complex as a reference
396   *
397   * \sa class CwiseUnaryOp, MatrixBase::imag()
398   */
399 template<typename Scalar>
400 struct scalar_imag_ref_op {
401   EIGEN_EMPTY_STRUCT_CTOR(scalar_imag_ref_op)
402   typedef typename NumTraits<Scalar>::Real result_type;
403   EIGEN_STRONG_INLINE result_type& operator() (const Scalar& a) const { return internal::imag_ref(*const_cast<Scalar*>(&a)); }
404 };
405 template<typename Scalar>
406 struct functor_traits<scalar_imag_ref_op<Scalar> >
407 { enum { Cost = 0, PacketAccess = false }; };
408 
409 /** \internal
410   *
411   * \brief Template functor to compute the exponential of a scalar
412   *
413   * \sa class CwiseUnaryOp, Cwise::exp()
414   */
415 template<typename Scalar> struct scalar_exp_op {
416   EIGEN_EMPTY_STRUCT_CTOR(scalar_exp_op)
417   inline const Scalar operator() (const Scalar& a) const { return internal::exp(a); }
418   typedef typename packet_traits<Scalar>::type Packet;
419   inline Packet packetOp(const Packet& a) const { return internal::pexp(a); }
420 };
421 template<typename Scalar>
422 struct functor_traits<scalar_exp_op<Scalar> >
423 { enum { Cost = 5 * NumTraits<Scalar>::MulCost, PacketAccess = packet_traits<Scalar>::HasExp }; };
424 
425 /** \internal
426   *
427   * \brief Template functor to compute the logarithm of a scalar
428   *
429   * \sa class CwiseUnaryOp, Cwise::log()
430   */
431 template<typename Scalar> struct scalar_log_op {
432   EIGEN_EMPTY_STRUCT_CTOR(scalar_log_op)
433   inline const Scalar operator() (const Scalar& a) const { return internal::log(a); }
434   typedef typename packet_traits<Scalar>::type Packet;
435   inline Packet packetOp(const Packet& a) const { return internal::plog(a); }
436 };
437 template<typename Scalar>
438 struct functor_traits<scalar_log_op<Scalar> >
439 { enum { Cost = 5 * NumTraits<Scalar>::MulCost, PacketAccess = packet_traits<Scalar>::HasLog }; };
440 
441 /** \internal
442   * \brief Template functor to multiply a scalar by a fixed other one
443   *
444   * \sa class CwiseUnaryOp, MatrixBase::operator*, MatrixBase::operator/
445   */
446 /* NOTE why doing the pset1() in packetOp *is* an optimization ?
447  * indeed it seems better to declare m_other as a Packet and do the pset1() once
448  * in the constructor. However, in practice:
449  *  - GCC does not like m_other as a Packet and generate a load every time it needs it
450  *  - on the other hand GCC is able to moves the pset1() away the loop :)
451  *  - simpler code ;)
452  * (ICC and gcc 4.4 seems to perform well in both cases, the issue is visible with y = a*x + b*y)
453  */
454 template<typename Scalar>
455 struct scalar_multiple_op {
456   typedef typename packet_traits<Scalar>::type Packet;
457   // FIXME default copy constructors seems bugged with std::complex<>
458   EIGEN_STRONG_INLINE scalar_multiple_op(const scalar_multiple_op& other) : m_other(other.m_other) { }
459   EIGEN_STRONG_INLINE scalar_multiple_op(const Scalar& other) : m_other(other) { }
460   EIGEN_STRONG_INLINE Scalar operator() (const Scalar& a) const { return a * m_other; }
461   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const
462   { return internal::pmul(a, pset1<Packet>(m_other)); }
463   typename add_const_on_value_type<typename NumTraits<Scalar>::Nested>::type m_other;
464 };
465 template<typename Scalar>
466 struct functor_traits<scalar_multiple_op<Scalar> >
467 { enum { Cost = NumTraits<Scalar>::MulCost, PacketAccess = packet_traits<Scalar>::HasMul }; };
468 
469 template<typename Scalar1, typename Scalar2>
470 struct scalar_multiple2_op {
471   typedef typename scalar_product_traits<Scalar1,Scalar2>::ReturnType result_type;
472   EIGEN_STRONG_INLINE scalar_multiple2_op(const scalar_multiple2_op& other) : m_other(other.m_other) { }
473   EIGEN_STRONG_INLINE scalar_multiple2_op(const Scalar2& other) : m_other(other) { }
474   EIGEN_STRONG_INLINE result_type operator() (const Scalar1& a) const { return a * m_other; }
475   typename add_const_on_value_type<typename NumTraits<Scalar2>::Nested>::type m_other;
476 };
477 template<typename Scalar1,typename Scalar2>
478 struct functor_traits<scalar_multiple2_op<Scalar1,Scalar2> >
479 { enum { Cost = NumTraits<Scalar1>::MulCost, PacketAccess = false }; };
480 
481 template<typename Scalar, bool IsInteger>
482 struct scalar_quotient1_impl {
483   typedef typename packet_traits<Scalar>::type Packet;
484   // FIXME default copy constructors seems bugged with std::complex<>
485   EIGEN_STRONG_INLINE scalar_quotient1_impl(const scalar_quotient1_impl& other) : m_other(other.m_other) { }
486   EIGEN_STRONG_INLINE scalar_quotient1_impl(const Scalar& other) : m_other(static_cast<Scalar>(1) / other) {}
487   EIGEN_STRONG_INLINE Scalar operator() (const Scalar& a) const { return a * m_other; }
488   EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const
489   { return internal::pmul(a, pset1<Packet>(m_other)); }
490   const Scalar m_other;
491 };
492 template<typename Scalar>
493 struct functor_traits<scalar_quotient1_impl<Scalar,false> >
494 { enum { Cost = NumTraits<Scalar>::MulCost, PacketAccess = packet_traits<Scalar>::HasMul }; };
495 
496 template<typename Scalar>
497 struct scalar_quotient1_impl<Scalar,true> {
498   // FIXME default copy constructors seems bugged with std::complex<>
499   EIGEN_STRONG_INLINE scalar_quotient1_impl(const scalar_quotient1_impl& other) : m_other(other.m_other) { }
500   EIGEN_STRONG_INLINE scalar_quotient1_impl(const Scalar& other) : m_other(other) {}
501   EIGEN_STRONG_INLINE Scalar operator() (const Scalar& a) const { return a / m_other; }
502   typename add_const_on_value_type<typename NumTraits<Scalar>::Nested>::type m_other;
503 };
504 template<typename Scalar>
505 struct functor_traits<scalar_quotient1_impl<Scalar,true> >
506 { enum { Cost = 2 * NumTraits<Scalar>::MulCost, PacketAccess = false }; };
507 
508 /** \internal
509   * \brief Template functor to divide a scalar by a fixed other one
510   *
511   * This functor is used to implement the quotient of a matrix by
512   * a scalar where the scalar type is not necessarily a floating point type.
513   *
514   * \sa class CwiseUnaryOp, MatrixBase::operator/
515   */
516 template<typename Scalar>
517 struct scalar_quotient1_op : scalar_quotient1_impl<Scalar, NumTraits<Scalar>::IsInteger > {
518   EIGEN_STRONG_INLINE scalar_quotient1_op(const Scalar& other)
519     : scalar_quotient1_impl<Scalar, NumTraits<Scalar>::IsInteger >(other) {}
520 };
521 template<typename Scalar>
522 struct functor_traits<scalar_quotient1_op<Scalar> >
523 : functor_traits<scalar_quotient1_impl<Scalar, NumTraits<Scalar>::IsInteger> >
524 {};
525 
526 // nullary functors
527 
528 template<typename Scalar>
529 struct scalar_constant_op {
530   typedef typename packet_traits<Scalar>::type Packet;
531   EIGEN_STRONG_INLINE scalar_constant_op(const scalar_constant_op& other) : m_other(other.m_other) { }
532   EIGEN_STRONG_INLINE scalar_constant_op(const Scalar& other) : m_other(other) { }
533   template<typename Index>
534   EIGEN_STRONG_INLINE const Scalar operator() (Index, Index = 0) const { return m_other; }
535   template<typename Index>
536   EIGEN_STRONG_INLINE const Packet packetOp(Index, Index = 0) const { return internal::pset1<Packet>(m_other); }
537   const Scalar m_other;
538 };
539 template<typename Scalar>
540 struct functor_traits<scalar_constant_op<Scalar> >
541 // FIXME replace this packet test by a safe one
542 { enum { Cost = 1, PacketAccess = packet_traits<Scalar>::Vectorizable, IsRepeatable = true }; };
543 
544 template<typename Scalar> struct scalar_identity_op {
545   EIGEN_EMPTY_STRUCT_CTOR(scalar_identity_op)
546   template<typename Index>
547   EIGEN_STRONG_INLINE const Scalar operator() (Index row, Index col) const { return row==col ? Scalar(1) : Scalar(0); }
548 };
549 template<typename Scalar>
550 struct functor_traits<scalar_identity_op<Scalar> >
551 { enum { Cost = NumTraits<Scalar>::AddCost, PacketAccess = false, IsRepeatable = true }; };
552 
553 template <typename Scalar, bool RandomAccess> struct linspaced_op_impl;
554 
555 // linear access for packet ops:
556 // 1) initialization
557 //   base = [low, ..., low] + ([step, ..., step] * [-size, ..., 0])
558 // 2) each step
559 //   base += [size*step, ..., size*step]
560 template <typename Scalar>
561 struct linspaced_op_impl<Scalar,false>
562 {
563   typedef typename packet_traits<Scalar>::type Packet;
564 
565   linspaced_op_impl(Scalar low, Scalar step) :
566   m_low(low), m_step(step),
567   m_packetStep(pset1<Packet>(packet_traits<Scalar>::size*step)),
568   m_base(padd(pset1<Packet>(low),pmul(pset1<Packet>(step),plset<Scalar>(-packet_traits<Scalar>::size)))) {}
569 
570   template<typename Index>
571   EIGEN_STRONG_INLINE const Scalar operator() (Index i) const { return m_low+i*m_step; }
572   template<typename Index>
573   EIGEN_STRONG_INLINE const Packet packetOp(Index) const { return m_base = padd(m_base,m_packetStep); }
574 
575   const Scalar m_low;
576   const Scalar m_step;
577   const Packet m_packetStep;
578   mutable Packet m_base;
579 };
580 
581 // random access for packet ops:
582 // 1) each step
583 //   [low, ..., low] + ( [step, ..., step] * ( [i, ..., i] + [0, ..., size] ) )
584 template <typename Scalar>
585 struct linspaced_op_impl<Scalar,true>
586 {
587   typedef typename packet_traits<Scalar>::type Packet;
588 
589   linspaced_op_impl(Scalar low, Scalar step) :
590   m_low(low), m_step(step),
591   m_lowPacket(pset1<Packet>(m_low)), m_stepPacket(pset1<Packet>(m_step)), m_interPacket(plset<Scalar>(0)) {}
592 
593   template<typename Index>
594   EIGEN_STRONG_INLINE const Scalar operator() (Index i) const { return m_low+i*m_step; }
595 
596   template<typename Index>
597   EIGEN_STRONG_INLINE const Packet packetOp(Index i) const
598   { return internal::padd(m_lowPacket, pmul(m_stepPacket, padd(pset1<Packet>(i),m_interPacket))); }
599 
600   const Scalar m_low;
601   const Scalar m_step;
602   const Packet m_lowPacket;
603   const Packet m_stepPacket;
604   const Packet m_interPacket;
605 };
606 
607 // ----- Linspace functor ----------------------------------------------------------------
608 
609 // Forward declaration (we default to random access which does not really give
610 // us a speed gain when using packet access but it allows to use the functor in
611 // nested expressions).
612 template <typename Scalar, bool RandomAccess = true> struct linspaced_op;
613 template <typename Scalar, bool RandomAccess> struct functor_traits< linspaced_op<Scalar,RandomAccess> >
614 { enum { Cost = 1, PacketAccess = packet_traits<Scalar>::HasSetLinear, IsRepeatable = true }; };
615 template <typename Scalar, bool RandomAccess> struct linspaced_op
616 {
617   typedef typename packet_traits<Scalar>::type Packet;
618   linspaced_op(Scalar low, Scalar high, int num_steps) : impl((num_steps==1 ? high : low), (num_steps==1 ? Scalar() : (high-low)/(num_steps-1))) {}
619 
620   template<typename Index>
621   EIGEN_STRONG_INLINE const Scalar operator() (Index i) const { return impl(i); }
622 
623   // We need this function when assigning e.g. a RowVectorXd to a MatrixXd since
624   // there row==0 and col is used for the actual iteration.
625   template<typename Index>
626   EIGEN_STRONG_INLINE const Scalar operator() (Index row, Index col) const
627   {
628     eigen_assert(col==0 || row==0);
629     return impl(col + row);
630   }
631 
632   template<typename Index>
633   EIGEN_STRONG_INLINE const Packet packetOp(Index i) const { return impl.packetOp(i); }
634 
635   // We need this function when assigning e.g. a RowVectorXd to a MatrixXd since
636   // there row==0 and col is used for the actual iteration.
637   template<typename Index>
638   EIGEN_STRONG_INLINE const Packet packetOp(Index row, Index col) const
639   {
640     eigen_assert(col==0 || row==0);
641     return impl.packetOp(col + row);
642   }
643 
644   // This proxy object handles the actual required temporaries, the different
645   // implementations (random vs. sequential access) as well as the
646   // correct piping to size 2/4 packet operations.
647   const linspaced_op_impl<Scalar,RandomAccess> impl;
648 };
649 
650 // all functors allow linear access, except scalar_identity_op. So we fix here a quick meta
651 // to indicate whether a functor allows linear access, just always answering 'yes' except for
652 // scalar_identity_op.
653 // FIXME move this to functor_traits adding a functor_default
654 template<typename Functor> struct functor_has_linear_access { enum { ret = 1 }; };
655 template<typename Scalar> struct functor_has_linear_access<scalar_identity_op<Scalar> > { enum { ret = 0 }; };
656 
657 // in CwiseBinaryOp, we require the Lhs and Rhs to have the same scalar type, except for multiplication
658 // where we only require them to have the same _real_ scalar type so one may multiply, say, float by complex<float>.
659 // FIXME move this to functor_traits adding a functor_default
660 template<typename Functor> struct functor_allows_mixing_real_and_complex { enum { ret = 0 }; };
661 template<typename LhsScalar,typename RhsScalar> struct functor_allows_mixing_real_and_complex<scalar_product_op<LhsScalar,RhsScalar> > { enum { ret = 1 }; };
662 template<typename LhsScalar,typename RhsScalar> struct functor_allows_mixing_real_and_complex<scalar_conj_product_op<LhsScalar,RhsScalar> > { enum { ret = 1 }; };
663 
664 
665 /** \internal
666   * \brief Template functor to add a scalar to a fixed other one
667   * \sa class CwiseUnaryOp, Array::operator+
668   */
669 /* If you wonder why doing the pset1() in packetOp() is an optimization check scalar_multiple_op */
670 template<typename Scalar>
671 struct scalar_add_op {
672   typedef typename packet_traits<Scalar>::type Packet;
673   // FIXME default copy constructors seems bugged with std::complex<>
674   inline scalar_add_op(const scalar_add_op& other) : m_other(other.m_other) { }
675   inline scalar_add_op(const Scalar& other) : m_other(other) { }
676   inline Scalar operator() (const Scalar& a) const { return a + m_other; }
677   inline const Packet packetOp(const Packet& a) const
678   { return internal::padd(a, pset1<Packet>(m_other)); }
679   const Scalar m_other;
680 };
681 template<typename Scalar>
682 struct functor_traits<scalar_add_op<Scalar> >
683 { enum { Cost = NumTraits<Scalar>::AddCost, PacketAccess = packet_traits<Scalar>::HasAdd }; };
684 
685 /** \internal
686   * \brief Template functor to compute the square root of a scalar
687   * \sa class CwiseUnaryOp, Cwise::sqrt()
688   */
689 template<typename Scalar> struct scalar_sqrt_op {
690   EIGEN_EMPTY_STRUCT_CTOR(scalar_sqrt_op)
691   inline const Scalar operator() (const Scalar& a) const { return internal::sqrt(a); }
692   typedef typename packet_traits<Scalar>::type Packet;
693   inline Packet packetOp(const Packet& a) const { return internal::psqrt(a); }
694 };
695 template<typename Scalar>
696 struct functor_traits<scalar_sqrt_op<Scalar> >
697 { enum {
698     Cost = 5 * NumTraits<Scalar>::MulCost,
699     PacketAccess = packet_traits<Scalar>::HasSqrt
700   };
701 };
702 
703 /** \internal
704   * \brief Template functor to compute the cosine of a scalar
705   * \sa class CwiseUnaryOp, ArrayBase::cos()
706   */
707 template<typename Scalar> struct scalar_cos_op {
708   EIGEN_EMPTY_STRUCT_CTOR(scalar_cos_op)
709   inline Scalar operator() (const Scalar& a) const { return internal::cos(a); }
710   typedef typename packet_traits<Scalar>::type Packet;
711   inline Packet packetOp(const Packet& a) const { return internal::pcos(a); }
712 };
713 template<typename Scalar>
714 struct functor_traits<scalar_cos_op<Scalar> >
715 {
716   enum {
717     Cost = 5 * NumTraits<Scalar>::MulCost,
718     PacketAccess = packet_traits<Scalar>::HasCos
719   };
720 };
721 
722 /** \internal
723   * \brief Template functor to compute the sine of a scalar
724   * \sa class CwiseUnaryOp, ArrayBase::sin()
725   */
726 template<typename Scalar> struct scalar_sin_op {
727   EIGEN_EMPTY_STRUCT_CTOR(scalar_sin_op)
728   inline const Scalar operator() (const Scalar& a) const { return internal::sin(a); }
729   typedef typename packet_traits<Scalar>::type Packet;
730   inline Packet packetOp(const Packet& a) const { return internal::psin(a); }
731 };
732 template<typename Scalar>
733 struct functor_traits<scalar_sin_op<Scalar> >
734 {
735   enum {
736     Cost = 5 * NumTraits<Scalar>::MulCost,
737     PacketAccess = packet_traits<Scalar>::HasSin
738   };
739 };
740 
741 
742 /** \internal
743   * \brief Template functor to compute the tan of a scalar
744   * \sa class CwiseUnaryOp, ArrayBase::tan()
745   */
746 template<typename Scalar> struct scalar_tan_op {
747   EIGEN_EMPTY_STRUCT_CTOR(scalar_tan_op)
748   inline const Scalar operator() (const Scalar& a) const { return internal::tan(a); }
749   typedef typename packet_traits<Scalar>::type Packet;
750   inline Packet packetOp(const Packet& a) const { return internal::ptan(a); }
751 };
752 template<typename Scalar>
753 struct functor_traits<scalar_tan_op<Scalar> >
754 {
755   enum {
756     Cost = 5 * NumTraits<Scalar>::MulCost,
757     PacketAccess = packet_traits<Scalar>::HasTan
758   };
759 };
760 
761 /** \internal
762   * \brief Template functor to compute the arc cosine of a scalar
763   * \sa class CwiseUnaryOp, ArrayBase::acos()
764   */
765 template<typename Scalar> struct scalar_acos_op {
766   EIGEN_EMPTY_STRUCT_CTOR(scalar_acos_op)
767   inline const Scalar operator() (const Scalar& a) const { return internal::acos(a); }
768   typedef typename packet_traits<Scalar>::type Packet;
769   inline Packet packetOp(const Packet& a) const { return internal::pacos(a); }
770 };
771 template<typename Scalar>
772 struct functor_traits<scalar_acos_op<Scalar> >
773 {
774   enum {
775     Cost = 5 * NumTraits<Scalar>::MulCost,
776     PacketAccess = packet_traits<Scalar>::HasACos
777   };
778 };
779 
780 /** \internal
781   * \brief Template functor to compute the arc sine of a scalar
782   * \sa class CwiseUnaryOp, ArrayBase::asin()
783   */
784 template<typename Scalar> struct scalar_asin_op {
785   EIGEN_EMPTY_STRUCT_CTOR(scalar_asin_op)
786   inline const Scalar operator() (const Scalar& a) const { return internal::asin(a); }
787   typedef typename packet_traits<Scalar>::type Packet;
788   inline Packet packetOp(const Packet& a) const { return internal::pasin(a); }
789 };
790 template<typename Scalar>
791 struct functor_traits<scalar_asin_op<Scalar> >
792 {
793   enum {
794     Cost = 5 * NumTraits<Scalar>::MulCost,
795     PacketAccess = packet_traits<Scalar>::HasASin
796   };
797 };
798 
799 /** \internal
800   * \brief Template functor to raise a scalar to a power
801   * \sa class CwiseUnaryOp, Cwise::pow
802   */
803 template<typename Scalar>
804 struct scalar_pow_op {
805   // FIXME default copy constructors seems bugged with std::complex<>
806   inline scalar_pow_op(const scalar_pow_op& other) : m_exponent(other.m_exponent) { }
807   inline scalar_pow_op(const Scalar& exponent) : m_exponent(exponent) {}
808   inline Scalar operator() (const Scalar& a) const { return internal::pow(a, m_exponent); }
809   const Scalar m_exponent;
810 };
811 template<typename Scalar>
812 struct functor_traits<scalar_pow_op<Scalar> >
813 { enum { Cost = 5 * NumTraits<Scalar>::MulCost, PacketAccess = false }; };
814 
815 /** \internal
816   * \brief Template functor to compute the quotient between a scalar and array entries.
817   * \sa class CwiseUnaryOp, Cwise::inverse()
818   */
819 template<typename Scalar>
820 struct scalar_inverse_mult_op {
821   scalar_inverse_mult_op(const Scalar& other) : m_other(other) {}
822   inline Scalar operator() (const Scalar& a) const { return m_other / a; }
823   template<typename Packet>
824   inline const Packet packetOp(const Packet& a) const
825   { return internal::pdiv(pset1<Packet>(m_other),a); }
826   Scalar m_other;
827 };
828 
829 /** \internal
830   * \brief Template functor to compute the inverse of a scalar
831   * \sa class CwiseUnaryOp, Cwise::inverse()
832   */
833 template<typename Scalar>
834 struct scalar_inverse_op {
835   EIGEN_EMPTY_STRUCT_CTOR(scalar_inverse_op)
836   inline Scalar operator() (const Scalar& a) const { return Scalar(1)/a; }
837   template<typename Packet>
838   inline const Packet packetOp(const Packet& a) const
839   { return internal::pdiv(pset1<Packet>(Scalar(1)),a); }
840 };
841 template<typename Scalar>
842 struct functor_traits<scalar_inverse_op<Scalar> >
843 { enum { Cost = NumTraits<Scalar>::MulCost, PacketAccess = packet_traits<Scalar>::HasDiv }; };
844 
845 /** \internal
846   * \brief Template functor to compute the square of a scalar
847   * \sa class CwiseUnaryOp, Cwise::square()
848   */
849 template<typename Scalar>
850 struct scalar_square_op {
851   EIGEN_EMPTY_STRUCT_CTOR(scalar_square_op)
852   inline Scalar operator() (const Scalar& a) const { return a*a; }
853   template<typename Packet>
854   inline const Packet packetOp(const Packet& a) const
855   { return internal::pmul(a,a); }
856 };
857 template<typename Scalar>
858 struct functor_traits<scalar_square_op<Scalar> >
859 { enum { Cost = NumTraits<Scalar>::MulCost, PacketAccess = packet_traits<Scalar>::HasMul }; };
860 
861 /** \internal
862   * \brief Template functor to compute the cube of a scalar
863   * \sa class CwiseUnaryOp, Cwise::cube()
864   */
865 template<typename Scalar>
866 struct scalar_cube_op {
867   EIGEN_EMPTY_STRUCT_CTOR(scalar_cube_op)
868   inline Scalar operator() (const Scalar& a) const { return a*a*a; }
869   template<typename Packet>
870   inline const Packet packetOp(const Packet& a) const
871   { return internal::pmul(a,pmul(a,a)); }
872 };
873 template<typename Scalar>
874 struct functor_traits<scalar_cube_op<Scalar> >
875 { enum { Cost = 2*NumTraits<Scalar>::MulCost, PacketAccess = packet_traits<Scalar>::HasMul }; };
876 
877 // default functor traits for STL functors:
878 
879 template<typename T>
880 struct functor_traits<std::multiplies<T> >
881 { enum { Cost = NumTraits<T>::MulCost, PacketAccess = false }; };
882 
883 template<typename T>
884 struct functor_traits<std::divides<T> >
885 { enum { Cost = NumTraits<T>::MulCost, PacketAccess = false }; };
886 
887 template<typename T>
888 struct functor_traits<std::plus<T> >
889 { enum { Cost = NumTraits<T>::AddCost, PacketAccess = false }; };
890 
891 template<typename T>
892 struct functor_traits<std::minus<T> >
893 { enum { Cost = NumTraits<T>::AddCost, PacketAccess = false }; };
894 
895 template<typename T>
896 struct functor_traits<std::negate<T> >
897 { enum { Cost = NumTraits<T>::AddCost, PacketAccess = false }; };
898 
899 template<typename T>
900 struct functor_traits<std::logical_or<T> >
901 { enum { Cost = 1, PacketAccess = false }; };
902 
903 template<typename T>
904 struct functor_traits<std::logical_and<T> >
905 { enum { Cost = 1, PacketAccess = false }; };
906 
907 template<typename T>
908 struct functor_traits<std::logical_not<T> >
909 { enum { Cost = 1, PacketAccess = false }; };
910 
911 template<typename T>
912 struct functor_traits<std::greater<T> >
913 { enum { Cost = 1, PacketAccess = false }; };
914 
915 template<typename T>
916 struct functor_traits<std::less<T> >
917 { enum { Cost = 1, PacketAccess = false }; };
918 
919 template<typename T>
920 struct functor_traits<std::greater_equal<T> >
921 { enum { Cost = 1, PacketAccess = false }; };
922 
923 template<typename T>
924 struct functor_traits<std::less_equal<T> >
925 { enum { Cost = 1, PacketAccess = false }; };
926 
927 template<typename T>
928 struct functor_traits<std::equal_to<T> >
929 { enum { Cost = 1, PacketAccess = false }; };
930 
931 template<typename T>
932 struct functor_traits<std::not_equal_to<T> >
933 { enum { Cost = 1, PacketAccess = false }; };
934 
935 template<typename T>
936 struct functor_traits<std::binder2nd<T> >
937 { enum { Cost = functor_traits<T>::Cost, PacketAccess = false }; };
938 
939 template<typename T>
940 struct functor_traits<std::binder1st<T> >
941 { enum { Cost = functor_traits<T>::Cost, PacketAccess = false }; };
942 
943 template<typename T>
944 struct functor_traits<std::unary_negate<T> >
945 { enum { Cost = 1 + functor_traits<T>::Cost, PacketAccess = false }; };
946 
947 template<typename T>
948 struct functor_traits<std::binary_negate<T> >
949 { enum { Cost = 1 + functor_traits<T>::Cost, PacketAccess = false }; };
950 
951 #ifdef EIGEN_STDEXT_SUPPORT
952 
953 template<typename T0,typename T1>
954 struct functor_traits<std::project1st<T0,T1> >
955 { enum { Cost = 0, PacketAccess = false }; };
956 
957 template<typename T0,typename T1>
958 struct functor_traits<std::project2nd<T0,T1> >
959 { enum { Cost = 0, PacketAccess = false }; };
960 
961 template<typename T0,typename T1>
962 struct functor_traits<std::select2nd<std::pair<T0,T1> > >
963 { enum { Cost = 0, PacketAccess = false }; };
964 
965 template<typename T0,typename T1>
966 struct functor_traits<std::select1st<std::pair<T0,T1> > >
967 { enum { Cost = 0, PacketAccess = false }; };
968 
969 template<typename T0,typename T1>
970 struct functor_traits<std::unary_compose<T0,T1> >
971 { enum { Cost = functor_traits<T0>::Cost + functor_traits<T1>::Cost, PacketAccess = false }; };
972 
973 template<typename T0,typename T1,typename T2>
974 struct functor_traits<std::binary_compose<T0,T1,T2> >
975 { enum { Cost = functor_traits<T0>::Cost + functor_traits<T1>::Cost + functor_traits<T2>::Cost, PacketAccess = false }; };
976 
977 #endif // EIGEN_STDEXT_SUPPORT
978 
979 // allow to add new functors and specializations of functor_traits from outside Eigen.
980 // this macro is really needed because functor_traits must be specialized after it is declared but before it is used...
981 #ifdef EIGEN_FUNCTORS_PLUGIN
982 #include EIGEN_FUNCTORS_PLUGIN
983 #endif
984 
985 } // end namespace internal
986 
987 } // end namespace Eigen
988 
989 #endif // EIGEN_FUNCTORS_H
990