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1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com>
5 // Copyright (C) 2008-2011 Gael Guennebaud <gael.guennebaud@inria.fr>
6 //
7 // This Source Code Form is subject to the terms of the Mozilla
8 // Public License v. 2.0. If a copy of the MPL was not distributed
9 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
10 
11 #ifndef EIGEN_GENERAL_PRODUCT_H
12 #define EIGEN_GENERAL_PRODUCT_H
13 
14 namespace Eigen {
15 
16 /** \class GeneralProduct
17   * \ingroup Core_Module
18   *
19   * \brief Expression of the product of two general matrices or vectors
20   *
21   * \param LhsNested the type used to store the left-hand side
22   * \param RhsNested the type used to store the right-hand side
23   * \param ProductMode the type of the product
24   *
25   * This class represents an expression of the product of two general matrices.
26   * We call a general matrix, a dense matrix with full storage. For instance,
27   * This excludes triangular, selfadjoint, and sparse matrices.
28   * It is the return type of the operator* between general matrices. Its template
29   * arguments are determined automatically by ProductReturnType. Therefore,
30   * GeneralProduct should never be used direclty. To determine the result type of a
31   * function which involves a matrix product, use ProductReturnType::Type.
32   *
33   * \sa ProductReturnType, MatrixBase::operator*(const MatrixBase<OtherDerived>&)
34   */
35 template<typename Lhs, typename Rhs, int ProductType = internal::product_type<Lhs,Rhs>::value>
36 class GeneralProduct;
37 
38 enum {
39   Large = 2,
40   Small = 3
41 };
42 
43 namespace internal {
44 
45 template<int Rows, int Cols, int Depth> struct product_type_selector;
46 
47 template<int Size, int MaxSize> struct product_size_category
48 {
49   enum { is_large = MaxSize == Dynamic ||
50                     Size >= EIGEN_CACHEFRIENDLY_PRODUCT_THRESHOLD,
51          value = is_large  ? Large
52                : Size == 1 ? 1
53                            : Small
54   };
55 };
56 
57 template<typename Lhs, typename Rhs> struct product_type
58 {
59   typedef typename remove_all<Lhs>::type _Lhs;
60   typedef typename remove_all<Rhs>::type _Rhs;
61   enum {
62     MaxRows  = _Lhs::MaxRowsAtCompileTime,
63     Rows  = _Lhs::RowsAtCompileTime,
64     MaxCols  = _Rhs::MaxColsAtCompileTime,
65     Cols  = _Rhs::ColsAtCompileTime,
66     MaxDepth = EIGEN_SIZE_MIN_PREFER_FIXED(_Lhs::MaxColsAtCompileTime,
67                                            _Rhs::MaxRowsAtCompileTime),
68     Depth = EIGEN_SIZE_MIN_PREFER_FIXED(_Lhs::ColsAtCompileTime,
69                                         _Rhs::RowsAtCompileTime),
70     LargeThreshold = EIGEN_CACHEFRIENDLY_PRODUCT_THRESHOLD
71   };
72 
73   // the splitting into different lines of code here, introducing the _select enums and the typedef below,
74   // is to work around an internal compiler error with gcc 4.1 and 4.2.
75 private:
76   enum {
77     rows_select = product_size_category<Rows,MaxRows>::value,
78     cols_select = product_size_category<Cols,MaxCols>::value,
79     depth_select = product_size_category<Depth,MaxDepth>::value
80   };
81   typedef product_type_selector<rows_select, cols_select, depth_select> selector;
82 
83 public:
84   enum {
85     value = selector::ret
86   };
87 #ifdef EIGEN_DEBUG_PRODUCT
debugproduct_type88   static void debug()
89   {
90       EIGEN_DEBUG_VAR(Rows);
91       EIGEN_DEBUG_VAR(Cols);
92       EIGEN_DEBUG_VAR(Depth);
93       EIGEN_DEBUG_VAR(rows_select);
94       EIGEN_DEBUG_VAR(cols_select);
95       EIGEN_DEBUG_VAR(depth_select);
96       EIGEN_DEBUG_VAR(value);
97   }
98 #endif
99 };
100 
101 
102 /* The following allows to select the kind of product at compile time
103  * based on the three dimensions of the product.
104  * This is a compile time mapping from {1,Small,Large}^3 -> {product types} */
105 // FIXME I'm not sure the current mapping is the ideal one.
106 template<int M, int N>  struct product_type_selector<M,N,1>              { enum { ret = OuterProduct }; };
107 template<int Depth>     struct product_type_selector<1,    1,    Depth>  { enum { ret = InnerProduct }; };
108 template<>              struct product_type_selector<1,    1,    1>      { enum { ret = InnerProduct }; };
109 template<>              struct product_type_selector<Small,1,    Small>  { enum { ret = CoeffBasedProductMode }; };
110 template<>              struct product_type_selector<1,    Small,Small>  { enum { ret = CoeffBasedProductMode }; };
111 template<>              struct product_type_selector<Small,Small,Small>  { enum { ret = CoeffBasedProductMode }; };
112 template<>              struct product_type_selector<Small, Small, 1>    { enum { ret = LazyCoeffBasedProductMode }; };
113 template<>              struct product_type_selector<Small, Large, 1>    { enum { ret = LazyCoeffBasedProductMode }; };
114 template<>              struct product_type_selector<Large, Small, 1>    { enum { ret = LazyCoeffBasedProductMode }; };
115 template<>              struct product_type_selector<1,    Large,Small>  { enum { ret = CoeffBasedProductMode }; };
116 template<>              struct product_type_selector<1,    Large,Large>  { enum { ret = GemvProduct }; };
117 template<>              struct product_type_selector<1,    Small,Large>  { enum { ret = CoeffBasedProductMode }; };
118 template<>              struct product_type_selector<Large,1,    Small>  { enum { ret = CoeffBasedProductMode }; };
119 template<>              struct product_type_selector<Large,1,    Large>  { enum { ret = GemvProduct }; };
120 template<>              struct product_type_selector<Small,1,    Large>  { enum { ret = CoeffBasedProductMode }; };
121 template<>              struct product_type_selector<Small,Small,Large>  { enum { ret = GemmProduct }; };
122 template<>              struct product_type_selector<Large,Small,Large>  { enum { ret = GemmProduct }; };
123 template<>              struct product_type_selector<Small,Large,Large>  { enum { ret = GemmProduct }; };
124 template<>              struct product_type_selector<Large,Large,Large>  { enum { ret = GemmProduct }; };
125 template<>              struct product_type_selector<Large,Small,Small>  { enum { ret = GemmProduct }; };
126 template<>              struct product_type_selector<Small,Large,Small>  { enum { ret = GemmProduct }; };
127 template<>              struct product_type_selector<Large,Large,Small>  { enum { ret = GemmProduct }; };
128 
129 } // end namespace internal
130 
131 /** \class ProductReturnType
132   * \ingroup Core_Module
133   *
134   * \brief Helper class to get the correct and optimized returned type of operator*
135   *
136   * \param Lhs the type of the left-hand side
137   * \param Rhs the type of the right-hand side
138   * \param ProductMode the type of the product (determined automatically by internal::product_mode)
139   *
140   * This class defines the typename Type representing the optimized product expression
141   * between two matrix expressions. In practice, using ProductReturnType<Lhs,Rhs>::Type
142   * is the recommended way to define the result type of a function returning an expression
143   * which involve a matrix product. The class Product should never be
144   * used directly.
145   *
146   * \sa class Product, MatrixBase::operator*(const MatrixBase<OtherDerived>&)
147   */
148 template<typename Lhs, typename Rhs, int ProductType>
149 struct ProductReturnType
150 {
151   // TODO use the nested type to reduce instanciations ????
152 //   typedef typename internal::nested<Lhs,Rhs::ColsAtCompileTime>::type LhsNested;
153 //   typedef typename internal::nested<Rhs,Lhs::RowsAtCompileTime>::type RhsNested;
154 
155   typedef GeneralProduct<Lhs/*Nested*/, Rhs/*Nested*/, ProductType> Type;
156 };
157 
158 template<typename Lhs, typename Rhs>
159 struct ProductReturnType<Lhs,Rhs,CoeffBasedProductMode>
160 {
161   typedef typename internal::nested<Lhs, Rhs::ColsAtCompileTime, typename internal::plain_matrix_type<Lhs>::type >::type LhsNested;
162   typedef typename internal::nested<Rhs, Lhs::RowsAtCompileTime, typename internal::plain_matrix_type<Rhs>::type >::type RhsNested;
163   typedef CoeffBasedProduct<LhsNested, RhsNested, EvalBeforeAssigningBit | EvalBeforeNestingBit> Type;
164 };
165 
166 template<typename Lhs, typename Rhs>
167 struct ProductReturnType<Lhs,Rhs,LazyCoeffBasedProductMode>
168 {
169   typedef typename internal::nested<Lhs, Rhs::ColsAtCompileTime, typename internal::plain_matrix_type<Lhs>::type >::type LhsNested;
170   typedef typename internal::nested<Rhs, Lhs::RowsAtCompileTime, typename internal::plain_matrix_type<Rhs>::type >::type RhsNested;
171   typedef CoeffBasedProduct<LhsNested, RhsNested, NestByRefBit> Type;
172 };
173 
174 // this is a workaround for sun CC
175 template<typename Lhs, typename Rhs>
176 struct LazyProductReturnType : public ProductReturnType<Lhs,Rhs,LazyCoeffBasedProductMode>
177 {};
178 
179 /***********************************************************************
180 *  Implementation of Inner Vector Vector Product
181 ***********************************************************************/
182 
183 // FIXME : maybe the "inner product" could return a Scalar
184 // instead of a 1x1 matrix ??
185 // Pro: more natural for the user
186 // Cons: this could be a problem if in a meta unrolled algorithm a matrix-matrix
187 // product ends up to a row-vector times col-vector product... To tackle this use
188 // case, we could have a specialization for Block<MatrixType,1,1> with: operator=(Scalar x);
189 
190 namespace internal {
191 
192 template<typename Lhs, typename Rhs>
193 struct traits<GeneralProduct<Lhs,Rhs,InnerProduct> >
194  : traits<Matrix<typename scalar_product_traits<typename Lhs::Scalar, typename Rhs::Scalar>::ReturnType,1,1> >
195 {};
196 
197 }
198 
199 template<typename Lhs, typename Rhs>
200 class GeneralProduct<Lhs, Rhs, InnerProduct>
201   : internal::no_assignment_operator,
202     public Matrix<typename internal::scalar_product_traits<typename Lhs::Scalar, typename Rhs::Scalar>::ReturnType,1,1>
203 {
204     typedef Matrix<typename internal::scalar_product_traits<typename Lhs::Scalar, typename Rhs::Scalar>::ReturnType,1,1> Base;
205   public:
206     GeneralProduct(const Lhs& lhs, const Rhs& rhs)
207     {
208       EIGEN_STATIC_ASSERT((internal::is_same<typename Lhs::RealScalar, typename Rhs::RealScalar>::value),
209         YOU_MIXED_DIFFERENT_NUMERIC_TYPES__YOU_NEED_TO_USE_THE_CAST_METHOD_OF_MATRIXBASE_TO_CAST_NUMERIC_TYPES_EXPLICITLY)
210 
211       Base::coeffRef(0,0) = (lhs.transpose().cwiseProduct(rhs)).sum();
212     }
213 
214     /** Convertion to scalar */
215     operator const typename Base::Scalar() const {
216       return Base::coeff(0,0);
217     }
218 };
219 
220 /***********************************************************************
221 *  Implementation of Outer Vector Vector Product
222 ***********************************************************************/
223 
224 namespace internal {
225 template<int StorageOrder> struct outer_product_selector;
226 
227 template<typename Lhs, typename Rhs>
228 struct traits<GeneralProduct<Lhs,Rhs,OuterProduct> >
229  : traits<ProductBase<GeneralProduct<Lhs,Rhs,OuterProduct>, Lhs, Rhs> >
230 {};
231 
232 }
233 
234 template<typename Lhs, typename Rhs>
235 class GeneralProduct<Lhs, Rhs, OuterProduct>
236   : public ProductBase<GeneralProduct<Lhs,Rhs,OuterProduct>, Lhs, Rhs>
237 {
238   public:
239     EIGEN_PRODUCT_PUBLIC_INTERFACE(GeneralProduct)
240 
241     GeneralProduct(const Lhs& lhs, const Rhs& rhs) : Base(lhs,rhs)
242     {
243       EIGEN_STATIC_ASSERT((internal::is_same<typename Lhs::RealScalar, typename Rhs::RealScalar>::value),
244         YOU_MIXED_DIFFERENT_NUMERIC_TYPES__YOU_NEED_TO_USE_THE_CAST_METHOD_OF_MATRIXBASE_TO_CAST_NUMERIC_TYPES_EXPLICITLY)
245     }
246 
247     template<typename Dest> void scaleAndAddTo(Dest& dest, Scalar alpha) const
248     {
249       internal::outer_product_selector<(int(Dest::Flags)&RowMajorBit) ? RowMajor : ColMajor>::run(*this, dest, alpha);
250     }
251 };
252 
253 namespace internal {
254 
255 template<> struct outer_product_selector<ColMajor> {
256   template<typename ProductType, typename Dest>
257   static EIGEN_DONT_INLINE void run(const ProductType& prod, Dest& dest, typename ProductType::Scalar alpha) {
258     typedef typename Dest::Index Index;
259     // FIXME make sure lhs is sequentially stored
260     // FIXME not very good if rhs is real and lhs complex while alpha is real too
261     const Index cols = dest.cols();
262     for (Index j=0; j<cols; ++j)
263       dest.col(j) += (alpha * prod.rhs().coeff(j)) * prod.lhs();
264   }
265 };
266 
267 template<> struct outer_product_selector<RowMajor> {
268   template<typename ProductType, typename Dest>
269   static EIGEN_DONT_INLINE void run(const ProductType& prod, Dest& dest, typename ProductType::Scalar alpha) {
270     typedef typename Dest::Index Index;
271     // FIXME make sure rhs is sequentially stored
272     // FIXME not very good if lhs is real and rhs complex while alpha is real too
273     const Index rows = dest.rows();
274     for (Index i=0; i<rows; ++i)
275       dest.row(i) += (alpha * prod.lhs().coeff(i)) * prod.rhs();
276   }
277 };
278 
279 } // end namespace internal
280 
281 /***********************************************************************
282 *  Implementation of General Matrix Vector Product
283 ***********************************************************************/
284 
285 /*  According to the shape/flags of the matrix we have to distinghish 3 different cases:
286  *   1 - the matrix is col-major, BLAS compatible and M is large => call fast BLAS-like colmajor routine
287  *   2 - the matrix is row-major, BLAS compatible and N is large => call fast BLAS-like rowmajor routine
288  *   3 - all other cases are handled using a simple loop along the outer-storage direction.
289  *  Therefore we need a lower level meta selector.
290  *  Furthermore, if the matrix is the rhs, then the product has to be transposed.
291  */
292 namespace internal {
293 
294 template<typename Lhs, typename Rhs>
295 struct traits<GeneralProduct<Lhs,Rhs,GemvProduct> >
296  : traits<ProductBase<GeneralProduct<Lhs,Rhs,GemvProduct>, Lhs, Rhs> >
297 {};
298 
299 template<int Side, int StorageOrder, bool BlasCompatible>
300 struct gemv_selector;
301 
302 } // end namespace internal
303 
304 template<typename Lhs, typename Rhs>
305 class GeneralProduct<Lhs, Rhs, GemvProduct>
306   : public ProductBase<GeneralProduct<Lhs,Rhs,GemvProduct>, Lhs, Rhs>
307 {
308   public:
309     EIGEN_PRODUCT_PUBLIC_INTERFACE(GeneralProduct)
310 
311     typedef typename Lhs::Scalar LhsScalar;
312     typedef typename Rhs::Scalar RhsScalar;
313 
314     GeneralProduct(const Lhs& lhs, const Rhs& rhs) : Base(lhs,rhs)
315     {
316 //       EIGEN_STATIC_ASSERT((internal::is_same<typename Lhs::Scalar, typename Rhs::Scalar>::value),
317 //         YOU_MIXED_DIFFERENT_NUMERIC_TYPES__YOU_NEED_TO_USE_THE_CAST_METHOD_OF_MATRIXBASE_TO_CAST_NUMERIC_TYPES_EXPLICITLY)
318     }
319 
320     enum { Side = Lhs::IsVectorAtCompileTime ? OnTheLeft : OnTheRight };
321     typedef typename internal::conditional<int(Side)==OnTheRight,_LhsNested,_RhsNested>::type MatrixType;
322 
323     template<typename Dest> void scaleAndAddTo(Dest& dst, Scalar alpha) const
324     {
325       eigen_assert(m_lhs.rows() == dst.rows() && m_rhs.cols() == dst.cols());
326       internal::gemv_selector<Side,(int(MatrixType::Flags)&RowMajorBit) ? RowMajor : ColMajor,
327                        bool(internal::blas_traits<MatrixType>::HasUsableDirectAccess)>::run(*this, dst, alpha);
328     }
329 };
330 
331 namespace internal {
332 
333 // The vector is on the left => transposition
334 template<int StorageOrder, bool BlasCompatible>
335 struct gemv_selector<OnTheLeft,StorageOrder,BlasCompatible>
336 {
337   template<typename ProductType, typename Dest>
338   static void run(const ProductType& prod, Dest& dest, typename ProductType::Scalar alpha)
339   {
340     Transpose<Dest> destT(dest);
341     enum { OtherStorageOrder = StorageOrder == RowMajor ? ColMajor : RowMajor };
342     gemv_selector<OnTheRight,OtherStorageOrder,BlasCompatible>
343       ::run(GeneralProduct<Transpose<const typename ProductType::_RhsNested>,Transpose<const typename ProductType::_LhsNested>, GemvProduct>
344         (prod.rhs().transpose(), prod.lhs().transpose()), destT, alpha);
345   }
346 };
347 
348 template<typename Scalar,int Size,int MaxSize,bool Cond> struct gemv_static_vector_if;
349 
350 template<typename Scalar,int Size,int MaxSize>
351 struct gemv_static_vector_if<Scalar,Size,MaxSize,false>
352 {
353   EIGEN_STRONG_INLINE  Scalar* data() { eigen_internal_assert(false && "should never be called"); return 0; }
354 };
355 
356 template<typename Scalar,int Size>
357 struct gemv_static_vector_if<Scalar,Size,Dynamic,true>
358 {
359   EIGEN_STRONG_INLINE Scalar* data() { return 0; }
360 };
361 
362 template<typename Scalar,int Size,int MaxSize>
363 struct gemv_static_vector_if<Scalar,Size,MaxSize,true>
364 {
365   #if EIGEN_ALIGN_STATICALLY
366   internal::plain_array<Scalar,EIGEN_SIZE_MIN_PREFER_FIXED(Size,MaxSize),0> m_data;
367   EIGEN_STRONG_INLINE Scalar* data() { return m_data.array; }
368   #else
369   // Some architectures cannot align on the stack,
370   // => let's manually enforce alignment by allocating more data and return the address of the first aligned element.
371   enum {
372     ForceAlignment  = internal::packet_traits<Scalar>::Vectorizable,
373     PacketSize      = internal::packet_traits<Scalar>::size
374   };
375   internal::plain_array<Scalar,EIGEN_SIZE_MIN_PREFER_FIXED(Size,MaxSize)+(ForceAlignment?PacketSize:0),0> m_data;
376   EIGEN_STRONG_INLINE Scalar* data() {
377     return ForceAlignment
378             ? reinterpret_cast<Scalar*>((reinterpret_cast<size_t>(m_data.array) & ~(size_t(15))) + 16)
379             : m_data.array;
380   }
381   #endif
382 };
383 
384 template<> struct gemv_selector<OnTheRight,ColMajor,true>
385 {
386   template<typename ProductType, typename Dest>
387   static inline void run(const ProductType& prod, Dest& dest, typename ProductType::Scalar alpha)
388   {
389     typedef typename ProductType::Index Index;
390     typedef typename ProductType::LhsScalar   LhsScalar;
391     typedef typename ProductType::RhsScalar   RhsScalar;
392     typedef typename ProductType::Scalar      ResScalar;
393     typedef typename ProductType::RealScalar  RealScalar;
394     typedef typename ProductType::ActualLhsType ActualLhsType;
395     typedef typename ProductType::ActualRhsType ActualRhsType;
396     typedef typename ProductType::LhsBlasTraits LhsBlasTraits;
397     typedef typename ProductType::RhsBlasTraits RhsBlasTraits;
398     typedef Map<Matrix<ResScalar,Dynamic,1>, Aligned> MappedDest;
399 
400     ActualLhsType actualLhs = LhsBlasTraits::extract(prod.lhs());
401     ActualRhsType actualRhs = RhsBlasTraits::extract(prod.rhs());
402 
403     ResScalar actualAlpha = alpha * LhsBlasTraits::extractScalarFactor(prod.lhs())
404                                   * RhsBlasTraits::extractScalarFactor(prod.rhs());
405 
406     enum {
407       // FIXME find a way to allow an inner stride on the result if packet_traits<Scalar>::size==1
408       // on, the other hand it is good for the cache to pack the vector anyways...
409       EvalToDestAtCompileTime = Dest::InnerStrideAtCompileTime==1,
410       ComplexByReal = (NumTraits<LhsScalar>::IsComplex) && (!NumTraits<RhsScalar>::IsComplex),
411       MightCannotUseDest = (Dest::InnerStrideAtCompileTime!=1) || ComplexByReal
412     };
413 
414     gemv_static_vector_if<ResScalar,Dest::SizeAtCompileTime,Dest::MaxSizeAtCompileTime,MightCannotUseDest> static_dest;
415 
416     bool alphaIsCompatible = (!ComplexByReal) || (imag(actualAlpha)==RealScalar(0));
417     bool evalToDest = EvalToDestAtCompileTime && alphaIsCompatible;
418 
419     RhsScalar compatibleAlpha = get_factor<ResScalar,RhsScalar>::run(actualAlpha);
420 
421     ei_declare_aligned_stack_constructed_variable(ResScalar,actualDestPtr,dest.size(),
422                                                   evalToDest ? dest.data() : static_dest.data());
423 
424     if(!evalToDest)
425     {
426       #ifdef EIGEN_DENSE_STORAGE_CTOR_PLUGIN
427       int size = dest.size();
428       EIGEN_DENSE_STORAGE_CTOR_PLUGIN
429       #endif
430       if(!alphaIsCompatible)
431       {
432         MappedDest(actualDestPtr, dest.size()).setZero();
433         compatibleAlpha = RhsScalar(1);
434       }
435       else
436         MappedDest(actualDestPtr, dest.size()) = dest;
437     }
438 
439     general_matrix_vector_product
440       <Index,LhsScalar,ColMajor,LhsBlasTraits::NeedToConjugate,RhsScalar,RhsBlasTraits::NeedToConjugate>::run(
441         actualLhs.rows(), actualLhs.cols(),
442         actualLhs.data(), actualLhs.outerStride(),
443         actualRhs.data(), actualRhs.innerStride(),
444         actualDestPtr, 1,
445         compatibleAlpha);
446 
447     if (!evalToDest)
448     {
449       if(!alphaIsCompatible)
450         dest += actualAlpha * MappedDest(actualDestPtr, dest.size());
451       else
452         dest = MappedDest(actualDestPtr, dest.size());
453     }
454   }
455 };
456 
457 template<> struct gemv_selector<OnTheRight,RowMajor,true>
458 {
459   template<typename ProductType, typename Dest>
460   static void run(const ProductType& prod, Dest& dest, typename ProductType::Scalar alpha)
461   {
462     typedef typename ProductType::LhsScalar LhsScalar;
463     typedef typename ProductType::RhsScalar RhsScalar;
464     typedef typename ProductType::Scalar    ResScalar;
465     typedef typename ProductType::Index Index;
466     typedef typename ProductType::ActualLhsType ActualLhsType;
467     typedef typename ProductType::ActualRhsType ActualRhsType;
468     typedef typename ProductType::_ActualRhsType _ActualRhsType;
469     typedef typename ProductType::LhsBlasTraits LhsBlasTraits;
470     typedef typename ProductType::RhsBlasTraits RhsBlasTraits;
471 
472     typename add_const<ActualLhsType>::type actualLhs = LhsBlasTraits::extract(prod.lhs());
473     typename add_const<ActualRhsType>::type actualRhs = RhsBlasTraits::extract(prod.rhs());
474 
475     ResScalar actualAlpha = alpha * LhsBlasTraits::extractScalarFactor(prod.lhs())
476                                   * RhsBlasTraits::extractScalarFactor(prod.rhs());
477 
478     enum {
479       // FIXME find a way to allow an inner stride on the result if packet_traits<Scalar>::size==1
480       // on, the other hand it is good for the cache to pack the vector anyways...
481       DirectlyUseRhs = _ActualRhsType::InnerStrideAtCompileTime==1
482     };
483 
484     gemv_static_vector_if<RhsScalar,_ActualRhsType::SizeAtCompileTime,_ActualRhsType::MaxSizeAtCompileTime,!DirectlyUseRhs> static_rhs;
485 
486     ei_declare_aligned_stack_constructed_variable(RhsScalar,actualRhsPtr,actualRhs.size(),
487         DirectlyUseRhs ? const_cast<RhsScalar*>(actualRhs.data()) : static_rhs.data());
488 
489     if(!DirectlyUseRhs)
490     {
491       #ifdef EIGEN_DENSE_STORAGE_CTOR_PLUGIN
492       int size = actualRhs.size();
493       EIGEN_DENSE_STORAGE_CTOR_PLUGIN
494       #endif
495       Map<typename _ActualRhsType::PlainObject>(actualRhsPtr, actualRhs.size()) = actualRhs;
496     }
497 
498     general_matrix_vector_product
499       <Index,LhsScalar,RowMajor,LhsBlasTraits::NeedToConjugate,RhsScalar,RhsBlasTraits::NeedToConjugate>::run(
500         actualLhs.rows(), actualLhs.cols(),
501         actualLhs.data(), actualLhs.outerStride(),
502         actualRhsPtr, 1,
503         dest.data(), dest.innerStride(),
504         actualAlpha);
505   }
506 };
507 
508 template<> struct gemv_selector<OnTheRight,ColMajor,false>
509 {
510   template<typename ProductType, typename Dest>
511   static void run(const ProductType& prod, Dest& dest, typename ProductType::Scalar alpha)
512   {
513     typedef typename Dest::Index Index;
514     // TODO makes sure dest is sequentially stored in memory, otherwise use a temp
515     const Index size = prod.rhs().rows();
516     for(Index k=0; k<size; ++k)
517       dest += (alpha*prod.rhs().coeff(k)) * prod.lhs().col(k);
518   }
519 };
520 
521 template<> struct gemv_selector<OnTheRight,RowMajor,false>
522 {
523   template<typename ProductType, typename Dest>
524   static void run(const ProductType& prod, Dest& dest, typename ProductType::Scalar alpha)
525   {
526     typedef typename Dest::Index Index;
527     // TODO makes sure rhs is sequentially stored in memory, otherwise use a temp
528     const Index rows = prod.rows();
529     for(Index i=0; i<rows; ++i)
530       dest.coeffRef(i) += alpha * (prod.lhs().row(i).cwiseProduct(prod.rhs().transpose())).sum();
531   }
532 };
533 
534 } // end namespace internal
535 
536 /***************************************************************************
537 * Implementation of matrix base methods
538 ***************************************************************************/
539 
540 /** \returns the matrix product of \c *this and \a other.
541   *
542   * \note If instead of the matrix product you want the coefficient-wise product, see Cwise::operator*().
543   *
544   * \sa lazyProduct(), operator*=(const MatrixBase&), Cwise::operator*()
545   */
546 template<typename Derived>
547 template<typename OtherDerived>
548 inline const typename ProductReturnType<Derived, OtherDerived>::Type
549 MatrixBase<Derived>::operator*(const MatrixBase<OtherDerived> &other) const
550 {
551   // A note regarding the function declaration: In MSVC, this function will sometimes
552   // not be inlined since DenseStorage is an unwindable object for dynamic
553   // matrices and product types are holding a member to store the result.
554   // Thus it does not help tagging this function with EIGEN_STRONG_INLINE.
555   enum {
556     ProductIsValid =  Derived::ColsAtCompileTime==Dynamic
557                    || OtherDerived::RowsAtCompileTime==Dynamic
558                    || int(Derived::ColsAtCompileTime)==int(OtherDerived::RowsAtCompileTime),
559     AreVectors = Derived::IsVectorAtCompileTime && OtherDerived::IsVectorAtCompileTime,
560     SameSizes = EIGEN_PREDICATE_SAME_MATRIX_SIZE(Derived,OtherDerived)
561   };
562   // note to the lost user:
563   //    * for a dot product use: v1.dot(v2)
564   //    * for a coeff-wise product use: v1.cwiseProduct(v2)
565   EIGEN_STATIC_ASSERT(ProductIsValid || !(AreVectors && SameSizes),
566     INVALID_VECTOR_VECTOR_PRODUCT__IF_YOU_WANTED_A_DOT_OR_COEFF_WISE_PRODUCT_YOU_MUST_USE_THE_EXPLICIT_FUNCTIONS)
567   EIGEN_STATIC_ASSERT(ProductIsValid || !(SameSizes && !AreVectors),
568     INVALID_MATRIX_PRODUCT__IF_YOU_WANTED_A_COEFF_WISE_PRODUCT_YOU_MUST_USE_THE_EXPLICIT_FUNCTION)
569   EIGEN_STATIC_ASSERT(ProductIsValid || SameSizes, INVALID_MATRIX_PRODUCT)
570 #ifdef EIGEN_DEBUG_PRODUCT
571   internal::product_type<Derived,OtherDerived>::debug();
572 #endif
573   return typename ProductReturnType<Derived,OtherDerived>::Type(derived(), other.derived());
574 }
575 
576 /** \returns an expression of the matrix product of \c *this and \a other without implicit evaluation.
577   *
578   * The returned product will behave like any other expressions: the coefficients of the product will be
579   * computed once at a time as requested. This might be useful in some extremely rare cases when only
580   * a small and no coherent fraction of the result's coefficients have to be computed.
581   *
582   * \warning This version of the matrix product can be much much slower. So use it only if you know
583   * what you are doing and that you measured a true speed improvement.
584   *
585   * \sa operator*(const MatrixBase&)
586   */
587 template<typename Derived>
588 template<typename OtherDerived>
589 const typename LazyProductReturnType<Derived,OtherDerived>::Type
590 MatrixBase<Derived>::lazyProduct(const MatrixBase<OtherDerived> &other) const
591 {
592   enum {
593     ProductIsValid =  Derived::ColsAtCompileTime==Dynamic
594                    || OtherDerived::RowsAtCompileTime==Dynamic
595                    || int(Derived::ColsAtCompileTime)==int(OtherDerived::RowsAtCompileTime),
596     AreVectors = Derived::IsVectorAtCompileTime && OtherDerived::IsVectorAtCompileTime,
597     SameSizes = EIGEN_PREDICATE_SAME_MATRIX_SIZE(Derived,OtherDerived)
598   };
599   // note to the lost user:
600   //    * for a dot product use: v1.dot(v2)
601   //    * for a coeff-wise product use: v1.cwiseProduct(v2)
602   EIGEN_STATIC_ASSERT(ProductIsValid || !(AreVectors && SameSizes),
603     INVALID_VECTOR_VECTOR_PRODUCT__IF_YOU_WANTED_A_DOT_OR_COEFF_WISE_PRODUCT_YOU_MUST_USE_THE_EXPLICIT_FUNCTIONS)
604   EIGEN_STATIC_ASSERT(ProductIsValid || !(SameSizes && !AreVectors),
605     INVALID_MATRIX_PRODUCT__IF_YOU_WANTED_A_COEFF_WISE_PRODUCT_YOU_MUST_USE_THE_EXPLICIT_FUNCTION)
606   EIGEN_STATIC_ASSERT(ProductIsValid || SameSizes, INVALID_MATRIX_PRODUCT)
607 
608   return typename LazyProductReturnType<Derived,OtherDerived>::Type(derived(), other.derived());
609 }
610 
611 } // end namespace Eigen
612 
613 #endif // EIGEN_PRODUCT_H
614