1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2008-2009 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_GENERAL_MATRIX_MATRIX_H
11 #define EIGEN_GENERAL_MATRIX_MATRIX_H
12 
13 namespace Eigen {
14 
15 namespace internal {
16 
17 template<typename _LhsScalar, typename _RhsScalar> class level3_blocking;
18 
19 /* Specialization for a row-major destination matrix => simple transposition of the product */
20 template<
21   typename Index,
22   typename LhsScalar, int LhsStorageOrder, bool ConjugateLhs,
23   typename RhsScalar, int RhsStorageOrder, bool ConjugateRhs>
24 struct general_matrix_matrix_product<Index,LhsScalar,LhsStorageOrder,ConjugateLhs,RhsScalar,RhsStorageOrder,ConjugateRhs,RowMajor>
25 {
26   typedef typename scalar_product_traits<LhsScalar, RhsScalar>::ReturnType ResScalar;
27   static EIGEN_STRONG_INLINE void run(
28     Index rows, Index cols, Index depth,
29     const LhsScalar* lhs, Index lhsStride,
30     const RhsScalar* rhs, Index rhsStride,
31     ResScalar* res, Index resStride,
32     ResScalar alpha,
33     level3_blocking<RhsScalar,LhsScalar>& blocking,
34     GemmParallelInfo<Index>* info = 0)
35   {
36     // transpose the product such that the result is column major
37     general_matrix_matrix_product<Index,
38       RhsScalar, RhsStorageOrder==RowMajor ? ColMajor : RowMajor, ConjugateRhs,
39       LhsScalar, LhsStorageOrder==RowMajor ? ColMajor : RowMajor, ConjugateLhs,
40       ColMajor>
41     ::run(cols,rows,depth,rhs,rhsStride,lhs,lhsStride,res,resStride,alpha,blocking,info);
42   }
43 };
44 
45 /*  Specialization for a col-major destination matrix
46  *    => Blocking algorithm following Goto's paper */
47 template<
48   typename Index,
49   typename LhsScalar, int LhsStorageOrder, bool ConjugateLhs,
50   typename RhsScalar, int RhsStorageOrder, bool ConjugateRhs>
51 struct general_matrix_matrix_product<Index,LhsScalar,LhsStorageOrder,ConjugateLhs,RhsScalar,RhsStorageOrder,ConjugateRhs,ColMajor>
52 {
53 
54 typedef typename scalar_product_traits<LhsScalar, RhsScalar>::ReturnType ResScalar;
55 static void run(Index rows, Index cols, Index depth,
56   const LhsScalar* _lhs, Index lhsStride,
57   const RhsScalar* _rhs, Index rhsStride,
58   ResScalar* res, Index resStride,
59   ResScalar alpha,
60   level3_blocking<LhsScalar,RhsScalar>& blocking,
61   GemmParallelInfo<Index>* info = 0)
62 {
63   const_blas_data_mapper<LhsScalar, Index, LhsStorageOrder> lhs(_lhs,lhsStride);
64   const_blas_data_mapper<RhsScalar, Index, RhsStorageOrder> rhs(_rhs,rhsStride);
65 
66   typedef gebp_traits<LhsScalar,RhsScalar> Traits;
67 
68   Index kc = blocking.kc();                   // cache block size along the K direction
69   Index mc = (std::min)(rows,blocking.mc());  // cache block size along the M direction
70   //Index nc = blocking.nc(); // cache block size along the N direction
71 
72   gemm_pack_lhs<LhsScalar, Index, Traits::mr, Traits::LhsProgress, LhsStorageOrder> pack_lhs;
73   gemm_pack_rhs<RhsScalar, Index, Traits::nr, RhsStorageOrder> pack_rhs;
74   gebp_kernel<LhsScalar, RhsScalar, Index, Traits::mr, Traits::nr, ConjugateLhs, ConjugateRhs> gebp;
75 
76 #ifdef EIGEN_HAS_OPENMP
77   if(info)
78   {
79     // this is the parallel version!
80     Index tid = omp_get_thread_num();
81     Index threads = omp_get_num_threads();
82 
83     std::size_t sizeA = kc*mc;
84     std::size_t sizeW = kc*Traits::WorkSpaceFactor;
85     ei_declare_aligned_stack_constructed_variable(LhsScalar, blockA, sizeA, 0);
86     ei_declare_aligned_stack_constructed_variable(RhsScalar, w, sizeW, 0);
87 
88     RhsScalar* blockB = blocking.blockB();
89     eigen_internal_assert(blockB!=0);
90 
91     // For each horizontal panel of the rhs, and corresponding vertical panel of the lhs...
92     for(Index k=0; k<depth; k+=kc)
93     {
94       const Index actual_kc = (std::min)(k+kc,depth)-k; // => rows of B', and cols of the A'
95 
96       // In order to reduce the chance that a thread has to wait for the other,
97       // let's start by packing A'.
98       pack_lhs(blockA, &lhs(0,k), lhsStride, actual_kc, mc);
99 
100       // Pack B_k to B' in a parallel fashion:
101       // each thread packs the sub block B_k,j to B'_j where j is the thread id.
102 
103       // However, before copying to B'_j, we have to make sure that no other thread is still using it,
104       // i.e., we test that info[tid].users equals 0.
105       // Then, we set info[tid].users to the number of threads to mark that all other threads are going to use it.
106       while(info[tid].users!=0) {}
107       info[tid].users += threads;
108 
109       pack_rhs(blockB+info[tid].rhs_start*actual_kc, &rhs(k,info[tid].rhs_start), rhsStride, actual_kc, info[tid].rhs_length);
110 
111       // Notify the other threads that the part B'_j is ready to go.
112       info[tid].sync = k;
113 
114       // Computes C_i += A' * B' per B'_j
115       for(Index shift=0; shift<threads; ++shift)
116       {
117         Index j = (tid+shift)%threads;
118 
119         // At this point we have to make sure that B'_j has been updated by the thread j,
120         // we use testAndSetOrdered to mimic a volatile access.
121         // However, no need to wait for the B' part which has been updated by the current thread!
122         if(shift>0)
123           while(info[j].sync!=k) {}
124 
125         gebp(res+info[j].rhs_start*resStride, resStride, blockA, blockB+info[j].rhs_start*actual_kc, mc, actual_kc, info[j].rhs_length, alpha, -1,-1,0,0, w);
126       }
127 
128       // Then keep going as usual with the remaining A'
129       for(Index i=mc; i<rows; i+=mc)
130       {
131         const Index actual_mc = (std::min)(i+mc,rows)-i;
132 
133         // pack A_i,k to A'
134         pack_lhs(blockA, &lhs(i,k), lhsStride, actual_kc, actual_mc);
135 
136         // C_i += A' * B'
137         gebp(res+i, resStride, blockA, blockB, actual_mc, actual_kc, cols, alpha, -1,-1,0,0, w);
138       }
139 
140       // Release all the sub blocks B'_j of B' for the current thread,
141       // i.e., we simply decrement the number of users by 1
142       for(Index j=0; j<threads; ++j)
143         #pragma omp atomic
144         --(info[j].users);
145     }
146   }
147   else
148 #endif // EIGEN_HAS_OPENMP
149   {
150     EIGEN_UNUSED_VARIABLE(info);
151 
152     // this is the sequential version!
153     std::size_t sizeA = kc*mc;
154     std::size_t sizeB = kc*cols;
155     std::size_t sizeW = kc*Traits::WorkSpaceFactor;
156 
157     ei_declare_aligned_stack_constructed_variable(LhsScalar, blockA, sizeA, blocking.blockA());
158     ei_declare_aligned_stack_constructed_variable(RhsScalar, blockB, sizeB, blocking.blockB());
159     ei_declare_aligned_stack_constructed_variable(RhsScalar, blockW, sizeW, blocking.blockW());
160 
161     // For each horizontal panel of the rhs, and corresponding panel of the lhs...
162     // (==GEMM_VAR1)
163     for(Index k2=0; k2<depth; k2+=kc)
164     {
165       const Index actual_kc = (std::min)(k2+kc,depth)-k2;
166 
167       // OK, here we have selected one horizontal panel of rhs and one vertical panel of lhs.
168       // => Pack rhs's panel into a sequential chunk of memory (L2 caching)
169       // Note that this panel will be read as many times as the number of blocks in the lhs's
170       // vertical panel which is, in practice, a very low number.
171       pack_rhs(blockB, &rhs(k2,0), rhsStride, actual_kc, cols);
172 
173       // For each mc x kc block of the lhs's vertical panel...
174       // (==GEPP_VAR1)
175       for(Index i2=0; i2<rows; i2+=mc)
176       {
177         const Index actual_mc = (std::min)(i2+mc,rows)-i2;
178 
179         // We pack the lhs's block into a sequential chunk of memory (L1 caching)
180         // Note that this block will be read a very high number of times, which is equal to the number of
181         // micro vertical panel of the large rhs's panel (e.g., cols/4 times).
182         pack_lhs(blockA, &lhs(i2,k2), lhsStride, actual_kc, actual_mc);
183 
184         // Everything is packed, we can now call the block * panel kernel:
185         gebp(res+i2, resStride, blockA, blockB, actual_mc, actual_kc, cols, alpha, -1, -1, 0, 0, blockW);
186       }
187     }
188   }
189 }
190 
191 };
192 
193 /*********************************************************************************
194 *  Specialization of GeneralProduct<> for "large" GEMM, i.e.,
195 *  implementation of the high level wrapper to general_matrix_matrix_product
196 **********************************************************************************/
197 
198 template<typename Lhs, typename Rhs>
199 struct traits<GeneralProduct<Lhs,Rhs,GemmProduct> >
200  : traits<ProductBase<GeneralProduct<Lhs,Rhs,GemmProduct>, Lhs, Rhs> >
201 {};
202 
203 template<typename Scalar, typename Index, typename Gemm, typename Lhs, typename Rhs, typename Dest, typename BlockingType>
204 struct gemm_functor
205 {
206   gemm_functor(const Lhs& lhs, const Rhs& rhs, Dest& dest, const Scalar& actualAlpha,
207                   BlockingType& blocking)
208     : m_lhs(lhs), m_rhs(rhs), m_dest(dest), m_actualAlpha(actualAlpha), m_blocking(blocking)
209   {}
210 
211   void initParallelSession() const
212   {
213     m_blocking.allocateB();
214   }
215 
216   void operator() (Index row, Index rows, Index col=0, Index cols=-1, GemmParallelInfo<Index>* info=0) const
217   {
218     if(cols==-1)
219       cols = m_rhs.cols();
220 
221     Gemm::run(rows, cols, m_lhs.cols(),
222               /*(const Scalar*)*/&m_lhs.coeffRef(row,0), m_lhs.outerStride(),
223               /*(const Scalar*)*/&m_rhs.coeffRef(0,col), m_rhs.outerStride(),
224               (Scalar*)&(m_dest.coeffRef(row,col)), m_dest.outerStride(),
225               m_actualAlpha, m_blocking, info);
226   }
227 
228   protected:
229     const Lhs& m_lhs;
230     const Rhs& m_rhs;
231     Dest& m_dest;
232     Scalar m_actualAlpha;
233     BlockingType& m_blocking;
234 };
235 
236 template<int StorageOrder, typename LhsScalar, typename RhsScalar, int MaxRows, int MaxCols, int MaxDepth, int KcFactor=1,
237 bool FiniteAtCompileTime = MaxRows!=Dynamic && MaxCols!=Dynamic && MaxDepth != Dynamic> class gemm_blocking_space;
238 
239 template<typename _LhsScalar, typename _RhsScalar>
240 class level3_blocking
241 {
242     typedef _LhsScalar LhsScalar;
243     typedef _RhsScalar RhsScalar;
244 
245   protected:
246     LhsScalar* m_blockA;
247     RhsScalar* m_blockB;
248     RhsScalar* m_blockW;
249 
250     DenseIndex m_mc;
251     DenseIndex m_nc;
252     DenseIndex m_kc;
253 
254   public:
255 
256     level3_blocking()
257       : m_blockA(0), m_blockB(0), m_blockW(0), m_mc(0), m_nc(0), m_kc(0)
258     {}
259 
260     inline DenseIndex mc() const { return m_mc; }
261     inline DenseIndex nc() const { return m_nc; }
262     inline DenseIndex kc() const { return m_kc; }
263 
264     inline LhsScalar* blockA() { return m_blockA; }
265     inline RhsScalar* blockB() { return m_blockB; }
266     inline RhsScalar* blockW() { return m_blockW; }
267 };
268 
269 template<int StorageOrder, typename _LhsScalar, typename _RhsScalar, int MaxRows, int MaxCols, int MaxDepth, int KcFactor>
270 class gemm_blocking_space<StorageOrder,_LhsScalar,_RhsScalar,MaxRows, MaxCols, MaxDepth, KcFactor, true>
271   : public level3_blocking<
272       typename conditional<StorageOrder==RowMajor,_RhsScalar,_LhsScalar>::type,
273       typename conditional<StorageOrder==RowMajor,_LhsScalar,_RhsScalar>::type>
274 {
275     enum {
276       Transpose = StorageOrder==RowMajor,
277       ActualRows = Transpose ? MaxCols : MaxRows,
278       ActualCols = Transpose ? MaxRows : MaxCols
279     };
280     typedef typename conditional<Transpose,_RhsScalar,_LhsScalar>::type LhsScalar;
281     typedef typename conditional<Transpose,_LhsScalar,_RhsScalar>::type RhsScalar;
282     typedef gebp_traits<LhsScalar,RhsScalar> Traits;
283     enum {
284       SizeA = ActualRows * MaxDepth,
285       SizeB = ActualCols * MaxDepth,
286       SizeW = MaxDepth * Traits::WorkSpaceFactor
287     };
288 
289     EIGEN_ALIGN16 LhsScalar m_staticA[SizeA];
290     EIGEN_ALIGN16 RhsScalar m_staticB[SizeB];
291     EIGEN_ALIGN16 RhsScalar m_staticW[SizeW];
292 
293   public:
294 
295     gemm_blocking_space(DenseIndex /*rows*/, DenseIndex /*cols*/, DenseIndex /*depth*/)
296     {
297       this->m_mc = ActualRows;
298       this->m_nc = ActualCols;
299       this->m_kc = MaxDepth;
300       this->m_blockA = m_staticA;
301       this->m_blockB = m_staticB;
302       this->m_blockW = m_staticW;
303     }
304 
305     inline void allocateA() {}
306     inline void allocateB() {}
307     inline void allocateW() {}
308     inline void allocateAll() {}
309 };
310 
311 template<int StorageOrder, typename _LhsScalar, typename _RhsScalar, int MaxRows, int MaxCols, int MaxDepth, int KcFactor>
312 class gemm_blocking_space<StorageOrder,_LhsScalar,_RhsScalar,MaxRows, MaxCols, MaxDepth, KcFactor, false>
313   : public level3_blocking<
314       typename conditional<StorageOrder==RowMajor,_RhsScalar,_LhsScalar>::type,
315       typename conditional<StorageOrder==RowMajor,_LhsScalar,_RhsScalar>::type>
316 {
317     enum {
318       Transpose = StorageOrder==RowMajor
319     };
320     typedef typename conditional<Transpose,_RhsScalar,_LhsScalar>::type LhsScalar;
321     typedef typename conditional<Transpose,_LhsScalar,_RhsScalar>::type RhsScalar;
322     typedef gebp_traits<LhsScalar,RhsScalar> Traits;
323 
324     DenseIndex m_sizeA;
325     DenseIndex m_sizeB;
326     DenseIndex m_sizeW;
327 
328   public:
329 
330     gemm_blocking_space(DenseIndex rows, DenseIndex cols, DenseIndex depth)
331     {
332       this->m_mc = Transpose ? cols : rows;
333       this->m_nc = Transpose ? rows : cols;
334       this->m_kc = depth;
335 
336       computeProductBlockingSizes<LhsScalar,RhsScalar,KcFactor>(this->m_kc, this->m_mc, this->m_nc);
337       m_sizeA = this->m_mc * this->m_kc;
338       m_sizeB = this->m_kc * this->m_nc;
339       m_sizeW = this->m_kc*Traits::WorkSpaceFactor;
340     }
341 
342     void allocateA()
343     {
344       if(this->m_blockA==0)
345         this->m_blockA = aligned_new<LhsScalar>(m_sizeA);
346     }
347 
348     void allocateB()
349     {
350       if(this->m_blockB==0)
351         this->m_blockB = aligned_new<RhsScalar>(m_sizeB);
352     }
353 
354     void allocateW()
355     {
356       if(this->m_blockW==0)
357         this->m_blockW = aligned_new<RhsScalar>(m_sizeW);
358     }
359 
360     void allocateAll()
361     {
362       allocateA();
363       allocateB();
364       allocateW();
365     }
366 
367     ~gemm_blocking_space()
368     {
369       aligned_delete(this->m_blockA, m_sizeA);
370       aligned_delete(this->m_blockB, m_sizeB);
371       aligned_delete(this->m_blockW, m_sizeW);
372     }
373 };
374 
375 } // end namespace internal
376 
377 template<typename Lhs, typename Rhs>
378 class GeneralProduct<Lhs, Rhs, GemmProduct>
379   : public ProductBase<GeneralProduct<Lhs,Rhs,GemmProduct>, Lhs, Rhs>
380 {
381     enum {
382       MaxDepthAtCompileTime = EIGEN_SIZE_MIN_PREFER_FIXED(Lhs::MaxColsAtCompileTime,Rhs::MaxRowsAtCompileTime)
383     };
384   public:
385     EIGEN_PRODUCT_PUBLIC_INTERFACE(GeneralProduct)
386 
387     typedef typename  Lhs::Scalar LhsScalar;
388     typedef typename  Rhs::Scalar RhsScalar;
389     typedef           Scalar      ResScalar;
390 
391     GeneralProduct(const Lhs& lhs, const Rhs& rhs) : Base(lhs,rhs)
392     {
393       typedef internal::scalar_product_op<LhsScalar,RhsScalar> BinOp;
394       EIGEN_CHECK_BINARY_COMPATIBILIY(BinOp,LhsScalar,RhsScalar);
395     }
396 
397     template<typename Dest> void scaleAndAddTo(Dest& dst, const Scalar& alpha) const
398     {
399       eigen_assert(dst.rows()==m_lhs.rows() && dst.cols()==m_rhs.cols());
400 
401       typename internal::add_const_on_value_type<ActualLhsType>::type lhs = LhsBlasTraits::extract(m_lhs);
402       typename internal::add_const_on_value_type<ActualRhsType>::type rhs = RhsBlasTraits::extract(m_rhs);
403 
404       Scalar actualAlpha = alpha * LhsBlasTraits::extractScalarFactor(m_lhs)
405                                  * RhsBlasTraits::extractScalarFactor(m_rhs);
406 
407       typedef internal::gemm_blocking_space<(Dest::Flags&RowMajorBit) ? RowMajor : ColMajor,LhsScalar,RhsScalar,
408               Dest::MaxRowsAtCompileTime,Dest::MaxColsAtCompileTime,MaxDepthAtCompileTime> BlockingType;
409 
410       typedef internal::gemm_functor<
411         Scalar, Index,
412         internal::general_matrix_matrix_product<
413           Index,
414           LhsScalar, (_ActualLhsType::Flags&RowMajorBit) ? RowMajor : ColMajor, bool(LhsBlasTraits::NeedToConjugate),
415           RhsScalar, (_ActualRhsType::Flags&RowMajorBit) ? RowMajor : ColMajor, bool(RhsBlasTraits::NeedToConjugate),
416           (Dest::Flags&RowMajorBit) ? RowMajor : ColMajor>,
417         _ActualLhsType, _ActualRhsType, Dest, BlockingType> GemmFunctor;
418 
419       BlockingType blocking(dst.rows(), dst.cols(), lhs.cols());
420 
421       internal::parallelize_gemm<(Dest::MaxRowsAtCompileTime>32 || Dest::MaxRowsAtCompileTime==Dynamic)>(GemmFunctor(lhs, rhs, dst, actualAlpha, blocking), this->rows(), this->cols(), Dest::Flags&RowMajorBit);
422     }
423 };
424 
425 } // end namespace Eigen
426 
427 #endif // EIGEN_GENERAL_MATRIX_MATRIX_H
428