* Started support for unaligned vectorization.

* Introduce a new highly optimized matrix-matrix product for large
  matrices. The code is still highly experimental and it is activated
  only if you define EIGEN_WIP_PRODUCT at compile time.
  Currently the third dimension of the product must be a factor of
  the packet size (x4 for floats) and the right handed side matrix
  must be column major.
  Moreover, currently c = a*b; actually computes c += a*b !!
  Therefore, the code is provided for experimentation purpose only !
  These limitations will be fixed soon or later to become the default
  product implementation.
This commit is contained in:
Gael Guennebaud
2008-05-05 10:23:29 +00:00
parent 8c6007f80e
commit 46fa4c713f
15 changed files with 663 additions and 79 deletions

496
Eigen/src/Core/ProductWIP.h Normal file
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// This file is part of Eigen, a lightweight C++ template library
// for linear algebra. Eigen itself is part of the KDE project.
//
// Copyright (C) 2006-2008 Benoit Jacob <jacob@math.jussieu.fr>
// Copyright (C) 2008 Gael Guennebaud <g.gael@free.fr>
//
// Eigen is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 3 of the License, or (at your option) any later version.
//
// Alternatively, you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of
// the License, or (at your option) any later version.
//
// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License and a copy of the GNU General Public License along with
// Eigen. If not, see <http://www.gnu.org/licenses/>.
#ifndef EIGEN_PRODUCT_H
#define EIGEN_PRODUCT_H
#ifndef EIGEN_VECTORIZE
#error you must enable vectorization to try this experimental product implementation
#endif
template<int Index, int Size, typename Lhs, typename Rhs>
struct ei_product_unroller
{
static void run(int row, int col, const Lhs& lhs, const Rhs& rhs,
typename Lhs::Scalar &res)
{
ei_product_unroller<Index-1, Size, Lhs, Rhs>::run(row, col, lhs, rhs, res);
res += lhs.coeff(row, Index) * rhs.coeff(Index, col);
}
};
template<int Size, typename Lhs, typename Rhs>
struct ei_product_unroller<0, Size, Lhs, Rhs>
{
static void run(int row, int col, const Lhs& lhs, const Rhs& rhs,
typename Lhs::Scalar &res)
{
res = lhs.coeff(row, 0) * rhs.coeff(0, col);
}
};
template<int Index, typename Lhs, typename Rhs>
struct ei_product_unroller<Index, Dynamic, Lhs, Rhs>
{
static void run(int, int, const Lhs&, const Rhs&, typename Lhs::Scalar&) {}
};
// prevent buggy user code from causing an infinite recursion
template<int Index, typename Lhs, typename Rhs>
struct ei_product_unroller<Index, 0, Lhs, Rhs>
{
static void run(int, int, const Lhs&, const Rhs&, typename Lhs::Scalar&) {}
};
template<bool RowMajor, int Index, int Size, typename Lhs, typename Rhs, typename PacketScalar>
struct ei_packet_product_unroller;
template<int Index, int Size, typename Lhs, typename Rhs, typename PacketScalar>
struct ei_packet_product_unroller<true, Index, Size, Lhs, Rhs, PacketScalar>
{
static void run(int row, int col, const Lhs& lhs, const Rhs& rhs, PacketScalar &res)
{
ei_packet_product_unroller<true, Index-1, Size, Lhs, Rhs, PacketScalar>::run(row, col, lhs, rhs, res);
res = ei_pmadd(ei_pset1(lhs.coeff(row, Index)), rhs.packetCoeff(Index, col), res);
}
};
template<int Index, int Size, typename Lhs, typename Rhs, typename PacketScalar>
struct ei_packet_product_unroller<false, Index, Size, Lhs, Rhs, PacketScalar>
{
static void run(int row, int col, const Lhs& lhs, const Rhs& rhs, PacketScalar &res)
{
ei_packet_product_unroller<false, Index-1, Size, Lhs, Rhs, PacketScalar>::run(row, col, lhs, rhs, res);
res = ei_pmadd(lhs.packetCoeff(row, Index), ei_pset1(rhs.coeff(Index, col)), res);
}
};
template<int Size, typename Lhs, typename Rhs, typename PacketScalar>
struct ei_packet_product_unroller<true, 0, Size, Lhs, Rhs, PacketScalar>
{
static void run(int row, int col, const Lhs& lhs, const Rhs& rhs, PacketScalar &res)
{
res = ei_pmul(ei_pset1(lhs.coeff(row, 0)),rhs.packetCoeff(0, col));
}
};
template<int Size, typename Lhs, typename Rhs, typename PacketScalar>
struct ei_packet_product_unroller<false, 0, Size, Lhs, Rhs, PacketScalar>
{
static void run(int row, int col, const Lhs& lhs, const Rhs& rhs, PacketScalar &res)
{
res = ei_pmul(lhs.packetCoeff(row, 0), ei_pset1(rhs.coeff(0, col)));
}
};
template<bool RowMajor, int Index, typename Lhs, typename Rhs, typename PacketScalar>
struct ei_packet_product_unroller<RowMajor, Index, Dynamic, Lhs, Rhs, PacketScalar>
{
static void run(int, int, const Lhs&, const Rhs&, PacketScalar&) {}
};
template<typename Product, bool RowMajor = true> struct ProductPacketCoeffImpl {
inline static typename Product::PacketScalar execute(const Product& product, int row, int col)
{ return product._packetCoeffRowMajor(row,col); }
};
template<typename Product> struct ProductPacketCoeffImpl<Product, false> {
inline static typename Product::PacketScalar execute(const Product& product, int row, int col)
{ return product._packetCoeffColumnMajor(row,col); }
};
/** \class Product
*
* \brief Expression of the product of two matrices
*
* \param Lhs the type of the left-hand side
* \param Rhs the type of the right-hand side
* \param EvalMode internal use only
*
* This class represents an expression of the product of two matrices.
* It is the return type of the operator* between matrices, and most of the time
* this is the only way it is used.
*
* \sa class Sum, class Difference
*/
template<typename Lhs, typename Rhs> struct ei_product_eval_mode
{
enum{ value = Lhs::MaxRowsAtCompileTime >= EIGEN_CACHEFRIENDLY_PRODUCT_THRESHOLD
&& Rhs::MaxColsAtCompileTime >= EIGEN_CACHEFRIENDLY_PRODUCT_THRESHOLD
&& (!( (Lhs::Flags&RowMajorBit) && ((Rhs::Flags&RowMajorBit) ^ RowMajorBit)))
? CacheOptimalProduct : NormalProduct };
};
template<typename Lhs, typename Rhs, int EvalMode>
struct ei_traits<Product<Lhs, Rhs, EvalMode> >
{
typedef typename Lhs::Scalar Scalar;
typedef typename ei_nested<Lhs,Rhs::ColsAtCompileTime>::type LhsNested;
typedef typename ei_nested<Rhs,Lhs::RowsAtCompileTime>::type RhsNested;
typedef typename ei_unref<LhsNested>::type _LhsNested;
typedef typename ei_unref<RhsNested>::type _RhsNested;
enum {
LhsCoeffReadCost = _LhsNested::CoeffReadCost,
RhsCoeffReadCost = _RhsNested::CoeffReadCost,
LhsFlags = _LhsNested::Flags,
RhsFlags = _RhsNested::Flags,
RowsAtCompileTime = Lhs::RowsAtCompileTime,
ColsAtCompileTime = Rhs::ColsAtCompileTime,
MaxRowsAtCompileTime = Lhs::MaxRowsAtCompileTime,
MaxColsAtCompileTime = Rhs::MaxColsAtCompileTime,
_RhsVectorizable = (RhsFlags & RowMajorBit) && (RhsFlags & VectorizableBit) && (ColsAtCompileTime % ei_packet_traits<Scalar>::size == 0),
_LhsVectorizable = (!(LhsFlags & RowMajorBit)) && (LhsFlags & VectorizableBit) && (RowsAtCompileTime % ei_packet_traits<Scalar>::size == 0),
_Vectorizable = (_LhsVectorizable || _RhsVectorizable) ? 1 : 0,
_RowMajor = (RhsFlags & RowMajorBit)
&& (EvalMode==(int)CacheOptimalProduct ? (int)LhsFlags & RowMajorBit : (!_LhsVectorizable)),
_LostBits = DefaultLostFlagMask & ~(
(_RowMajor ? 0 : RowMajorBit)
| ((RowsAtCompileTime == Dynamic || ColsAtCompileTime == Dynamic) ? 0 : LargeBit)),
Flags = ((unsigned int)(LhsFlags | RhsFlags) & _LostBits)
// | EvalBeforeAssigningBit //FIXME
| EvalBeforeNestingBit
| (_Vectorizable ? VectorizableBit : 0),
CoeffReadCost
= Lhs::ColsAtCompileTime == Dynamic
? Dynamic
: Lhs::ColsAtCompileTime
* (NumTraits<Scalar>::MulCost + LhsCoeffReadCost + RhsCoeffReadCost)
+ (Lhs::ColsAtCompileTime - 1) * NumTraits<Scalar>::AddCost
};
};
template<typename Lhs, typename Rhs, int EvalMode> class Product : ei_no_assignment_operator,
public MatrixBase<Product<Lhs, Rhs, EvalMode> >
{
public:
EIGEN_GENERIC_PUBLIC_INTERFACE(Product)
friend class ProductPacketCoeffImpl<Product,Flags&RowMajorBit>;
typedef typename ei_traits<Product>::LhsNested LhsNested;
typedef typename ei_traits<Product>::RhsNested RhsNested;
typedef typename ei_traits<Product>::_LhsNested _LhsNested;
typedef typename ei_traits<Product>::_RhsNested _RhsNested;
Product(const Lhs& lhs, const Rhs& rhs)
: m_lhs(lhs), m_rhs(rhs)
{
ei_assert(lhs.cols() == rhs.rows());
}
/** \internal */
template<typename DestDerived> void _cacheFriendlyEval(DestDerived& res) const;
private:
int _rows() const { return m_lhs.rows(); }
int _cols() const { return m_rhs.cols(); }
const Scalar _coeff(int row, int col) const
{
Scalar res;
const bool unroll = CoeffReadCost <= EIGEN_UNROLLING_LIMIT;
if(unroll)
{
ei_product_unroller<Lhs::ColsAtCompileTime-1,
unroll ? Lhs::ColsAtCompileTime : Dynamic,
_LhsNested, _RhsNested>
::run(row, col, m_lhs, m_rhs, res);
}
else
{
res = m_lhs.coeff(row, 0) * m_rhs.coeff(0, col);
for(int i = 1; i < m_lhs.cols(); i++)
res += m_lhs.coeff(row, i) * m_rhs.coeff(i, col);
}
return res;
}
template<int LoadMode>
PacketScalar _packetCoeff(int row, int col) const
{
if(Lhs::ColsAtCompileTime <= EIGEN_UNROLLING_LIMIT)
{
PacketScalar res;
ei_packet_product_unroller<Flags&RowMajorBit, Lhs::ColsAtCompileTime-1,
Lhs::ColsAtCompileTime <= EIGEN_UNROLLING_LIMIT
? Lhs::ColsAtCompileTime : Dynamic,
_LhsNested, _RhsNested, PacketScalar>
::run(row, col, m_lhs, m_rhs, res);
return res;
}
else
return ProductPacketCoeffImpl<Product,Flags&RowMajorBit>::execute(*this, row, col);
}
PacketScalar _packetCoeffRowMajor(int row, int col) const
{
PacketScalar res;
res = ei_pmul(ei_pset1(m_lhs.coeff(row, 0)),m_rhs.packetCoeff(0, col));
for(int i = 1; i < m_lhs.cols(); i++)
res = ei_pmadd(ei_pset1(m_lhs.coeff(row, i)), m_rhs.packetCoeff(i, col), res);
return res;
}
PacketScalar _packetCoeffColumnMajor(int row, int col) const
{
PacketScalar res;
res = ei_pmul(m_lhs.packetCoeff(row, 0), ei_pset1(m_rhs.coeff(0, col)));
for(int i = 1; i < m_lhs.cols(); i++)
res = ei_pmadd(m_lhs.packetCoeff(row, i), ei_pset1(m_rhs.coeff(i, col)), res);
return res;
}
protected:
const LhsNested m_lhs;
const RhsNested m_rhs;
};
/** \returns the matrix product of \c *this and \a other.
*
* \note This function causes an immediate evaluation. If you want to perform a matrix product
* without immediate evaluation, call .lazy() on one of the matrices before taking the product.
*
* \sa lazy(), operator*=(const MatrixBase&)
*/
template<typename Derived>
template<typename OtherDerived>
const Product<Derived,OtherDerived>
MatrixBase<Derived>::operator*(const MatrixBase<OtherDerived> &other) const
{
return Product<Derived,OtherDerived>(derived(), other.derived());
}
/** replaces \c *this by \c *this * \a other.
*
* \returns a reference to \c *this
*/
template<typename Derived>
template<typename OtherDerived>
Derived &
MatrixBase<Derived>::operator*=(const MatrixBase<OtherDerived> &other)
{
return *this = *this * other;
}
template<typename Derived>
template<typename Lhs, typename Rhs>
Derived& MatrixBase<Derived>::lazyAssign(const Product<Lhs,Rhs,CacheOptimalProduct>& product)
{
product._cacheFriendlyEval(*this);
return derived();
}
template<typename Lhs, typename Rhs, int EvalMode>
template<typename DestDerived>
void Product<Lhs,Rhs,EvalMode>::_cacheFriendlyEval(DestDerived& res) const
{
// allow direct access to data for benchmark purpose
const Scalar* __restrict__ a = m_lhs.derived().data();
const Scalar* __restrict__ b = m_rhs.derived().data();
Scalar* __restrict__ c = res.derived().data();
// FIXME find a way to optimize: (an_xpr) + (a * b)
// then we don't need to clear res and avoid and additional mat-mat sum
// res.setZero();
const int ps = ei_packet_traits<Scalar>::size; // size of a packet
#if (defined __i386__)
// i386 architectures provides only 8 xmmm register,
// so let's reduce the max number of rows processed at once
const int bw = 4; // number of rows treated at once
#else
const int bw = 8; // number of rows treated at once
#endif
const int bs = ps * bw; // total number of elements treated at once
const int rows = _rows();
const int cols = _cols();
const int size = m_lhs.cols(); // third dimension of the product
const int l2blocksize = 256 > _cols() ? _cols() : 256;
const bool rhsIsAligned = ((size%ps) == 0);
const bool resIsAligned = ((cols%ps) == 0);
Scalar* __restrict__ block = new Scalar[l2blocksize*size];
// loops on each L2 cache friendly blocks of the result
for(int l2i=0; l2i<_rows(); l2i+=l2blocksize)
{
const int l2blockRowEnd = std::min(l2i+l2blocksize, rows);
const int l2blockRowEndBW = l2blockRowEnd & 0xFFFFF8; // end of the rows aligned to bw
const int l2blockRowRemaining = l2blockRowEnd - l2blockRowEndBW; // number of remaining rows
// build a cache friendly block
int count = 0;
// copy l2blocksize rows of m_lhs to blocks of ps x bw
for(int l2k=0; l2k<size; l2k+=l2blocksize)
{
const int l2blockSizeEnd = std::min(l2k+l2blocksize, size);
for (int i = l2i; i<l2blockRowEndBW; i+=bw)
{
for (int k=l2k; k<l2blockSizeEnd; k+=ps)
{
// TODO write these two loops using meta unrolling
// negligible for large matrices but useful for small ones
for (int w=0; w<bw; ++w)
for (int s=0; s<ps; ++s)
block[count++] = m_lhs.coeff(i+w,k+s);
}
}
if (l2blockRowRemaining>0)
{
for (int k=l2k; k<l2blockSizeEnd; k+=ps)
{
for (int w=0; w<l2blockRowRemaining; ++w)
for (int s=0; s<ps; ++s)
block[count++] = m_lhs.coeff(l2blockRowEndBW+w,k+s);
}
}
}
for(int l2j=0; l2j<cols; l2j+=l2blocksize)
{
int l2blockColEnd = std::min(l2j+l2blocksize, cols);
for(int l2k=0; l2k<size; l2k+=l2blocksize)
{
// acumulate a full row of current a block time 4 cols of current a block
// to a 1x4 c block
int l2blockSizeEnd = std::min(l2k+l2blocksize, size);
// for each 4x1 result's block sub blocks...
for(int l1i=l2i; l1i<l2blockRowEndBW; l1i+=bw)
{
for(int l1j=l2j; l1j<l2blockColEnd; l1j+=1)
{
int offsetblock = l2k * (l2blockRowEnd-l2i) + (l1i-l2i)*(l2blockSizeEnd-l2k) - l2k*bw/*bs*/;
const Scalar* localB = &block[offsetblock];
int l1jsize = l1j * size; //TODO find a better way to optimize address computation ?
PacketScalar dst[bw];
dst[0] = ei_pset1(Scalar(0.));
dst[1] = dst[0];
dst[2] = dst[0];
dst[3] = dst[0];
if (bw==8)
{
dst[4] = dst[0];
dst[5] = dst[0];
dst[6] = dst[0];
dst[7] = dst[0];
}
PacketScalar b0, b1, tmp;
// TODO in unaligned mode, preload the next element
// PacketScalar tmp1 = _mm_load_ps(&m_rhs.derived().data()[l1jsize+l2k]);
asm("#eigen begincore");
for(int k=l2k; k<l2blockSizeEnd; k+=ps)
{
//PacketScalar tmp = m_rhs.packetCoeff(k, l1j);
if (rhsIsAligned)
tmp = ei_pload(&m_rhs.derived().data()[l1jsize + k]);
else
tmp = ei_ploadu(&m_rhs.derived().data()[l1jsize + k]);
b0 = ei_pload(&(localB[k*bw]));
b1 = ei_pload(&(localB[k*bw+ps]));
dst[0] = ei_pmadd(tmp, b0, dst[0]);
b0 = ei_pload(&(localB[k*bw+2*ps]));
dst[1] = ei_pmadd(tmp, b1, dst[1]);
b1 = ei_pload(&(localB[k*bw+3*ps]));
dst[2] = ei_pmadd(tmp, b0, dst[2]);
if (bw==8)
b0 = ei_pload(&(localB[k*bw+4*ps]));
dst[3] = ei_pmadd(tmp, b1, dst[3]);
if (bw==8)
{
b1 = ei_pload(&(localB[k*bw+5*ps]));
dst[4] = ei_pmadd(tmp, b0, dst[4]);
b0 = ei_pload(&(localB[k*bw+6*ps]));
dst[5] = ei_pmadd(tmp, b1, dst[5]);
b1 = ei_pload(&(localB[k*bw+7*ps]));
dst[6] = ei_pmadd(tmp, b0, dst[6]);
dst[7] = ei_pmadd(tmp, b1, dst[7]);
}
}
res.template writePacketCoeff<Aligned>(l1i, l1j, ei_padd(res.template packetCoeff<Aligned>(l1i, l1j), ei_predux(dst)));
if (ps==2)
res.template writePacketCoeff<Aligned>(l1i+2,l1j, ei_padd(res.template packetCoeff<Aligned>(l1i+2,l1j), ei_predux(&(dst[2]))));
if (bw==8)
{
res.template writePacketCoeff<Aligned>(l1i+4,l1j, ei_padd(res.template packetCoeff<Aligned>(l1i+4,l1j), ei_predux(&(dst[4]))));
if (ps==2)
res.template writePacketCoeff<Aligned>(l1i+6,l1j, ei_padd(res.template packetCoeff<Aligned>(l1i+6,l1j), ei_predux(&(dst[6]))));
}
asm("#eigen endcore");
}
}
if (l2blockRowRemaining>0)
{
// TODO optimize this part using a generic templated function that processes N rows
// here we process the remaining l2blockRowRemaining rows
for(int l1j=l2j; l1j<l2blockColEnd; l1j+=1)
{
int offsetblock = l2k * (l2blockRowEnd-l2i) + (l2blockRowEndBW-l2i)*(l2blockSizeEnd-l2k) - l2k*l2blockRowRemaining;
const Scalar* localB = &block[offsetblock];
int l1jsize = l1j * size;
PacketScalar dst[bw];
dst[0] = ei_pset1(Scalar(0.));
for (int w = 1; w<l2blockRowRemaining; ++w)
dst[w] = dst[0];
PacketScalar b0, b1, tmp;
asm("#eigen begincore dynamic");
for(int k=l2k; k<l2blockSizeEnd; k+=ps)
{
//PacketScalar tmp = m_rhs.packetCoeff(k, l1j);
if (rhsIsAligned)
tmp = ei_pload(&m_rhs.derived().data()[l1jsize + k]);
else
tmp = ei_ploadu(&m_rhs.derived().data()[l1jsize + k]);
// TODO optimize this loop
for (int w = 0; w<l2blockRowRemaining; ++w)
dst[w] = ei_pmadd(tmp, ei_pload(&(localB[k*l2blockRowRemaining+w*ps])), dst[w]);
}
// TODO optimize this loop
for (int w = 0; w<l2blockRowRemaining; ++w)
res.coeffRef(l2blockRowEndBW+w, l1j) += ei_predux(dst[w]);
asm("#eigen endcore dynamic");
}
}
}
}
}
delete[] block;
}
#endif // EIGEN_PRODUCT_H