eigen/Eigen/src/Core/CacheFriendlyProduct.h
Gael Guennebaud 64169389ed added an *optional* Eigen2 dynamic library.
it allows the possiblity to save some compilation time by linking to it
*and* defining the token EIGEN_EXTERN_INSTANCIATIONS
2008-05-31 23:21:49 +00:00

353 lines
13 KiB
C++

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra. Eigen itself is part of the KDE project.
//
// 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_CACHE_FRIENDLY_PRODUCT_H
#define EIGEN_CACHE_FRIENDLY_PRODUCT_H
template<typename Scalar>
static void ei_cache_friendly_product(
int _rows, int _cols, int depth,
bool _lhsRowMajor, const Scalar* _lhs, int _lhsStride,
bool _rhsRowMajor, const Scalar* _rhs, int _rhsStride,
bool resRowMajor, Scalar* res, int resStride)
{
const Scalar* __restrict__ lhs;
const Scalar* __restrict__ rhs;
int lhsStride, rhsStride, rows, cols;
bool lhsRowMajor;
if (resRowMajor)
{
lhs = _rhs;
rhs = _lhs;
lhsStride = _rhsStride;
rhsStride = _lhsStride;
cols = _rows;
rows = _cols;
lhsRowMajor = !_rhsRowMajor;
ei_assert(_lhsRowMajor);
}
else
{
lhs = _lhs;
rhs = _rhs;
lhsStride = _lhsStride;
rhsStride = _rhsStride;
rows = _rows;
cols = _cols;
lhsRowMajor = _lhsRowMajor;
ei_assert(!_rhsRowMajor);
}
typedef typename ei_packet_traits<Scalar>::type PacketType;
enum {
PacketSize = sizeof(PacketType)/sizeof(Scalar),
#if (defined __i386__)
// i386 architecture provides only 8 xmm registers,
// so let's reduce the max number of rows processed at once.
MaxBlockRows = 4,
MaxBlockRows_ClampingMask = 0xFFFFFC,
#else
MaxBlockRows = 8,
MaxBlockRows_ClampingMask = 0xFFFFF8,
#endif
// maximal size of the blocks fitted in L2 cache
MaxL2BlockSize = EIGEN_TUNE_FOR_L2_CACHE_SIZE / sizeof(Scalar)
};
//const bool rhsIsAligned = (PacketSize==1) || (((rhsStride%PacketSize) == 0) && (size_t(rhs)%16==0));
const bool resIsAligned = (PacketSize==1) || (((resStride%PacketSize) == 0) && (size_t(res)%16==0));
const int remainingSize = depth % PacketSize;
const int size = depth - remainingSize; // third dimension of the product clamped to packet boundaries
const int l2BlockRows = MaxL2BlockSize > rows ? rows : MaxL2BlockSize;
const int l2BlockCols = MaxL2BlockSize > cols ? cols : MaxL2BlockSize;
const int l2BlockSize = MaxL2BlockSize > size ? size : MaxL2BlockSize;
Scalar* __restrict__ block = (Scalar*)alloca(sizeof(Scalar)*l2BlockRows*size);
Scalar* __restrict__ rhsCopy = (Scalar*)alloca(sizeof(Scalar)*l2BlockSize);
// loops on each L2 cache friendly blocks of the result
for(int l2i=0; l2i<rows; l2i+=l2BlockRows)
{
const int l2blockRowEnd = std::min(l2i+l2BlockRows, rows);
const int l2blockRowEndBW = l2blockRowEnd & MaxBlockRows_ClampingMask; // end of the rows aligned to bw
const int l2blockRemainingRows = l2blockRowEnd - l2blockRowEndBW; // number of remaining rows
//const int l2blockRowEndBWPlusOne = l2blockRowEndBW + (l2blockRemainingRows?0:MaxBlockRows);
// build a cache friendly blocky matrix
int count = 0;
// copy l2blocksize rows of m_lhs to blocks of ps x bw
asm("#eigen begin buildblocks");
for(int l2k=0; l2k<size; l2k+=l2BlockSize)
{
const int l2blockSizeEnd = std::min(l2k+l2BlockSize, size);
for (int i = l2i; i<l2blockRowEndBW/*PlusOne*/; i+=MaxBlockRows)
{
// TODO merge the if l2blockRemainingRows
// const int blockRows = std::min(i+MaxBlockRows, rows) - i;
for (int k=l2k; k<l2blockSizeEnd; k+=PacketSize)
{
// TODO write these loops using meta unrolling
// negligible for large matrices but useful for small ones
if (lhsRowMajor)
{
for (int w=0; w<MaxBlockRows; ++w)
for (int s=0; s<PacketSize; ++s)
block[count++] = lhs[(i+w)*lhsStride + (k+s)];
}
else
{
for (int w=0; w<MaxBlockRows; ++w)
for (int s=0; s<PacketSize; ++s)
block[count++] = lhs[(i+w) + (k+s)*lhsStride];
}
}
}
if (l2blockRemainingRows>0)
{
for (int k=l2k; k<l2blockSizeEnd; k+=PacketSize)
{
if (lhsRowMajor)
{
for (int w=0; w<l2blockRemainingRows; ++w)
for (int s=0; s<PacketSize; ++s)
block[count++] = lhs[(l2blockRowEndBW+w)*lhsStride + (k+s)];
}
else
{
for (int w=0; w<l2blockRemainingRows; ++w)
for (int s=0; s<PacketSize; ++s)
block[count++] = lhs[(l2blockRowEndBW+w) + (k+s)*lhsStride];
}
}
}
}
asm("#eigen end buildblocks");
for(int l2j=0; l2j<cols; l2j+=l2BlockCols)
{
int l2blockColEnd = std::min(l2j+l2BlockCols, cols);
for(int l2k=0; l2k<size; l2k+=l2BlockSize)
{
// acumulate bw rows of lhs time a single column of rhs to a bw x 1 block of res
int l2blockSizeEnd = std::min(l2k+l2BlockSize, size);
// for each bw x 1 result's block
for(int l1i=l2i; l1i<l2blockRowEndBW; l1i+=MaxBlockRows)
{
for(int l1j=l2j; l1j<l2blockColEnd; l1j+=1)
{
int offsetblock = l2k * (l2blockRowEnd-l2i) + (l1i-l2i)*(l2blockSizeEnd-l2k) - l2k*MaxBlockRows;
const Scalar* __restrict__ localB = &block[offsetblock];
const Scalar* __restrict__ rhsColumn = &(rhs[l1j*rhsStride]);
// copy unaligned rhs data
// YES it seems to be faster to copy some part of rhs multiple times
// to aligned memory rather than using unligned load.
// Moreover this avoids a "if" in the most nested loop :)
if (PacketSize>1 && size_t(rhsColumn)%16)
{
int count = 0;
for (int k = l2k; k<l2blockSizeEnd; ++k)
{
rhsCopy[count++] = rhsColumn[k];
}
rhsColumn = &(rhsCopy[-l2k]);
}
PacketType dst[MaxBlockRows];
dst[0] = ei_pset1(Scalar(0.));
dst[1] = dst[0];
dst[2] = dst[0];
dst[3] = dst[0];
if (MaxBlockRows==8)
{
dst[4] = dst[0];
dst[5] = dst[0];
dst[6] = dst[0];
dst[7] = dst[0];
}
PacketType tmp;
asm("#eigen begincore");
for(int k=l2k; k<l2blockSizeEnd; k+=PacketSize)
{
tmp = ei_pload(&rhsColumn[k]);
dst[0] = ei_pmadd(tmp, ei_pload(&(localB[k*MaxBlockRows ])), dst[0]);
dst[1] = ei_pmadd(tmp, ei_pload(&(localB[k*MaxBlockRows+ PacketSize])), dst[1]);
dst[2] = ei_pmadd(tmp, ei_pload(&(localB[k*MaxBlockRows+2*PacketSize])), dst[2]);
dst[3] = ei_pmadd(tmp, ei_pload(&(localB[k*MaxBlockRows+3*PacketSize])), dst[3]);
if (MaxBlockRows==8)
{
dst[4] = ei_pmadd(tmp, ei_pload(&(localB[k*MaxBlockRows+4*PacketSize])), dst[4]);
dst[5] = ei_pmadd(tmp, ei_pload(&(localB[k*MaxBlockRows+5*PacketSize])), dst[5]);
dst[6] = ei_pmadd(tmp, ei_pload(&(localB[k*MaxBlockRows+6*PacketSize])), dst[6]);
dst[7] = ei_pmadd(tmp, ei_pload(&(localB[k*MaxBlockRows+7*PacketSize])), dst[7]);
}
}
Scalar* __restrict__ localRes = &(res[l1i + l1j*resStride]);
if (PacketSize>1 && resIsAligned)
{
ei_pstore(&(localRes[0]), ei_padd(ei_pload(&(localRes[0])), ei_preduxp(dst)));
if (PacketSize==2)
ei_pstore(&(localRes[2]), ei_padd(ei_pload(&(localRes[2])), ei_preduxp(&(dst[2]))));
if (MaxBlockRows==8)
{
ei_pstore(&(localRes[4]), ei_padd(ei_pload(&(localRes[4])), ei_preduxp(&(dst[4]))));
if (PacketSize==2)
ei_pstore(&(localRes[6]), ei_padd(ei_pload(&(localRes[6])), ei_preduxp(&(dst[6]))));
}
}
else
{
localRes[0] += ei_predux(dst[0]);
localRes[1] += ei_predux(dst[1]);
localRes[2] += ei_predux(dst[2]);
localRes[3] += ei_predux(dst[3]);
if (MaxBlockRows==8)
{
localRes[4] += ei_predux(dst[4]);
localRes[5] += ei_predux(dst[5]);
localRes[6] += ei_predux(dst[6]);
localRes[7] += ei_predux(dst[7]);
}
}
asm("#eigen endcore");
}
}
if (l2blockRemainingRows>0)
{
int offsetblock = l2k * (l2blockRowEnd-l2i) + (l2blockRowEndBW-l2i)*(l2blockSizeEnd-l2k) - l2k*l2blockRemainingRows;
const Scalar* localB = &block[offsetblock];
asm("#eigen begin dynkernel");
for(int l1j=l2j; l1j<l2blockColEnd; l1j+=1)
{
const Scalar* __restrict__ rhsColumn = &(rhs[l1j*rhsStride]);
// copy unaligned rhs data
if (PacketSize>1 && size_t(rhsColumn)%16)
{
int count = 0;
for (int k = l2k; k<l2blockSizeEnd; ++k)
{
rhsCopy[count++] = rhsColumn[k];
}
rhsColumn = &(rhsCopy[-l2k]);
}
PacketType dst[MaxBlockRows];
dst[0] = ei_pset1(Scalar(0.));
dst[1] = dst[0];
dst[2] = dst[0];
dst[3] = dst[0];
if (MaxBlockRows>4)
{
dst[4] = dst[0];
dst[5] = dst[0];
dst[6] = dst[0];
dst[7] = dst[0];
}
// let's declare a few other temporary registers
PacketType tmp;
for(int k=l2k; k<l2blockSizeEnd; k+=PacketSize)
{
tmp = ei_pload(&rhsColumn[k]);
dst[0] = ei_pmadd(tmp, ei_pload(&(localB[k*l2blockRemainingRows ])), dst[0]);
if (l2blockRemainingRows>=2) dst[1] = ei_pmadd(tmp, ei_pload(&(localB[k*l2blockRemainingRows+ PacketSize])), dst[1]);
if (l2blockRemainingRows>=3) dst[2] = ei_pmadd(tmp, ei_pload(&(localB[k*l2blockRemainingRows+2*PacketSize])), dst[2]);
if (l2blockRemainingRows>=4) dst[3] = ei_pmadd(tmp, ei_pload(&(localB[k*l2blockRemainingRows+3*PacketSize])), dst[3]);
if (MaxBlockRows>4)
{
if (l2blockRemainingRows>=5) dst[4] = ei_pmadd(tmp, ei_pload(&(localB[k*l2blockRemainingRows+4*PacketSize])), dst[4]);
if (l2blockRemainingRows>=6) dst[5] = ei_pmadd(tmp, ei_pload(&(localB[k*l2blockRemainingRows+5*PacketSize])), dst[5]);
if (l2blockRemainingRows>=7) dst[6] = ei_pmadd(tmp, ei_pload(&(localB[k*l2blockRemainingRows+6*PacketSize])), dst[6]);
if (l2blockRemainingRows>=8) dst[7] = ei_pmadd(tmp, ei_pload(&(localB[k*l2blockRemainingRows+7*PacketSize])), dst[7]);
}
}
Scalar* __restrict__ localRes = &(res[l2blockRowEndBW + l1j*resStride]);
// process the remaining rows once at a time
localRes[0] += ei_predux(dst[0]);
if (l2blockRemainingRows>=2) localRes[1] += ei_predux(dst[1]);
if (l2blockRemainingRows>=3) localRes[2] += ei_predux(dst[2]);
if (l2blockRemainingRows>=4) localRes[3] += ei_predux(dst[3]);
if (MaxBlockRows>4)
{
if (l2blockRemainingRows>=5) localRes[4] += ei_predux(dst[4]);
if (l2blockRemainingRows>=6) localRes[5] += ei_predux(dst[5]);
if (l2blockRemainingRows>=7) localRes[6] += ei_predux(dst[6]);
if (l2blockRemainingRows>=8) localRes[7] += ei_predux(dst[7]);
}
asm("#eigen end dynkernel");
}
}
}
}
}
if (PacketSize>1 && remainingSize)
{
if (lhsRowMajor)
{
for (int j=0; j<cols; ++j)
for (int i=0; i<rows; ++i)
{
Scalar tmp = lhs[i*lhsStride+size] * rhs[j*rhsStride+size];
for (int k=1; k<remainingSize; ++k)
tmp += lhs[i*lhsStride+size+k] * rhs[j*rhsStride+size+k];
res[i+j*resStride] += tmp;
}
}
else
{
for (int j=0; j<cols; ++j)
for (int i=0; i<rows; ++i)
{
Scalar tmp = lhs[i+size*lhsStride] * rhs[j*rhsStride+size];
for (int k=1; k<remainingSize; ++k)
tmp += lhs[i+(size+k)*lhsStride] * rhs[j*rhsStride+size+k];
res[i+j*resStride] += tmp;
}
}
}
}
#endif // EIGEN_CACHE_FRIENDLY_PRODUCT_H