eigen/Eigen/src/Core/CacheFriendlyProduct.h
Gael Guennebaud 8302ce6cdc remove the special version of ei_pow(int,int) for gcc >= 4.3 that was stupid
because gcc convert it to a pow(double,double)
2009-07-16 09:10:34 +02:00

754 lines
29 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 <int L2MemorySize,typename Scalar>
struct ei_L2_block_traits {
enum {width = 8 * ei_meta_sqrt<L2MemorySize/(64*sizeof(Scalar))>::ret };
};
#ifndef EIGEN_EXTERN_INSTANTIATIONS
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* EIGEN_RESTRICT lhs;
const Scalar* EIGEN_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 = ei_L2_block_traits<EIGEN_TUNE_FOR_CPU_CACHE_SIZE,Scalar>::width
};
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;
const int l2BlockSizeAligned = (1 + std::max(l2BlockSize,l2BlockCols)/PacketSize)*PacketSize;
const bool needRhsCopy = (PacketSize>1) && ((rhsStride%PacketSize!=0) || (size_t(rhs)%16!=0));
Scalar* EIGEN_RESTRICT block = 0;
const int allocBlockSize = l2BlockRows*size;
block = ei_aligned_stack_new(Scalar, allocBlockSize);
Scalar* EIGEN_RESTRICT rhsCopy
= ei_aligned_stack_new(Scalar, l2BlockSizeAligned*l2BlockSizeAligned);
// 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
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" using something like:
// 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];
}
}
}
}
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);
// if not aligned, copy the rhs block
if (needRhsCopy)
for(int l1j=l2j; l1j<l2blockColEnd; l1j+=1)
{
ei_internal_assert(l2BlockSizeAligned*(l1j-l2j)+(l2blockSizeEnd-l2k) < l2BlockSizeAligned*l2BlockSizeAligned);
memcpy(rhsCopy+l2BlockSizeAligned*(l1j-l2j),&(rhs[l1j*rhsStride+l2k]),(l2blockSizeEnd-l2k)*sizeof(Scalar));
}
// for each bw x 1 result's block
for(int l1i=l2i; l1i<l2blockRowEndBW; l1i+=MaxBlockRows)
{
int offsetblock = l2k * (l2blockRowEnd-l2i) + (l1i-l2i)*(l2blockSizeEnd-l2k) - l2k*MaxBlockRows;
const Scalar* EIGEN_RESTRICT localB = &block[offsetblock];
for(int l1j=l2j; l1j<l2blockColEnd; l1j+=1)
{
const Scalar* EIGEN_RESTRICT rhsColumn;
if (needRhsCopy)
rhsColumn = &(rhsCopy[l2BlockSizeAligned*(l1j-l2j)-l2k]);
else
rhsColumn = &(rhs[l1j*rhsStride]);
PacketType dst[MaxBlockRows];
dst[3] = dst[2] = dst[1] = dst[0] = ei_pset1(Scalar(0.));
if (MaxBlockRows==8)
dst[7] = dst[6] = dst[5] = dst[4] = dst[0];
PacketType tmp;
for(int k=l2k; k<l2blockSizeEnd; k+=PacketSize)
{
tmp = ei_ploadu(&rhsColumn[k]);
PacketType A0, A1, A2, A3, A4, A5;
A0 = ei_pload(localB + k*MaxBlockRows);
A1 = ei_pload(localB + k*MaxBlockRows+1*PacketSize);
A2 = ei_pload(localB + k*MaxBlockRows+2*PacketSize);
A3 = ei_pload(localB + k*MaxBlockRows+3*PacketSize);
if (MaxBlockRows==8) A4 = ei_pload(localB + k*MaxBlockRows+4*PacketSize);
if (MaxBlockRows==8) A5 = ei_pload(localB + k*MaxBlockRows+5*PacketSize);
dst[0] = ei_pmadd(tmp, A0, dst[0]);
if (MaxBlockRows==8) A0 = ei_pload(localB + k*MaxBlockRows+6*PacketSize);
dst[1] = ei_pmadd(tmp, A1, dst[1]);
if (MaxBlockRows==8) A1 = ei_pload(localB + k*MaxBlockRows+7*PacketSize);
dst[2] = ei_pmadd(tmp, A2, dst[2]);
dst[3] = ei_pmadd(tmp, A3, dst[3]);
if (MaxBlockRows==8)
{
dst[4] = ei_pmadd(tmp, A4, dst[4]);
dst[5] = ei_pmadd(tmp, A5, dst[5]);
dst[6] = ei_pmadd(tmp, A0, dst[6]);
dst[7] = ei_pmadd(tmp, A1, dst[7]);
}
}
Scalar* EIGEN_RESTRICT localRes = &(res[l1i + l1j*resStride]);
if (PacketSize>1 && resIsAligned)
{
// the result is aligned: let's do packet reduction
ei_pstore(&(localRes[0]), ei_padd(ei_pload(&(localRes[0])), ei_preduxp(&dst[0])));
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
{
// not aligned => per coeff packet reduction
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]);
}
}
}
}
if (l2blockRemainingRows>0)
{
int offsetblock = l2k * (l2blockRowEnd-l2i) + (l2blockRowEndBW-l2i)*(l2blockSizeEnd-l2k) - l2k*l2blockRemainingRows;
const Scalar* localB = &block[offsetblock];
for(int l1j=l2j; l1j<l2blockColEnd; l1j+=1)
{
const Scalar* EIGEN_RESTRICT rhsColumn;
if (needRhsCopy)
rhsColumn = &(rhsCopy[l2BlockSizeAligned*(l1j-l2j)-l2k]);
else
rhsColumn = &(rhs[l1j*rhsStride]);
PacketType dst[MaxBlockRows];
dst[3] = dst[2] = dst[1] = dst[0] = ei_pset1(Scalar(0.));
if (MaxBlockRows==8)
dst[7] = dst[6] = dst[5] = dst[4] = 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==8)
{
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* EIGEN_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==8)
{
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]);
}
}
}
}
}
}
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];
// FIXME this loop get vectorized by the compiler !
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;
}
}
}
ei_aligned_stack_delete(Scalar, block, allocBlockSize);
ei_aligned_stack_delete(Scalar, rhsCopy, l2BlockSizeAligned*l2BlockSizeAligned);
}
#endif // EIGEN_EXTERN_INSTANTIATIONS
/* Optimized col-major matrix * vector product:
* This algorithm processes 4 columns at onces that allows to both reduce
* the number of load/stores of the result by a factor 4 and to reduce
* the instruction dependency. Moreover, we know that all bands have the
* same alignment pattern.
* TODO: since rhs gets evaluated only once, no need to evaluate it
*/
template<typename Scalar, typename RhsType>
static EIGEN_DONT_INLINE void ei_cache_friendly_product_colmajor_times_vector(
int size,
const Scalar* lhs, int lhsStride,
const RhsType& rhs,
Scalar* res)
{
#ifdef _EIGEN_ACCUMULATE_PACKETS
#error _EIGEN_ACCUMULATE_PACKETS has already been defined
#endif
#define _EIGEN_ACCUMULATE_PACKETS(A0,A13,A2) \
ei_pstore(&res[j], \
ei_padd(ei_pload(&res[j]), \
ei_padd( \
ei_padd(ei_pmul(ptmp0,EIGEN_CAT(ei_ploa , A0)(&lhs0[j])), \
ei_pmul(ptmp1,EIGEN_CAT(ei_ploa , A13)(&lhs1[j]))), \
ei_padd(ei_pmul(ptmp2,EIGEN_CAT(ei_ploa , A2)(&lhs2[j])), \
ei_pmul(ptmp3,EIGEN_CAT(ei_ploa , A13)(&lhs3[j]))) )))
typedef typename ei_packet_traits<Scalar>::type Packet;
const int PacketSize = sizeof(Packet)/sizeof(Scalar);
enum { AllAligned = 0, EvenAligned, FirstAligned, NoneAligned };
const int columnsAtOnce = 4;
const int peels = 2;
const int PacketAlignedMask = PacketSize-1;
const int PeelAlignedMask = PacketSize*peels-1;
// How many coeffs of the result do we have to skip to be aligned.
// Here we assume data are at least aligned on the base scalar type that is mandatory anyway.
const int alignedStart = ei_alignmentOffset(res,size);
const int alignedSize = PacketSize>1 ? alignedStart + ((size-alignedStart) & ~PacketAlignedMask) : 0;
const int peeledSize = peels>1 ? alignedStart + ((alignedSize-alignedStart) & ~PeelAlignedMask) : alignedStart;
const int alignmentStep = PacketSize>1 ? (PacketSize - lhsStride % PacketSize) & PacketAlignedMask : 0;
int alignmentPattern = alignmentStep==0 ? AllAligned
: alignmentStep==(PacketSize/2) ? EvenAligned
: FirstAligned;
// we cannot assume the first element is aligned because of sub-matrices
const int lhsAlignmentOffset = ei_alignmentOffset(lhs,size);
// find how many columns do we have to skip to be aligned with the result (if possible)
int skipColumns = 0;
if (PacketSize>1)
{
ei_internal_assert(size_t(lhs+lhsAlignmentOffset)%sizeof(Packet)==0 || size<PacketSize);
while (skipColumns<PacketSize &&
alignedStart != ((lhsAlignmentOffset + alignmentStep*skipColumns)%PacketSize))
++skipColumns;
if (skipColumns==PacketSize)
{
// nothing can be aligned, no need to skip any column
alignmentPattern = NoneAligned;
skipColumns = 0;
}
else
{
skipColumns = std::min(skipColumns,rhs.size());
// note that the skiped columns are processed later.
}
ei_internal_assert((alignmentPattern==NoneAligned) || (size_t(lhs+alignedStart+lhsStride*skipColumns)%sizeof(Packet))==0);
}
int offset1 = (FirstAligned && alignmentStep==1?3:1);
int offset3 = (FirstAligned && alignmentStep==1?1:3);
int columnBound = ((rhs.size()-skipColumns)/columnsAtOnce)*columnsAtOnce + skipColumns;
for (int i=skipColumns; i<columnBound; i+=columnsAtOnce)
{
Packet ptmp0 = ei_pset1(rhs[i]), ptmp1 = ei_pset1(rhs[i+offset1]),
ptmp2 = ei_pset1(rhs[i+2]), ptmp3 = ei_pset1(rhs[i+offset3]);
// this helps a lot generating better binary code
const Scalar *lhs0 = lhs + i*lhsStride, *lhs1 = lhs + (i+offset1)*lhsStride,
*lhs2 = lhs + (i+2)*lhsStride, *lhs3 = lhs + (i+offset3)*lhsStride;
if (PacketSize>1)
{
/* explicit vectorization */
// process initial unaligned coeffs
for (int j=0; j<alignedStart; ++j)
res[j] += ei_pfirst(ptmp0)*lhs0[j] + ei_pfirst(ptmp1)*lhs1[j] + ei_pfirst(ptmp2)*lhs2[j] + ei_pfirst(ptmp3)*lhs3[j];
if (alignedSize>alignedStart)
{
switch(alignmentPattern)
{
case AllAligned:
for (int j = alignedStart; j<alignedSize; j+=PacketSize)
_EIGEN_ACCUMULATE_PACKETS(d,d,d);
break;
case EvenAligned:
for (int j = alignedStart; j<alignedSize; j+=PacketSize)
_EIGEN_ACCUMULATE_PACKETS(d,du,d);
break;
case FirstAligned:
if(peels>1)
{
Packet A00, A01, A02, A03, A10, A11, A12, A13;
A01 = ei_pload(&lhs1[alignedStart-1]);
A02 = ei_pload(&lhs2[alignedStart-2]);
A03 = ei_pload(&lhs3[alignedStart-3]);
for (int j = alignedStart; j<peeledSize; j+=peels*PacketSize)
{
A11 = ei_pload(&lhs1[j-1+PacketSize]); ei_palign<1>(A01,A11);
A12 = ei_pload(&lhs2[j-2+PacketSize]); ei_palign<2>(A02,A12);
A13 = ei_pload(&lhs3[j-3+PacketSize]); ei_palign<3>(A03,A13);
A00 = ei_pload (&lhs0[j]);
A10 = ei_pload (&lhs0[j+PacketSize]);
A00 = ei_pmadd(ptmp0, A00, ei_pload(&res[j]));
A10 = ei_pmadd(ptmp0, A10, ei_pload(&res[j+PacketSize]));
A00 = ei_pmadd(ptmp1, A01, A00);
A01 = ei_pload(&lhs1[j-1+2*PacketSize]); ei_palign<1>(A11,A01);
A00 = ei_pmadd(ptmp2, A02, A00);
A02 = ei_pload(&lhs2[j-2+2*PacketSize]); ei_palign<2>(A12,A02);
A00 = ei_pmadd(ptmp3, A03, A00);
ei_pstore(&res[j],A00);
A03 = ei_pload(&lhs3[j-3+2*PacketSize]); ei_palign<3>(A13,A03);
A10 = ei_pmadd(ptmp1, A11, A10);
A10 = ei_pmadd(ptmp2, A12, A10);
A10 = ei_pmadd(ptmp3, A13, A10);
ei_pstore(&res[j+PacketSize],A10);
}
}
for (int j = peeledSize; j<alignedSize; j+=PacketSize)
_EIGEN_ACCUMULATE_PACKETS(d,du,du);
break;
default:
for (int j = alignedStart; j<alignedSize; j+=PacketSize)
_EIGEN_ACCUMULATE_PACKETS(du,du,du);
break;
}
}
} // end explicit vectorization
/* process remaining coeffs (or all if there is no explicit vectorization) */
for (int j=alignedSize; j<size; ++j)
res[j] += ei_pfirst(ptmp0)*lhs0[j] + ei_pfirst(ptmp1)*lhs1[j] + ei_pfirst(ptmp2)*lhs2[j] + ei_pfirst(ptmp3)*lhs3[j];
}
// process remaining first and last columns (at most columnsAtOnce-1)
int end = rhs.size();
int start = columnBound;
do
{
for (int i=start; i<end; ++i)
{
Packet ptmp0 = ei_pset1(rhs[i]);
const Scalar* lhs0 = lhs + i*lhsStride;
if (PacketSize>1)
{
/* explicit vectorization */
// process first unaligned result's coeffs
for (int j=0; j<alignedStart; ++j)
res[j] += ei_pfirst(ptmp0) * lhs0[j];
// process aligned result's coeffs
if ((size_t(lhs0+alignedStart)%sizeof(Packet))==0)
for (int j = alignedStart;j<alignedSize;j+=PacketSize)
ei_pstore(&res[j], ei_pmadd(ptmp0,ei_pload(&lhs0[j]),ei_pload(&res[j])));
else
for (int j = alignedStart;j<alignedSize;j+=PacketSize)
ei_pstore(&res[j], ei_pmadd(ptmp0,ei_ploadu(&lhs0[j]),ei_pload(&res[j])));
}
// process remaining scalars (or all if no explicit vectorization)
for (int j=alignedSize; j<size; ++j)
res[j] += ei_pfirst(ptmp0) * lhs0[j];
}
if (skipColumns)
{
start = 0;
end = skipColumns;
skipColumns = 0;
}
else
break;
} while(PacketSize>1);
#undef _EIGEN_ACCUMULATE_PACKETS
}
// TODO add peeling to mask unaligned load/stores
template<typename Scalar, typename ResType>
static EIGEN_DONT_INLINE void ei_cache_friendly_product_rowmajor_times_vector(
const Scalar* lhs, int lhsStride,
const Scalar* rhs, int rhsSize,
ResType& res)
{
#ifdef _EIGEN_ACCUMULATE_PACKETS
#error _EIGEN_ACCUMULATE_PACKETS has already been defined
#endif
#define _EIGEN_ACCUMULATE_PACKETS(A0,A13,A2) {\
Packet b = ei_pload(&rhs[j]); \
ptmp0 = ei_pmadd(b, EIGEN_CAT(ei_ploa,A0) (&lhs0[j]), ptmp0); \
ptmp1 = ei_pmadd(b, EIGEN_CAT(ei_ploa,A13)(&lhs1[j]), ptmp1); \
ptmp2 = ei_pmadd(b, EIGEN_CAT(ei_ploa,A2) (&lhs2[j]), ptmp2); \
ptmp3 = ei_pmadd(b, EIGEN_CAT(ei_ploa,A13)(&lhs3[j]), ptmp3); }
typedef typename ei_packet_traits<Scalar>::type Packet;
const int PacketSize = sizeof(Packet)/sizeof(Scalar);
enum { AllAligned=0, EvenAligned=1, FirstAligned=2, NoneAligned=3 };
const int rowsAtOnce = 4;
const int peels = 2;
const int PacketAlignedMask = PacketSize-1;
const int PeelAlignedMask = PacketSize*peels-1;
const int size = rhsSize;
// How many coeffs of the result do we have to skip to be aligned.
// Here we assume data are at least aligned on the base scalar type that is mandatory anyway.
const int alignedStart = ei_alignmentOffset(rhs, size);
const int alignedSize = PacketSize>1 ? alignedStart + ((size-alignedStart) & ~PacketAlignedMask) : 0;
const int peeledSize = peels>1 ? alignedStart + ((alignedSize-alignedStart) & ~PeelAlignedMask) : alignedStart;
const int alignmentStep = PacketSize>1 ? (PacketSize - lhsStride % PacketSize) & PacketAlignedMask : 0;
int alignmentPattern = alignmentStep==0 ? AllAligned
: alignmentStep==(PacketSize/2) ? EvenAligned
: FirstAligned;
// we cannot assume the first element is aligned because of sub-matrices
const int lhsAlignmentOffset = ei_alignmentOffset(lhs,size);
// find how many rows do we have to skip to be aligned with rhs (if possible)
int skipRows = 0;
if (PacketSize>1)
{
ei_internal_assert(size_t(lhs+lhsAlignmentOffset)%sizeof(Packet)==0 || size<PacketSize);
while (skipRows<PacketSize &&
alignedStart != ((lhsAlignmentOffset + alignmentStep*skipRows)%PacketSize))
++skipRows;
if (skipRows==PacketSize)
{
// nothing can be aligned, no need to skip any column
alignmentPattern = NoneAligned;
skipRows = 0;
}
else
{
skipRows = std::min(skipRows,res.size());
// note that the skiped columns are processed later.
}
ei_internal_assert((alignmentPattern==NoneAligned) || PacketSize==1
|| (size_t(lhs+alignedStart+lhsStride*skipRows)%sizeof(Packet))==0);
}
int offset1 = (FirstAligned && alignmentStep==1?3:1);
int offset3 = (FirstAligned && alignmentStep==1?1:3);
int rowBound = ((res.size()-skipRows)/rowsAtOnce)*rowsAtOnce + skipRows;
for (int i=skipRows; i<rowBound; i+=rowsAtOnce)
{
Scalar tmp0 = Scalar(0), tmp1 = Scalar(0), tmp2 = Scalar(0), tmp3 = Scalar(0);
// this helps the compiler generating good binary code
const Scalar *lhs0 = lhs + i*lhsStride, *lhs1 = lhs + (i+offset1)*lhsStride,
*lhs2 = lhs + (i+2)*lhsStride, *lhs3 = lhs + (i+offset3)*lhsStride;
if (PacketSize>1)
{
/* explicit vectorization */
Packet ptmp0 = ei_pset1(Scalar(0)), ptmp1 = ei_pset1(Scalar(0)), ptmp2 = ei_pset1(Scalar(0)), ptmp3 = ei_pset1(Scalar(0));
// process initial unaligned coeffs
// FIXME this loop get vectorized by the compiler !
for (int j=0; j<alignedStart; ++j)
{
Scalar b = rhs[j];
tmp0 += b*lhs0[j]; tmp1 += b*lhs1[j]; tmp2 += b*lhs2[j]; tmp3 += b*lhs3[j];
}
if (alignedSize>alignedStart)
{
switch(alignmentPattern)
{
case AllAligned:
for (int j = alignedStart; j<alignedSize; j+=PacketSize)
_EIGEN_ACCUMULATE_PACKETS(d,d,d);
break;
case EvenAligned:
for (int j = alignedStart; j<alignedSize; j+=PacketSize)
_EIGEN_ACCUMULATE_PACKETS(d,du,d);
break;
case FirstAligned:
if (peels>1)
{
/* Here we proccess 4 rows with with two peeled iterations to hide
* tghe overhead of unaligned loads. Moreover unaligned loads are handled
* using special shift/move operations between the two aligned packets
* overlaping the desired unaligned packet. This is *much* more efficient
* than basic unaligned loads.
*/
Packet A01, A02, A03, b, A11, A12, A13;
A01 = ei_pload(&lhs1[alignedStart-1]);
A02 = ei_pload(&lhs2[alignedStart-2]);
A03 = ei_pload(&lhs3[alignedStart-3]);
for (int j = alignedStart; j<peeledSize; j+=peels*PacketSize)
{
b = ei_pload(&rhs[j]);
A11 = ei_pload(&lhs1[j-1+PacketSize]); ei_palign<1>(A01,A11);
A12 = ei_pload(&lhs2[j-2+PacketSize]); ei_palign<2>(A02,A12);
A13 = ei_pload(&lhs3[j-3+PacketSize]); ei_palign<3>(A03,A13);
ptmp0 = ei_pmadd(b, ei_pload (&lhs0[j]), ptmp0);
ptmp1 = ei_pmadd(b, A01, ptmp1);
A01 = ei_pload(&lhs1[j-1+2*PacketSize]); ei_palign<1>(A11,A01);
ptmp2 = ei_pmadd(b, A02, ptmp2);
A02 = ei_pload(&lhs2[j-2+2*PacketSize]); ei_palign<2>(A12,A02);
ptmp3 = ei_pmadd(b, A03, ptmp3);
A03 = ei_pload(&lhs3[j-3+2*PacketSize]); ei_palign<3>(A13,A03);
b = ei_pload(&rhs[j+PacketSize]);
ptmp0 = ei_pmadd(b, ei_pload (&lhs0[j+PacketSize]), ptmp0);
ptmp1 = ei_pmadd(b, A11, ptmp1);
ptmp2 = ei_pmadd(b, A12, ptmp2);
ptmp3 = ei_pmadd(b, A13, ptmp3);
}
}
for (int j = peeledSize; j<alignedSize; j+=PacketSize)
_EIGEN_ACCUMULATE_PACKETS(d,du,du);
break;
default:
for (int j = alignedStart; j<alignedSize; j+=PacketSize)
_EIGEN_ACCUMULATE_PACKETS(du,du,du);
break;
}
tmp0 += ei_predux(ptmp0);
tmp1 += ei_predux(ptmp1);
tmp2 += ei_predux(ptmp2);
tmp3 += ei_predux(ptmp3);
}
} // end explicit vectorization
// process remaining coeffs (or all if no explicit vectorization)
// FIXME this loop get vectorized by the compiler !
for (int j=alignedSize; j<size; ++j)
{
Scalar b = rhs[j];
tmp0 += b*lhs0[j]; tmp1 += b*lhs1[j]; tmp2 += b*lhs2[j]; tmp3 += b*lhs3[j];
}
res[i] += tmp0; res[i+offset1] += tmp1; res[i+2] += tmp2; res[i+offset3] += tmp3;
}
// process remaining first and last rows (at most columnsAtOnce-1)
int end = res.size();
int start = rowBound;
do
{
for (int i=start; i<end; ++i)
{
Scalar tmp0 = Scalar(0);
Packet ptmp0 = ei_pset1(tmp0);
const Scalar* lhs0 = lhs + i*lhsStride;
// process first unaligned result's coeffs
// FIXME this loop get vectorized by the compiler !
for (int j=0; j<alignedStart; ++j)
tmp0 += rhs[j] * lhs0[j];
if (alignedSize>alignedStart)
{
// process aligned rhs coeffs
if ((size_t(lhs0+alignedStart)%sizeof(Packet))==0)
for (int j = alignedStart;j<alignedSize;j+=PacketSize)
ptmp0 = ei_pmadd(ei_pload(&rhs[j]), ei_pload(&lhs0[j]), ptmp0);
else
for (int j = alignedStart;j<alignedSize;j+=PacketSize)
ptmp0 = ei_pmadd(ei_pload(&rhs[j]), ei_ploadu(&lhs0[j]), ptmp0);
tmp0 += ei_predux(ptmp0);
}
// process remaining scalars
// FIXME this loop get vectorized by the compiler !
for (int j=alignedSize; j<size; ++j)
tmp0 += rhs[j] * lhs0[j];
res[i] += tmp0;
}
if (skipRows)
{
start = 0;
end = skipRows;
skipRows = 0;
}
else
break;
} while(PacketSize>1);
#undef _EIGEN_ACCUMULATE_PACKETS
}
#endif // EIGEN_CACHE_FRIENDLY_PRODUCT_H