diff options
author | Rasmus Munk Larsen <rmlarsen@google.com> | 2020-04-27 18:55:15 -0700 |
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committer | Rasmus Munk Larsen <rmlarsen@google.com> | 2020-04-28 16:08:16 +0000 |
commit | b47c7779937c1984b7cd2f1d2f8df33d67c396f7 (patch) | |
tree | 676fe9f9be5faf255b282dde431295b1894f6813 /Eigen/src/Core/Transpose.h | |
parent | 29f0917a43bc4aefb987b180ad6cf19626fb0c23 (diff) |
Block transposeInPlace() when the matrix is real and square. This yields a large speedup because we transpose in registers (or L1 if we spill), instead of one packet at a time, which in the worst case makes the code write to the same cache line PacketSize times instead of once.
rmlarsen@rmlarsen4:.../eigen_bench/google3$ benchy --benchmarks=.*TransposeInPlace.*float.* --reference=srcfs experimental/users/rmlarsen/bench:matmul_bench
10 / 10 [====================================================================================================================================================================================================================] 100.00% 2m50s
(Generated by http://go/benchy. Settings: --runs 5 --benchtime 1s --reference "srcfs" --benchmarks ".*TransposeInPlace.*float.*" experimental/users/rmlarsen/bench:matmul_bench)
name old time/op new time/op delta
BM_TransposeInPlace<float>/4 9.84ns ± 0% 6.51ns ± 0% -33.80% (p=0.008 n=5+5)
BM_TransposeInPlace<float>/8 23.6ns ± 1% 17.6ns ± 0% -25.26% (p=0.016 n=5+4)
BM_TransposeInPlace<float>/16 78.8ns ± 0% 60.3ns ± 0% -23.50% (p=0.029 n=4+4)
BM_TransposeInPlace<float>/32 302ns ± 0% 229ns ± 0% -24.40% (p=0.008 n=5+5)
BM_TransposeInPlace<float>/59 1.03µs ± 0% 0.84µs ± 1% -17.87% (p=0.016 n=5+4)
BM_TransposeInPlace<float>/64 1.20µs ± 0% 0.89µs ± 1% -25.81% (p=0.008 n=5+5)
BM_TransposeInPlace<float>/128 8.96µs ± 0% 3.82µs ± 2% -57.33% (p=0.008 n=5+5)
BM_TransposeInPlace<float>/256 152µs ± 3% 17µs ± 2% -89.06% (p=0.008 n=5+5)
BM_TransposeInPlace<float>/512 837µs ± 1% 208µs ± 0% -75.15% (p=0.008 n=5+5)
BM_TransposeInPlace<float>/1k 4.28ms ± 2% 1.08ms ± 2% -74.72% (p=0.008 n=5+5)
Diffstat (limited to 'Eigen/src/Core/Transpose.h')
-rw-r--r-- | Eigen/src/Core/Transpose.h | 58 |
1 files changed, 53 insertions, 5 deletions
diff --git a/Eigen/src/Core/Transpose.h b/Eigen/src/Core/Transpose.h index 6dafe1b1e..a3f402cf3 100644 --- a/Eigen/src/Core/Transpose.h +++ b/Eigen/src/Core/Transpose.h @@ -243,7 +243,6 @@ struct inplace_transpose_selector<MatrixType,true,false> { // square matrix } }; -// TODO: vectorized path is currently limited to LargestPacketSize x LargestPacketSize cases only. template<typename MatrixType> struct inplace_transpose_selector<MatrixType,true,true> { // PacketSize x PacketSize static void run(MatrixType& m) { @@ -260,16 +259,65 @@ struct inplace_transpose_selector<MatrixType,true,true> { // PacketSize x Packet } }; + +template <typename MatrixType, Index Alignment> +void BlockedInPlaceTranspose(MatrixType& m) { + typedef typename MatrixType::Scalar Scalar; + typedef typename internal::packet_traits<typename MatrixType::Scalar>::type Packet; + const Index PacketSize = internal::packet_traits<Scalar>::size; + eigen_assert(m.rows() == m.cols()); + int row_start = 0; + for (; row_start + PacketSize <= m.rows(); row_start += PacketSize) { + for (int col_start = row_start; col_start + PacketSize <= m.cols(); col_start += PacketSize) { + PacketBlock<Packet> A; + if (row_start == col_start) { + for (Index i=0; i<PacketSize; ++i) + A.packet[i] = m.template packetByOuterInner<Alignment>(row_start + i,col_start); + internal::ptranspose(A); + for (Index i=0; i<PacketSize; ++i) + m.template writePacket<Alignment>(m.rowIndexByOuterInner(row_start + i, col_start), m.colIndexByOuterInner(row_start + i,col_start), A.packet[i]); + } else { + PacketBlock<Packet> B; + for (Index i=0; i<PacketSize; ++i) { + A.packet[i] = m.template packetByOuterInner<Alignment>(row_start + i,col_start); + B.packet[i] = m.template packetByOuterInner<Alignment>(col_start + i, row_start); + } + internal::ptranspose(A); + internal::ptranspose(B); + for (Index i=0; i<PacketSize; ++i) { + m.template writePacket<Alignment>(m.rowIndexByOuterInner(row_start + i, col_start), m.colIndexByOuterInner(row_start + i,col_start), A.packet[i]); + m.template writePacket<Alignment>(m.rowIndexByOuterInner(col_start + i, row_start), m.colIndexByOuterInner(col_start + i,row_start), B.packet[i]); + } + } + } + } + for (Index row = row_start; row < m.rows(); ++row) { + m.matrix().row(row).swap(m.matrix().col(row)); + } +} + template<typename MatrixType,bool MatchPacketSize> -struct inplace_transpose_selector<MatrixType,false,MatchPacketSize> { // non square matrix +struct inplace_transpose_selector<MatrixType,false,MatchPacketSize> { // non square or dynamic matrix static void run(MatrixType& m) { - if (m.rows()==m.cols()) - m.matrix().template triangularView<StrictlyUpper>().swap(m.matrix().transpose().template triangularView<StrictlyUpper>()); - else + typedef typename MatrixType::Scalar Scalar; + if (m.rows() == m.cols()) { + const Index PacketSize = internal::packet_traits<Scalar>::size; + if (!NumTraits<Scalar>::IsComplex && m.rows() >= PacketSize) { + if ((m.rows() % PacketSize) == 0) + BlockedInPlaceTranspose<MatrixType,internal::evaluator<MatrixType>::Alignment>(m); + else + BlockedInPlaceTranspose<MatrixType,Unaligned>(m); + } + else { + m.matrix().template triangularView<StrictlyUpper>().swap(m.matrix().transpose().template triangularView<StrictlyUpper>()); + } + } else { m = m.transpose().eval(); + } } }; + } // end namespace internal /** This is the "in place" version of transpose(): it replaces \c *this by its own transpose. |