Abandon blocking size lookup table approach. Not performing as well in real world as in microbenchmark.

5 files changed, 1 insertions, 221 deletions

diff --git a/Eigen/Core b/Eigen/Core
index 8a261d167..80d7c1a69 100644
--- a/Eigen/Core
+++ b/Eigen/Core
@@ -310,7 +310,6 @@ using std::ptrdiff_t;
   #include "src/Core/arch/NEON/PacketMath.h"
   #include "src/Core/arch/NEON/MathFunctions.h"
   #include "src/Core/arch/NEON/Complex.h"
-  #include "src/Core/arch/NEON/BlockingSizesLookupTables.h"
 #endif
 
 #if defined EIGEN_VECTORIZE_CUDA
@@ -384,7 +383,6 @@ using std::ptrdiff_t;
 #include "src/Core/Inverse.h"
 #include "src/Core/TriangularMatrix.h"
 #include "src/Core/SelfAdjointView.h"
-#include "src/Core/products/LookupBlockingSizesTable.h"
 #include "src/Core/products/GeneralBlockPanelKernel.h"
 #include "src/Core/products/Parallelizer.h"
 #include "src/Core/ProductEvaluators.h"
diff --git a/Eigen/src/Core/arch/NEON/BlockingSizesLookupTables.h b/Eigen/src/Core/arch/NEON/BlockingSizesLookupTables.h
deleted file mode 100644
index 5007c155d..000000000
--- a/Eigen/src/Core/arch/NEON/BlockingSizesLookupTables.h
+++ /dev/null
@@ -1,110 +0,0 @@
-// This file is part of Eigen, a lightweight C++ template library
-// for linear algebra.
-//
-// Copyright (C) 2015 Benoit Jacob <benoitjacob@google.com>
-//
-// This Source Code Form is subject to the terms of the Mozilla
-// Public License v. 2.0. If a copy of the MPL was not distributed
-// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-#ifndef EIGEN_NEON_BLOCKING_SIZES_LOOKUP_TABLES_H
-#define EIGEN_NEON_BLOCKING_SIZES_LOOKUP_TABLES_H
-
-namespace Eigen {
-namespace internal {
-
-/* The following lookup table was generated from measurements on a Nexus 5,
- * which has a Qualcomm Krait 400 CPU. This is very representative of current
- * 32bit (ARMv7) Android devices. On the other hand, I don't know how
- * representative that is outside of these conditions. Accordingly,
- * let's only use this lookup table on ARM 32bit on Android for now.
- *
- * Measurements were single-threaded, with Scalar=float, compiled with
- * -mfpu=neon-vfpv4, so the pmadd instruction used was VFMA.F32.
- *
- * The device was cooled, allowing it to run a the max clock speed throughout.
- * This may not be representative of real-world thermal conditions.
- *
- * The benchmark attempted to flush caches to test cold-cache performance.
- */
-#if EIGEN_ARCH_ARM && EIGEN_OS_ANDROID
-template<>
-struct BlockingSizesLookupTable<float, float> {
-  static const size_t BaseSize = 16;
-  static const size_t NumSizes = 8;
-  static const unsigned short* Data() {
-    static const unsigned short data[512] = {
-      0x444, 0x445, 0x446, 0x447, 0x448, 0x449, 0x447, 0x447,
-      0x454, 0x455, 0x456, 0x457, 0x458, 0x459, 0x45a, 0x456,
-      0x464, 0x465, 0x466, 0x467, 0x468, 0x469, 0x46a, 0x467,
-      0x474, 0x475, 0x476, 0x467, 0x478, 0x479, 0x476, 0x478,
-      0x474, 0x475, 0x476, 0x477, 0x478, 0x479, 0x476, 0x476,
-      0x474, 0x475, 0x476, 0x477, 0x478, 0x479, 0x496, 0x488,
-      0x474, 0x475, 0x476, 0x4a6, 0x496, 0x496, 0x495, 0x4a6,
-      0x474, 0x475, 0x466, 0x4a6, 0x497, 0x4a5, 0x496, 0x4a5,
-      0x544, 0x545, 0x546, 0x547, 0x548, 0x549, 0x54a, 0x54b,
-      0x554, 0x555, 0x556, 0x557, 0x558, 0x559, 0x55a, 0x55b,
-      0x564, 0x565, 0x566, 0x567, 0x568, 0x569, 0x56a, 0x56b,
-      0x564, 0x565, 0x566, 0x567, 0x568, 0x569, 0x56a, 0x576,
-      0x564, 0x565, 0x566, 0x567, 0x568, 0x569, 0x56a, 0x587,
-      0x564, 0x565, 0x566, 0x567, 0x596, 0x596, 0x596, 0x597,
-      0x574, 0x565, 0x566, 0x596, 0x596, 0x5a6, 0x5a6, 0x5a6,
-      0x564, 0x565, 0x5a6, 0x596, 0x5a6, 0x5a6, 0x5a6, 0x5a6,
-      0x644, 0x645, 0x646, 0x647, 0x648, 0x649, 0x64a, 0x64b,
-      0x644, 0x655, 0x656, 0x657, 0x658, 0x659, 0x65a, 0x65b,
-      0x664, 0x665, 0x666, 0x667, 0x668, 0x669, 0x65a, 0x667,
-      0x654, 0x665, 0x676, 0x677, 0x678, 0x679, 0x67a, 0x675,
-      0x684, 0x675, 0x686, 0x687, 0x688, 0x688, 0x687, 0x686,
-      0x664, 0x685, 0x666, 0x677, 0x697, 0x696, 0x697, 0x697,
-      0x664, 0x665, 0x696, 0x696, 0x685, 0x6a6, 0x696, 0x696,
-      0x664, 0x675, 0x686, 0x696, 0x6a6, 0x696, 0x696, 0x696,
-      0x744, 0x745, 0x746, 0x747, 0x748, 0x749, 0x74a, 0x747,
-      0x754, 0x755, 0x756, 0x757, 0x758, 0x759, 0x75a, 0x757,
-      0x764, 0x765, 0x756, 0x767, 0x768, 0x759, 0x75a, 0x766,
-      0x744, 0x755, 0x766, 0x777, 0x768, 0x759, 0x778, 0x777,
-      0x744, 0x745, 0x766, 0x777, 0x788, 0x786, 0x786, 0x788,
-      0x754, 0x755, 0x766, 0x787, 0x796, 0x796, 0x787, 0x796,
-      0x684, 0x695, 0x696, 0x6a6, 0x795, 0x786, 0x795, 0x796,
-      0x684, 0x695, 0x696, 0x795, 0x786, 0x796, 0x795, 0x796,
-      0x844, 0x845, 0x846, 0x847, 0x848, 0x849, 0x848, 0x848,
-      0x844, 0x855, 0x846, 0x847, 0x848, 0x849, 0x855, 0x857,
-      0x844, 0x845, 0x846, 0x857, 0x848, 0x859, 0x866, 0x865,
-      0x844, 0x855, 0x846, 0x847, 0x878, 0x859, 0x877, 0x877,
-      0x844, 0x855, 0x846, 0x867, 0x886, 0x887, 0x885, 0x886,
-      0x784, 0x785, 0x786, 0x877, 0x897, 0x885, 0x896, 0x896,
-      0x684, 0x695, 0x686, 0x886, 0x885, 0x885, 0x886, 0x896,
-      0x694, 0x6a5, 0x6a6, 0x885, 0x885, 0x886, 0x896, 0x896,
-      0x944, 0x945, 0x946, 0x947, 0x948, 0x847, 0x847, 0x848,
-      0x954, 0x855, 0x856, 0x947, 0x858, 0x857, 0x858, 0x858,
-      0x944, 0x945, 0x946, 0x867, 0x948, 0x866, 0x867, 0x867,
-      0x944, 0x975, 0x976, 0x877, 0x877, 0x877, 0x877, 0x877,
-      0x784, 0x785, 0x886, 0x887, 0x886, 0x887, 0x887, 0x887,
-      0x784, 0x785, 0x786, 0x796, 0x887, 0x897, 0x896, 0x896,
-      0x684, 0x695, 0x6a6, 0x886, 0x886, 0x896, 0x896, 0x896,
-      0x6a4, 0x6a5, 0x696, 0x896, 0x886, 0x896, 0x896, 0x896,
-      0xa44, 0xa45, 0xa46, 0xa47, 0x847, 0x848, 0x847, 0x848,
-      0xa44, 0xa45, 0x856, 0x857, 0x857, 0x857, 0x857, 0x857,
-      0xa44, 0xa65, 0x866, 0x867, 0x867, 0x867, 0x867, 0x867,
-      0x774, 0x875, 0x876, 0x877, 0x877, 0x877, 0x877, 0x877,
-      0x784, 0x785, 0x886, 0x887, 0x887, 0x887, 0x887, 0x887,
-      0x784, 0x785, 0x786, 0x787, 0x887, 0x896, 0x897, 0x897,
-      0x684, 0x6a5, 0x696, 0x886, 0x886, 0x896, 0x896, 0x896,
-      0x684, 0x6a5, 0x6a5, 0x886, 0x886, 0x896, 0x896, 0x896,
-      0xb44, 0x845, 0x846, 0x847, 0x847, 0x945, 0x846, 0x946,
-      0xb54, 0x855, 0x856, 0x857, 0x857, 0x856, 0x857, 0x856,
-      0x864, 0x865, 0x866, 0x867, 0x867, 0x866, 0x866, 0x867,
-      0x864, 0x875, 0x876, 0x877, 0x877, 0x877, 0x877, 0x877,
-      0x784, 0x885, 0x886, 0x787, 0x887, 0x887, 0x887, 0x887,
-      0x784, 0x785, 0x786, 0x796, 0x886, 0x897, 0x897, 0x897,
-      0x684, 0x695, 0x696, 0x886, 0x896, 0x896, 0x896, 0x896,
-      0x684, 0x685, 0x696, 0xb57, 0x896, 0x896, 0x896, 0x896
-    };
-    return data;
-  }
-};
-#endif
-
-}
-}
-
-#endif // EIGEN_NEON_BLOCKING_SIZES_LOOKUP_TABLES_H
diff --git a/Eigen/src/Core/products/GeneralBlockPanelKernel.h b/Eigen/src/Core/products/GeneralBlockPanelKernel.h
index 320f96a39..1d62ccd93 100644
--- a/Eigen/src/Core/products/GeneralBlockPanelKernel.h
+++ b/Eigen/src/Core/products/GeneralBlockPanelKernel.h
@@ -291,7 +291,6 @@ inline bool useSpecificBlockingSizes(Index& k, Index& m, Index& n)
   *
   * The blocking size parameters may be evaluated:
   *   - either by a heuristic based on cache sizes;
-  *   - or using a precomputed lookup table;
   *   - or using fixed prescribed values (for testing purposes).
   *
   * \sa setCpuCacheSizes */
@@ -300,9 +299,7 @@ template<typename LhsScalar, typename RhsScalar, int KcFactor>
 void computeProductBlockingSizes(Index& k, Index& m, Index& n, Index num_threads = 1)
 {
   if (!useSpecificBlockingSizes(k, m, n)) {
-    if (!lookupBlockingSizesFromTable<LhsScalar, RhsScalar>(k, m, n, num_threads)) {
-      evaluateProductBlockingSizesHeuristic<LhsScalar, RhsScalar, KcFactor>(k, m, n, num_threads);
-    }
+    evaluateProductBlockingSizesHeuristic<LhsScalar, RhsScalar, KcFactor>(k, m, n, num_threads);
   }
 
   typedef gebp_traits<LhsScalar,RhsScalar> Traits;
diff --git a/Eigen/src/Core/products/LookupBlockingSizesTable.h b/Eigen/src/Core/products/LookupBlockingSizesTable.h
deleted file mode 100644
index 39a53c8f1..000000000
--- a/Eigen/src/Core/products/LookupBlockingSizesTable.h
+++ /dev/null
@@ -1,97 +0,0 @@
-// This file is part of Eigen, a lightweight C++ template library
-// for linear algebra.
-//
-// Copyright (C) 2015 Benoit Jacob <benoitjacob@google.com>
-//
-// This Source Code Form is subject to the terms of the Mozilla
-// Public License v. 2.0. If a copy of the MPL was not distributed
-// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-#ifndef EIGEN_LOOKUP_BLOCKING_SIZES_TABLE_H
-#define EIGEN_LOOKUP_BLOCKING_SIZES_TABLE_H
-
-namespace Eigen {
-
-namespace internal {
-
-template <typename LhsScalar,
-          typename RhsScalar,
-          bool HasLookupTable = BlockingSizesLookupTable<LhsScalar, RhsScalar>::NumSizes != 0 >
-struct LookupBlockingSizesFromTableImpl
-{
-  static bool run(Index&, Index&, Index&, Index)
-  {
-    return false;
-  }
-};
-
-inline size_t floor_log2_helper(unsigned short& x, size_t offset)
-{
-  unsigned short y = x >> offset;
-  if (y) {
-    x = y;
-    return offset;
-  } else {
-    return 0;
-  }
-}
-
-inline size_t floor_log2(unsigned short x)
-{
-  return floor_log2_helper(x, 8)
-       + floor_log2_helper(x, 4)
-       + floor_log2_helper(x, 2)
-       + floor_log2_helper(x, 1);
-}
-
-inline size_t ceil_log2(unsigned short x)
-{
-  return x > 1 ? floor_log2(x - 1) + 1 : 0;
-}
-
-template <typename LhsScalar,
-          typename RhsScalar>
-struct LookupBlockingSizesFromTableImpl<LhsScalar, RhsScalar, true>
-{
-  static bool run(Index& k, Index& m, Index& n, Index)
-  {
-    using std::min;
-    using std::max;
-    typedef BlockingSizesLookupTable<LhsScalar, RhsScalar> Table;
-    const unsigned short minsize = Table::BaseSize;
-    const unsigned short maxsize = minsize << (Table::NumSizes - 1);
-    const unsigned short k_clamped = max<unsigned short>(minsize, min<Index>(k, maxsize));
-    const unsigned short m_clamped = max<unsigned short>(minsize, min<Index>(m, maxsize));
-    const unsigned short n_clamped = max<unsigned short>(minsize, min<Index>(n, maxsize));
-    const size_t k_index = ceil_log2(k_clamped / minsize);
-    const size_t m_index = ceil_log2(m_clamped / minsize);
-    const size_t n_index = ceil_log2(n_clamped / minsize);
-    const size_t index = n_index + Table::NumSizes * (m_index + Table::NumSizes * k_index);
-    const unsigned short table_entry = Table::Data()[index];
-    k = min<Index>(k, 1 << ((table_entry & 0xf00) >> 8));
-    m = min<Index>(m, 1 << ((table_entry & 0x0f0) >> 4));
-    n = min<Index>(n, 1 << ((table_entry & 0x00f) >> 0));
-    return true;
-  }
-};
-
-template <typename LhsScalar,
-          typename RhsScalar>
-bool lookupBlockingSizesFromTable(Index& k, Index& m, Index& n, Index num_threads)
-{
-  if (num_threads > 1) {
-    // We don't currently have lookup tables recorded for multithread performance,
-    // and we have confirmed experimentally that our single-thread-recorded LUTs are
-    // poor for multithread performance, and our LUTs don't currently contain
-    // any annotation about multithread status (FIXME - we need that).
-    // So for now, we just early-return here.
-    return false;
-  }
-  return LookupBlockingSizesFromTableImpl<LhsScalar, RhsScalar>::run(k, m, n, num_threads);
-}
-
-}
-
-}
-
-#endif // EIGEN_LOOKUP_BLOCKING_SIZES_TABLE_H
diff --git a/Eigen/src/Core/util/ForwardDeclarations.h b/Eigen/src/Core/util/ForwardDeclarations.h
index 503d5acdf..0d24beb5a 100644
--- a/Eigen/src/Core/util/ForwardDeclarations.h
+++ b/Eigen/src/Core/util/ForwardDeclarations.h
@@ -288,14 +288,6 @@ struct stem_function
   typedef std::complex<typename NumTraits<Scalar>::Real> ComplexScalar;
   typedef ComplexScalar type(ComplexScalar, int);
 };
-
-template <typename LhsScalar,
-          typename RhsScalar>
-struct BlockingSizesLookupTable
-{
-  static const size_t NumSizes = 0;
-};
-
 }
 
 } // end namespace Eigen