From 3589a9c115a892ea3ca5dac74d71a1526764cb38 Mon Sep 17 00:00:00 2001
From: Benoit Jacob <benoitjacob@google.com>
Date: Sun, 15 Mar 2015 18:12:18 -0400
Subject: [PATCH] actual_panel_rows computation should always be resilient to
 parameters not consistent with the known L1 cache size, see comment

---
 Eigen/src/Core/products/GeneralBlockPanelKernel.h | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/Eigen/src/Core/products/GeneralBlockPanelKernel.h b/Eigen/src/Core/products/GeneralBlockPanelKernel.h
index 617439ff6..6aadfea83 100644
--- a/Eigen/src/Core/products/GeneralBlockPanelKernel.h
+++ b/Eigen/src/Core/products/GeneralBlockPanelKernel.h
@@ -1017,11 +1017,10 @@ void gebp_kernel<LhsScalar,RhsScalar,Index,DataMapper,mr,nr,ConjugateLhs,Conjuga
       // However, if depth is too small, we can extend the number of rows of these horizontal panels.
       // This actual number of rows is computed as follow:
       const Index l1 = defaultL1CacheSize; // in Bytes, TODO, l1 should be passed to this function.
-#ifdef EIGEN_TEST_SPECIFIC_BLOCKING_SIZES
+      // The max(1, ...) here is needed because we may be using blocking params larger than what our known l1 cache size
+      // suggests we should be using: either because our known l1 cache size is inaccurate (e.g. on Android, we can only guess),
+      // or because we are testing specific blocking sizes.
       const Index actual_panel_rows = (3*LhsProgress) * std::max<Index>(1,( (l1 - sizeof(ResScalar)*mr*nr - depth*nr*sizeof(RhsScalar)) / (depth * sizeof(LhsScalar) * 3*LhsProgress) ));
-#else
-      const Index actual_panel_rows = (3*LhsProgress) * ( (l1 - sizeof(ResScalar)*mr*nr - depth*nr*sizeof(RhsScalar)) / (depth * sizeof(LhsScalar) * 3*LhsProgress) );
-#endif
       for(Index i1=0; i1<peeled_mc3; i1+=actual_panel_rows)
       {
         const Index actual_panel_end = (std::min)(i1+actual_panel_rows, peeled_mc3);