From 79b4e6acaf9f81155f4cdda9eb4bb6fe12aef5d7 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Tue, 31 Mar 2015 23:35:12 +0200
Subject: [PATCH] Fix bug #987: wrong alignement guess in diagonal product.

---
 Eigen/src/Core/ProductEvaluators.h |  3 +--
 test/diagonalmatrices.cpp          | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/Eigen/src/Core/ProductEvaluators.h b/Eigen/src/Core/ProductEvaluators.h
index d84e7776b..7960c274b 100644
--- a/Eigen/src/Core/ProductEvaluators.h
+++ b/Eigen/src/Core/ProductEvaluators.h
@@ -678,8 +678,7 @@ public:
     //_Vectorizable = bool(int(MatrixFlags)&PacketAccessBit) && ((!_PacketOnDiag) || (_SameTypes && bool(int(DiagFlags)&PacketAccessBit))),
     _Vectorizable = bool(int(MatrixFlags)&PacketAccessBit) && _SameTypes && (_ScalarAccessOnDiag || (bool(int(DiagFlags)&PacketAccessBit))),
     _LinearAccessMask = (MatrixType::RowsAtCompileTime==1 || MatrixType::ColsAtCompileTime==1) ? LinearAccessBit : 0,
-    Flags = ((HereditaryBits|_LinearAccessMask) & (unsigned int)(MatrixFlags)) | (_Vectorizable ? PacketAccessBit : 0) | AlignedBit
-            //(int(MatrixFlags)&int(DiagFlags)&AlignedBit),
+    Flags = ((HereditaryBits|_LinearAccessMask|AlignedBit) & (unsigned int)(MatrixFlags)) | (_Vectorizable ? PacketAccessBit : 0)
   };
   
   diagonal_product_evaluator_base(const MatrixType &mat, const DiagonalType &diag)
diff --git a/test/diagonalmatrices.cpp b/test/diagonalmatrices.cpp
index 0227ba577..cd6dc8cf0 100644
--- a/test/diagonalmatrices.cpp
+++ b/test/diagonalmatrices.cpp
@@ -17,6 +17,7 @@ template<typename MatrixType> void diagonalmatrices(const MatrixType& m)
   typedef Matrix<Scalar, Rows, 1> VectorType;
   typedef Matrix<Scalar, 1, Cols> RowVectorType;
   typedef Matrix<Scalar, Rows, Rows> SquareMatrixType;
+  typedef Matrix<Scalar, Dynamic, Dynamic> DynMatrixType;
   typedef DiagonalMatrix<Scalar, Rows> LeftDiagonalMatrix;
   typedef DiagonalMatrix<Scalar, Cols> RightDiagonalMatrix;
   typedef Matrix<Scalar, Rows==Dynamic?Dynamic:2*Rows, Cols==Dynamic?Dynamic:2*Cols> BigMatrix;
@@ -64,6 +65,13 @@ template<typename MatrixType> void diagonalmatrices(const MatrixType& m)
   VERIFY_IS_APPROX( (((v1+v2).asDiagonal() * (m1+m2))(i,j))  , (v1+v2)(i) * (m1+m2)(i,j) );
   VERIFY_IS_APPROX( ((m1 * (rv1+rv2).asDiagonal())(i,j))  , (rv1+rv2)(j) * m1(i,j) );
   VERIFY_IS_APPROX( (((m1+m2) * (rv1+rv2).asDiagonal())(i,j))  , (rv1+rv2)(j) * (m1+m2)(i,j) );
+  
+  if(rows>1)
+  {
+    DynMatrixType tmp = m1.topRows(rows/2), res;
+    VERIFY_IS_APPROX( (res = m1.topRows(rows/2) * rv1.asDiagonal()), tmp * rv1.asDiagonal() );
+    VERIFY_IS_APPROX( (res = v1.head(rows/2).asDiagonal()*m1.topRows(rows/2)), v1.head(rows/2).asDiagonal()*tmp );
+  }
 
   BigMatrix big;
   big.setZero(2*rows, 2*cols);
@@ -93,6 +101,17 @@ template<typename MatrixType> void diagonalmatrices(const MatrixType& m)
   VERIFY_IS_APPROX( (sq_m1 = (s1*v1).asDiagonal()), (s1*v1).asDiagonal().toDenseMatrix() );
 }
 
+template<int>
+void bug987()
+{
+  Matrix3Xd points = Matrix3Xd::Random(3, 3);
+  Vector2d diag = Vector2d::Random();
+  Matrix2Xd tmp1 = points.topRows<2>(), res1, res2;
+  VERIFY_IS_APPROX( res1 = diag.asDiagonal() * points.topRows<2>(), res2 = diag.asDiagonal() * tmp1 );
+  Matrix2d tmp2 = points.topLeftCorner<2,2>();
+  VERIFY_IS_APPROX(( res1 = points.topLeftCorner<2,2>()*diag.asDiagonal()) , res2 = tmp2*diag.asDiagonal() );
+}
+
 void test_diagonalmatrices()
 {
   for(int i = 0; i < g_repeat; i++) {
@@ -106,4 +125,5 @@ void test_diagonalmatrices()
     CALL_SUBTEST_8( diagonalmatrices(Matrix<double,Dynamic,Dynamic,RowMajor>(internal::random<int>(1,EIGEN_TEST_MAX_SIZE), internal::random<int>(1,EIGEN_TEST_MAX_SIZE))) );
     CALL_SUBTEST_9( diagonalmatrices(MatrixXf(internal::random<int>(1,EIGEN_TEST_MAX_SIZE), internal::random<int>(1,EIGEN_TEST_MAX_SIZE))) );
   }
+  CALL_SUBTEST_10( bug987<0>() );
 }