From 515ecddb97da7f239747c8d547bfb9ed5d63ae0f Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Fri, 9 Oct 2015 14:29:46 +0200
Subject: [PATCH] Add unit test for nested_eval

---
 test/nesting_ops.cpp | 84 +++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 79 insertions(+), 5 deletions(-)

diff --git a/test/nesting_ops.cpp b/test/nesting_ops.cpp
index 6e772c70f..15b231d2e 100644
--- a/test/nesting_ops.cpp
+++ b/test/nesting_ops.cpp
@@ -2,14 +2,35 @@
 // for linear algebra.
 //
 // Copyright (C) 2010 Hauke Heibel <hauke.heibel@gmail.com>
+// Copyright (C) 2015 Gael Guennebaud <gael.guennebaud@inria.fr>
 //
 // 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/.
 
+#define TEST_ENABLE_TEMPORARY_TRACKING
+
 #include "main.h"
 
-template <typename MatrixType> void run_nesting_ops(const MatrixType& _m)
+template <int N, typename XprType>
+void use_n_times(const XprType &xpr)
+{
+  typename internal::nested_eval<XprType,N>::type mat(xpr);
+  typename XprType::PlainObject res(mat.rows(), mat.cols());
+  nb_temporaries--; // remove res
+  res.setZero();
+  for(int i=0; i<N; ++i)
+    res += mat;
+}
+
+template <int N, typename ReferenceType, typename XprType>
+bool verify_eval_type(const XprType &, const ReferenceType&)
+{
+  typedef typename internal::nested_eval<XprType,N>::type EvalType;
+  return internal::is_same<typename internal::remove_all<EvalType>::type, typename internal::remove_all<ReferenceType>::type>::value;
+}
+
+template <typename MatrixType> void run_nesting_ops_1(const MatrixType& _m)
 {
   typename internal::nested_eval<MatrixType,2>::type m(_m);
 
@@ -24,10 +45,63 @@ template <typename MatrixType> void run_nesting_ops(const MatrixType& _m)
   VERIFY_IS_APPROX( (m.transpose() * m).array().abs().sum(), (m.transpose() * m).array().abs().sum() );
 }
 
+template <typename MatrixType> void run_nesting_ops_2(const MatrixType& _m)
+{
+  Index rows = _m.rows();
+  Index cols = _m.cols();
+  MatrixType m1 = MatrixType::Random(rows,cols);
+
+  if((MatrixType::SizeAtCompileTime==Dynamic))
+  {
+
+    VERIFY_EVALUATION_COUNT( use_n_times<10>(m1), 0 );
+    if(!NumTraits<typename MatrixType::Scalar>::IsComplex)
+    {
+      VERIFY_EVALUATION_COUNT( use_n_times<3>(2*m1), 0 );
+      VERIFY_EVALUATION_COUNT( use_n_times<4>(2*m1), 1 );
+    }
+    else
+    {
+      VERIFY_EVALUATION_COUNT( use_n_times<1>(2*m1), 0 );
+      VERIFY_EVALUATION_COUNT( use_n_times<2>(2*m1), 1 );
+    }
+    VERIFY_EVALUATION_COUNT( use_n_times<2>(m1+m1), 0 );
+    VERIFY_EVALUATION_COUNT( use_n_times<3>(m1+m1), 1 );
+    VERIFY_EVALUATION_COUNT( use_n_times<1>(m1*m1.transpose()), 1 );
+    VERIFY_EVALUATION_COUNT( use_n_times<2>(m1*m1.transpose()), 1 );
+  }
+
+  {
+    VERIFY( verify_eval_type<10>(m1, m1) );
+    if(!NumTraits<typename MatrixType::Scalar>::IsComplex)
+    {
+      VERIFY( verify_eval_type<3>(2*m1, 2*m1) );
+      VERIFY( verify_eval_type<4>(2*m1, m1) );
+    }
+    else
+    {
+      VERIFY( verify_eval_type<1>(2*m1, 2*m1) );
+      VERIFY( verify_eval_type<2>(2*m1, m1) );
+    }
+    VERIFY( verify_eval_type<2>(m1+m1, m1+m1) );
+    VERIFY( verify_eval_type<3>(m1+m1, m1) );
+    VERIFY( verify_eval_type<1>(m1*m1.transpose(), m1) );
+    VERIFY( verify_eval_type<1>(m1*(m1+m1).transpose(), m1) );
+    VERIFY( verify_eval_type<2>(m1*m1.transpose(), m1) );
+  }
+}
+
+
 void test_nesting_ops()
 {
-  CALL_SUBTEST_1(run_nesting_ops(MatrixXf::Random(25,25)));
-  CALL_SUBTEST_2(run_nesting_ops(MatrixXd::Random(25,25)));
-  CALL_SUBTEST_3(run_nesting_ops(Matrix4f::Random()));
-  CALL_SUBTEST_4(run_nesting_ops(Matrix4d::Random()));
+  CALL_SUBTEST_1(run_nesting_ops_1(MatrixXf::Random(25,25)));
+  CALL_SUBTEST_2(run_nesting_ops_1(MatrixXcd::Random(25,25)));
+  CALL_SUBTEST_3(run_nesting_ops_1(Matrix4f::Random()));
+  CALL_SUBTEST_4(run_nesting_ops_1(Matrix2d::Random()));
+
+  CALL_SUBTEST_1( run_nesting_ops_2(MatrixXf(internal::random<int>(1,EIGEN_TEST_MAX_SIZE), internal::random<int>(1,EIGEN_TEST_MAX_SIZE))) );
+  CALL_SUBTEST_2( run_nesting_ops_2(MatrixXcd(internal::random<int>(1,EIGEN_TEST_MAX_SIZE), internal::random<int>(1,EIGEN_TEST_MAX_SIZE))) );
+  CALL_SUBTEST_3( run_nesting_ops_2(Matrix4f()) );
+  CALL_SUBTEST_4( run_nesting_ops_2(Matrix2d()) );
+
 }