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e6f1104b57
* extend PartialRedux::cross() to any matrix sizes with automatic vectorization when possible * unit tests: add "geo_" prefix to all unit tests related to the geometry module and start splitting the big "geometry.cpp" tests to multiple smaller ones (also include new tests)
78 lines
2.8 KiB
Plaintext
78 lines
2.8 KiB
Plaintext
namespace Eigen {
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/** \page UnalignedArrayAssert Troubleshooting - Explanation of the assertion on unaligned arrays
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Hello! You are seeing this webpage because your program terminated on an assertion failure like this one:
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<pre>
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my_program: path/to/eigen2/Eigen/src/Core/MatrixStorage.h:44:
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Eigen::ei_matrix_array<T, Size, MatrixOptions, Align>::ei_matrix_array()
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[with T = double, int Size = 2, int MatrixOptions = 2, bool Align = true]:
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Assertion `(reinterpret_cast<size_t>(array) & 0xf) == 0 && "this assertion
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is explained here: http://eigen.tuxfamily.org/dox/UnalignedArrayAssert.html
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**** READ THIS WEB PAGE !!! ****"' failed.
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</pre>
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There are 3 known causes for this issue. Please read on to understand them and learn how to fix them.
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\b Table \b of \b contents
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- \ref c1
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- \ref c2
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- \ref c3
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- \ref explanation
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\section c1 Cause 1: Structures having Eigen objects as members
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If you have code like this,
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\code
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class Foo
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{
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//...
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Eigen::Vector2d v;
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//...
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};
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//...
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Foo *foo = new Foo;
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\endcode
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then you need to read this separate page: \ref StructHavingEigenMembers "Structures Having Eigen Members".
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Note that here, Eigen::Vector2d is only used as an example, more generally the issue arises for all \ref FixedSizeVectorizable "fixed-size vectorizable Eigen types".
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\section c2 Cause 2: STL Containers
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If you use STL Containers such as std::vector, std::map, ..., with Eigen objects, like this,
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\code
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std::vector<Eigen::Matrix2f> my_vector;
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std::map<int, Eigen::Matrix2f> my_map;
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\endcode
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then you need to read this separate page: \ref StlContainers "Using STL Containers with Eigen".
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Note that here, Eigen::Matrix2f is only used as an example, more generally the issue arises for all \ref FixedSizeVectorizable "fixed-size vectorizable Eigen types" and \ref StructHavingEigenMembers "structures having such Eigen objects as member".
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\section c3 Cause 3: Passing Eigen objects by value
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If some function in your code is getting an Eigen object passed by value, like this,
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\code
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void func(Eigen::Vector4d v);
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\endcode
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then you need to read this separate page: \ref PassingByValue "Passing Eigen objects by value to functions".
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Note that here, Eigen::Vector4d is only used as an example, more generally the issue arises for all \ref FixedSizeVectorizable "fixed-size vectorizable Eigen types".
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\section explanation General explanation of this assertion
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\ref FixedSizeVectorizable "fixed-size vectorizable Eigen objects" must absolutely be created at 16-byte-aligned locations, otherwise SIMD instructions adressing them will crash.
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Eigen normally takes care of these alignment issues for you, by setting an alignment attribute on them and by overloading their "operator new".
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However there are a few corner cases where these alignment settings get overridden: they are the possible causes for this assertion.
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*/
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}
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