Workaround for misalignment of SubmapSlice and Eigen data structures in heterogeneous builds
#1910
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- Added a workaround for misaligned SubmapSlice structure between cartographer and cartographer_ros built using different compilers or compile contexts - Rearranged SubmapSlice field order after static analysis performed with clangd - Added commented non-portable workaround with \#pragma pack - Closes cartographer-project#1909 Signed-off-by: Andrey Vukolov <[email protected]>
twdragon
changed the title
SubmapSlice in heterogeneous buildsSubmapSlice in heterogeneous builds
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This issue persists also in other parts of the project, so I will continue the investigation |
- Adopted C++17 standard, removed CXX standard requirement - Removed Abseil's absl::unique_ptr in favour of std::unique_ptr producing errors when built on Ubuntu 22 with fresh Abseil built from source - Added DISABLE_AVX_ALIGNMENT CMake option to prevent Eigen (especially built from source) from misalignment of the data structures passed outside the library namespace on the machines with modern CPUs providing AVX vectorization out of the box - Tested on Intel Core-i7 6700, any performance decreaseing was not discovered Signed-off-by: Andrey Vukolov <[email protected]>
twdragon
changed the title
SubmapSlice in heterogeneous buildsSubmapSlice and Eigen data structures in heterogeneous builds
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Updated involving the |
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Due to different structure alignment rules in different compilers (or even the same compiler in different compiling contexts), the
SubmapSlicestructure defined in ./cartographer/io/submap_painter.h comes intocartographer_rosor another external project misaligned by 48 bytes because of differentsizeof()return values (224 vs 256 bytes). This behaviour is proven when testing Cartographer compiled using Clang 15 and GCC 11.3 on Mint Linux 22 with a customized build of ROS. The reason is deeply sitting problem with implementation-defined STL shipped with different kernels and build pipelines. This pull request adds a semi-portable workaround for this issue forcing alignment ofSubmapSlicestructure to 32 bytes as is required by GCC.#pragma packfree()oncairo_data#1909