Fix dpl result difference in cmake vs bazel #9174
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Fix PQ_entry for determinism. Equidistant points were comparing as equal and varying in order by compiler. There is no need for operator== as priority_queue only cares about operator>. QOR is impacted due to different placement results. Signed-off-by: Matt Liberty <[email protected]>
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Code Review
This pull request addresses a non-determinism issue in the detailed placer, which caused different results between cmake and bazel builds. The fix is implemented in src/dpl/src/Place.cpp by ensuring a stable sort order for the priority queue used in the searchNearestSite function. This is achieved by adding a sequence number as a tie-breaker for elements with the same Manhattan distance. This is a correct and robust solution for this class of non-determinism issues. The pull request also diligently updates numerous test output files to match the new deterministic results, which is excellent. The changes are well-contained and look good.
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clang-tidy review says "All clean, LGTM! 👍" |
Signed-off-by: Matt Liberty <[email protected]>
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clang-tidy review says "All clean, LGTM! 👍" |
Now that the compiler difference is resolved in The-OpenROAD-Project#9174 Signed-off-by: Matt Liberty <[email protected]>
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