[pmo] Re-apply load [copy] fixes eliminating some non-determinism that came up. #28314
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…ing bisection code. Specifically, I was abusing some sorting behavior on some arrays that I really needed to iterate over == non-determinism. To work around these issues, I made two changes: 1. Rather than using a bit vector to mark copy_values that were handled as part of phi handling and thus needing a way to map copy_value -> bit vector index, I instead just added a separate small ptr set called copyValueProcessedWithPhiNodes. 2. I refactored/changed how copy cleanups were inserted for phi nodes by constructing a flat 2d-array that is stable sorted by the index of the incoming value associated with the cleanups. An incoming value's index is the count of the copy cleanup when we see it for the first time. Thus when we do the stable sort we will be visiting in cleanup insertion order and also will be doing insertion order along the incomingValue axis.
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I tested this locally and it eliminated these issues for me. |
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@swift-ci test |
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@swift-ci asan test |
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preset=buildbot,tools=R,stdlib=RD |
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@brentdax I started off a custom preset job that should run the same preset as the bot did. So we can be sure it doesnt happen. |
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I reapplied and put the commit that eliminated the non-determinism on top. The commit msg for that commit is:
[pmo] Eliminate non-determinism by unmixing some iteration order/sorting bisection code.
Specifically, I was abusing some sorting behavior on some arrays that I really
needed to iterate over == non-determinism. To work around these issues, I made
two changes:
Rather than using a bit vector to mark copy_values that were handled as part
of phi handling and thus needing a way to map copy_value -> bit vector index, I
instead just added a separate small ptr set called
copyValueProcessedWithPhiNodes.
I refactored/changed how copy cleanups were inserted for phi nodes by
constructing a flat 2d-array that is stable sorted by the index of the incoming
value associated with the cleanups. An incoming value's index is the count of
the copy cleanup when we see it for the first time. Thus when we do the stable
sort we will be visiting in cleanup insertion order and also will be doing
insertion order along the incomingValue axis.
rdar://57257309