Page MenuHomePhabricator

BPF: add a test for selectiondag alias analysis w.r.t. lifetime
ClosedPublic

Authored by yonghong-song on Dec 1 2020, 7:43 PM.

Details

Summary

This adds a test for bug:

https://bugs.llvm.org/show_bug.cgi?id=47591

Previously, selection dag has a bug which may incorrectly
assume no alias when crossing a lifetime boundary and this
may generate incorrect code as demonstrated in the above bug.

It looks the bug is fixed by https://reviews.llvm.org/D91833.
Basically, when comparing two potential memory access dag nodes,

a store and a lifetime.start,

with the same frame index.
Previously, it may be decided no alias. With the above fix,
these two will be considered aliasing which will prevent
incorrect code scheduling.

Diff Detail

Event Timeline

yonghong-song created this revision.Dec 1 2020, 7:43 PM
Herald added a project: Restricted Project. · View Herald TranscriptDec 1 2020, 7:43 PM
yonghong-song requested review of this revision.Dec 1 2020, 7:43 PM
yonghong-song edited the summary of this revision. (Show Details)Dec 1 2020, 7:51 PM
ast accepted this revision.Dec 1 2020, 8:19 PM
This revision is now accepted and ready to land.Dec 1 2020, 8:19 PM
This revision was landed with ongoing or failed builds.Dec 2 2020, 10:27 PM
This revision was automatically updated to reflect the committed changes.