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[CSSPGO][llvm-profgen] Report samples for untrackable frames.

Authored by hoy on May 21 2021, 5:44 PM.

Description

[CSSPGO][llvm-profgen] Report samples for untrackable frames.

Fixing an issue where samples collected for an untrackable frame is not reported. An untrackable frame refers to a frame whose caller is untrackable due to missing debug info or pseudo probe. Though the frame is connected to its parent frame through the frame pointer chain at runtime, the compiler cannot build the connection without debug info or pseudo probe. In such case we just need to report the untrackable frame as the base frame and all of its child frames.

With more samples reported I'm seeing this improves the performance of an internal benchmark by 2.5%.

Reviewed By: wenlei, wlei

Differential Revision: https://reviews.llvm.org/D102961

Details

Committed
hoyMay 24 2021, 12:39 PM
Reviewer
wenlei
Differential Revision
D102961: [CSSPGO][llvm-profgen] Report samples for untrackable frames.
Parents
rG7cd07d339022: fix up test from D102742
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