Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Work around strange gcc bug #363

Merged
merged 1 commit into from
Aug 22, 2023
Merged

Conversation

miscco
Copy link
Collaborator

@miscco miscco commented Aug 22, 2023

We have consistent CI failures, where gcc 12 believes we would be writing out of bound elements.

That warning only happens with gcc 12 and goes away if we write one element more...

@miscco miscco requested review from a team as code owners August 22, 2023 12:32
@miscco miscco requested review from alliepiper and ericniebler and removed request for a team August 22, 2023 12:32
@miscco miscco added thrust For all items related to Thrust. bug Something isn't working right. infrastructure Shared CMake, github, etc infrastructure labels Aug 22, 2023
Copy link
Collaborator

@jrhemstad jrhemstad left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Any idea how this came up? We didn't update the gcc version or any build flags, nor do I think we updated anything that would interact with this code, so I'm confused about how this just started happening.

@miscco
Copy link
Collaborator Author

miscco commented Aug 22, 2023

It is a highly volatile backend misscompilation involving the vectorizer via -O3

It had been coming up from time to time infrequently, so I believe any arbitrary change in one of our headers could trigger it

@miscco miscco merged commit c057856 into NVIDIA:main Aug 22, 2023
437 checks passed
@miscco miscco deleted the thrust_string_overflow branch August 22, 2023 16:34
@griwes
Copy link
Collaborator

griwes commented Aug 22, 2023

Ah yes, that bug. I had it narrowed down to a single commit in GCC history at some point, but was never able to create a reproducer that was a reasonable reproducer to submit to upstream 🙃

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
bug Something isn't working right. infrastructure Shared CMake, github, etc infrastructure thrust For all items related to Thrust.
Projects
Archived in project
Development

Successfully merging this pull request may close these issues.

3 participants