Wasmtime GitHub notifications bot (Jan 09 2021 at 01:32): Wasmtime GitHub notifications bot (Jan 09 2021 at 01:32):cfallin opened PR #2564 from load-coalesce-bug to main:
A branch is considered side-effecting and so updates the instruction
color (which is our way of computing how far instructions can sink).
However, in the lowering loop, we did not update current instruction
color when scanning backward across branches, which are side-effecting.
As a result, the color was stale and fewer load-op merges were permitted
than are actually possible.Note that this would not have resulted in any correctness issues, as the
stale color is too high (so no merges are permitted that should have
been disallowed).Fixes #2562.
<!--
Please ensure that the following steps are all taken care of before submitting
the PR.
[ ] This has been discussed in issue #..., or if not, please tell us why
here.[ ] A short description of what this does, why it is needed; if the
description becomes long, the matter should probably be discussed in an issue
first.[ ] This PR contains test cases, if meaningful.
- [ ] A reviewer from the core maintainer team has been assigned for this PR.
If you don't know who could review this, please indicate so. The list of
suggested reviewers on the right can help you.Please ensure all communication adheres to the code of conduct.
-->
Wasmtime GitHub notifications bot (Jan 09 2021 at 01:32):cfallin requested abrown for a review on PR #2564.
Wasmtime GitHub notifications bot (Jan 11 2021 at 18:18):abrown submitted PR Review.
Wasmtime GitHub notifications bot (Jan 11 2021 at 18:18):abrown submitted PR Review.
Wasmtime GitHub notifications bot (Jan 11 2021 at 18:18):abrown created PR Review Comment:
doc suggestion: it might be useful to tell the reader where to look for branch lowering. It doesn't need to be too specific to be robust against refactoring but I could use a helpful hint to get me looking in the right place.
Wasmtime GitHub notifications bot (Jan 11 2021 at 19:20):cfallin updated PR #2564 from load-coalesce-bug to main:
A branch is considered side-effecting and so updates the instruction
color (which is our way of computing how far instructions can sink).
However, in the lowering loop, we did not update current instruction
color when scanning backward across branches, which are side-effecting.
As a result, the color was stale and fewer load-op merges were permitted
than are actually possible.Note that this would not have resulted in any correctness issues, as the
stale color is too high (so no merges are permitted that should have
been disallowed).Fixes #2562.
<!--
Please ensure that the following steps are all taken care of before submitting
the PR.
[ ] This has been discussed in issue #..., or if not, please tell us why
here.[ ] A short description of what this does, why it is needed; if the
description becomes long, the matter should probably be discussed in an issue
first.[ ] This PR contains test cases, if meaningful.
- [ ] A reviewer from the core maintainer team has been assigned for this PR.
If you don't know who could review this, please indicate so. The list of
suggested reviewers on the right can help you.Please ensure all communication adheres to the code of conduct.
-->
Wasmtime GitHub notifications bot (Jan 11 2021 at 19:20):cfallin submitted PR Review.
Wasmtime GitHub notifications bot (Jan 11 2021 at 19:20):cfallin created PR Review Comment:
Updated, thanks!
Wasmtime GitHub notifications bot (Jan 11 2021 at 20:06):cfallin merged PR #2564.
Last updated: Nov 22 2024 at 16:03 UTC