Reduce number of allocations done by NLL #51617
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| // non-handling of siblings); | ||
| // - ~99% of the time the loop isn't reached, and this code hot, so we | ||
| // don't want to allocate `todo` unnecessarily. | ||
| // the time |
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"the time" here is a dangling fragment.
And since you'll be updating the comment phrasing anyway, i would like it if you added an explicit note that we do not traverse siblings of the input mpi, merely its children. (I believe that's what the comment on push_siblings was trying to do in the previous version in this code.)
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this looks fine to me; I left a nit about a typo in the comments and also about a comment that was deleted that I would like preserved. |
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r? @pnkfelix |
`has_any_child_of` is hot. It allocates a `Vec` that almost always doesn't exceed a length of 1. This patch peels off the first iteration of the loop, avoiding the need for the `Vec` creation in ~99% of cases.
These vectors are always small, so this avoids lots of allocations.
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@pnkfelix: new version is up. I removed the dangling text and tweaked the new comment about siblings. (Note that the old comment about siblings is still present.) |
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@bors r+ rollup |
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📌 Commit ba0bb02 has been approved by |
bors
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Reduce number of allocations done by NLL
A couple of easy wins. Here are the NLL speedups that exceed 1%:
```
sentry-cli-check
avg: -3.5% min: -3.5% max: -3.5%
inflate-check
avg: -1.9% min: -1.9% max: -1.9%
inflate
avg: -1.7% min: -1.7% max: -1.7%
clap-rs-check
avg: -1.6% min: -1.6% max: -1.6%
cargo-check
avg: -1.6% min: -1.6% max: -1.6%
ripgrep-check
avg: -1.4% min: -1.4% max: -1.4%
serde-check
avg: -1.2% min: -1.2% max: -1.2%
regex-check
avg: -1.0% min: -1.0% max: -1.0%
sentry-cli
avg: -1.0% min: -1.0% max: -1.0%
```
r? @nikomatsakis
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☀️ Test successful - status-appveyor, status-travis |
A couple of easy wins. Here are the NLL speedups that exceed 1%:
r? @nikomatsakis