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internal iteration for `&mut I`
this pr implements internal iteration for &mut I when I: Sized. it additionally inlines some wrapper functions that were not previously inline, which seems to speed things up by a fair amount in some cases.
this lead to up to 3x performance gains across the board for iter:: benches, with only a minor regression for iter::bench_filter_sum
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:hourglass: Trying commit cb7f7ee07f6d67e36cc08b337c034f5e81343dc1 with merge 3e685715a7ece536b2ab653e3433c06c00454bdf...
:sunny: Try build successful - checks-actions
Build commit: 3e685715a7ece536b2ab653e3433c06c00454bdf (3e685715a7ece536b2ab653e3433c06c00454bdf)
Queued 3e685715a7ece536b2ab653e3433c06c00454bdf with parent d77da9da84fc89908ad01578c33c2dca8f597ffe, future comparison URL.
Finished benchmarking commit (3e685715a7ece536b2ab653e3433c06c00454bdf): comparison url.
Instruction count
- Primary benchmarks: mixed results
- Secondary benchmarks: mixed results
| mean[^1] | max | count[^2] | |
|---|---|---|---|
| Regressions 😿 (primary) |
0.8% | 25.3% | 66 |
| Regressions 😿 (secondary) |
0.6% | 1.9% | 32 |
| Improvements 🎉 (primary) |
-0.5% | -1.5% | 14 |
| Improvements 🎉 (secondary) |
-0.6% | -1.4% | 22 |
| All 😿🎉 (primary) | 0.6% | 25.3% | 80 |
Max RSS (memory usage)
Results
- Primary benchmarks: 🎉 relevant improvement found
- Secondary benchmarks: mixed results
| mean[^1] | max | count[^2] | |
|---|---|---|---|
| Regressions 😿 (primary) |
N/A | N/A | 0 |
| Regressions 😿 (secondary) |
4.0% | 4.0% | 1 |
| Improvements 🎉 (primary) |
-2.3% | -2.3% | 1 |
| Improvements 🎉 (secondary) |
-2.5% | -2.5% | 1 |
| All 😿🎉 (primary) | -2.3% | -2.3% | 1 |
Cycles
Results
- Primary benchmarks: 😿 relevant regressions found
- Secondary benchmarks: 😿 relevant regressions found
| mean[^1] | max | count[^2] | |
|---|---|---|---|
| Regressions 😿 (primary) |
14.7% | 37.5% | 3 |
| Regressions 😿 (secondary) |
2.8% | 3.0% | 2 |
| Improvements 🎉 (primary) |
N/A | N/A | 0 |
| Improvements 🎉 (secondary) |
N/A | N/A | 0 |
| All 😿🎉 (primary) | 14.7% | 37.5% | 3 |
[^1]: the arithmetic mean of the percent change [^2]: number of relevant changes
If you disagree with this performance assessment, please file an issue in rust-lang/rustc-perf.
Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.
Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.
@bors rollup=never @rustbot label: +S-waiting-on-review -S-waiting-on-perf +perf-regression
Presumably this makes compilation slower, but the perf tests don't show the effect on the performance of the compiled code, right?
Other than the std benches (which aren't great) we don't have anything automated to assess runtime performance. In the rustc-perf suite check and doc builds are the closest since they don't codegen but they're probably not diverse enough.
You could try paring down the PR by splitting out some of the changes. E.g. some of the inlining in function.rs doesn't look relevant to iterators. You can also run rustc-perf locally and focus on that one benchmark, that should yield results more quickly (assuming you have a machine that can compile a stage1 rustc in a reasonable amount of time).
rustc-perf seems to take forever on my machine and i can't display the results after it's finished. so that doesn't seem like a good option for me :/
It can be set to run a subset of the benchmarks, e.g. the serde ones. https://github.com/rust-lang/rustc-perf/tree/master/collector#benchmarking-options Running the site locally should work as long as it uses the same DB as generated by the collector.
thanks for the tips! i managed to get it working thanks to your help. it seems that the biggest culprit was inlining the ops::function wrappers.
but even without it i still get a 1-2% regression on deeply-nested-multi
I'm going to send this over to
r? @m-ou-se
because I think this is going to be as much a policy decision (about compile-vs-runtime) as it is about the code itself.
Some changes were reverted, let's get new perf results.
@bors try @rust-timer queue
:hourglass: Trying commit f6a3462bda206ae937ff83760bf0d359fb2ddf0e with merge c20ee6d211784a78b94e26d37cce4e66acea976a...
:sunny: Try build successful - checks-actions
Build commit: c20ee6d211784a78b94e26d37cce4e66acea976a (c20ee6d211784a78b94e26d37cce4e66acea976a)
Queued c20ee6d211784a78b94e26d37cce4e66acea976a with parent aeb5067967ef58e4a324b19dd0dba2f385d5959f, future comparison URL.
Finished benchmarking commit (c20ee6d211784a78b94e26d37cce4e66acea976a): comparison url.
Instruction count
- Primary benchmarks: mixed results
- Secondary benchmarks: ❌ relevant regressions found
| mean[^1] | max | count[^2] | |
|---|---|---|---|
| Regressions ❌ (primary) |
0.2% | 0.3% | 14 |
| Regressions ❌ (secondary) |
0.7% | 2.0% | 16 |
| Improvements ✅ (primary) |
-0.4% | -0.7% | 7 |
| Improvements ✅ (secondary) |
- | - | 0 |
| All ❌✅ (primary) | 0.0% | -0.7% | 21 |
Max RSS (memory usage)
Results
- Primary benchmarks: no relevant changes found
- Secondary benchmarks: mixed results
| mean[^1] | max | count[^2] | |
|---|---|---|---|
| Regressions ❌ (primary) |
- | - | 0 |
| Regressions ❌ (secondary) |
2.4% | 4.5% | 8 |
| Improvements ✅ (primary) |
- | - | 0 |
| Improvements ✅ (secondary) |
-3.4% | -4.2% | 3 |
| All ❌✅ (primary) | - | - | 0 |
Cycles
Results
- Primary benchmarks: ✅ relevant improvement found
- Secondary benchmarks: ✅ relevant improvement found
| mean[^1] | max | count[^2] | |
|---|---|---|---|
| Regressions ❌ (primary) |
- | - | 0 |
| Regressions ❌ (secondary) |
- | - | 0 |
| Improvements ✅ (primary) |
-2.3% | -2.3% | 1 |
| Improvements ✅ (secondary) |
-4.1% | -4.1% | 1 |
| All ❌✅ (primary) | -2.3% | -2.3% | 1 |
[^1]: the arithmetic mean of the percent change [^2]: number of relevant changes
If you disagree with this performance assessment, please file an issue in rust-lang/rustc-perf.
Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.
Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.
@bors rollup=never @rustbot label: +S-waiting-on-review -S-waiting-on-perf +perf-regression
The compile-time perf numbers are slightly negative, but less so than the previous attempt to do this.
But we need some runtime benchmark numbers to verify that it brings the expected benefits. There are some core::iter benchmarks that I'd expect to show some speedup.
@rustbot author
Closing this as inactive. Feel free to reöpen this pr or create a new pr if you get the time to work on this. Thanks