Clear nested candidates in select if certainty is yes #141927

compiler-errors · 2025-06-02T18:01:05Z

Proving these goals is redundant.

compiler-errors · 2025-06-02T18:01:10Z

@bors2 try @rust-timer queue

rust-bors · 2025-06-02T18:01:13Z

⌛ Trying commit 47dbfcd with merge c60b339…

[PERF] Clear nested candidates in select if certainty is yes r? `@ghost`

rust-bors · 2025-06-02T20:31:06Z

☀️ Try build successful (CI)
Build commit: c60b339 (c60b3390f6b226dae0b82633f7296f0b46664be9)

rust-timer · 2025-06-03T17:01:15Z

Finished benchmarking commit (c60b339): comparison URL.

Overall result: ✅ improvements - no action needed

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.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.8%	[-1.9%, -0.4%]	7
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (secondary 0.1%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	1.7%	[0.4%, 3.1%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.8%	[-1.2%, -0.5%]	7
All ❌✅ (primary)	-	-	0

Cycles

Results (secondary -0.7%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.6%	[0.4%, 0.7%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.0%	[-1.8%, -0.6%]	9
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 743.192s -> 741.915s (-0.17%)
Artifact size: 372.27 MiB -> 372.25 MiB (-0.01%)

compiler-errors · 2025-06-03T17:26:14Z

Minor perf improvement...

r? lcnr

rustbot · 2025-06-03T17:26:16Z

Some changes occurred to the core trait solver

cc @rust-lang/initiative-trait-system-refactor

lcnr · 2025-06-03T20:43:22Z

compiler/rustc_trait_selection/src/solve/select.rs

@@ -159,6 +160,12 @@ fn to_selection<'tcx>(
        })
        .collect();

+    // Drop nested goals from selection since they can't constrain the impl args
+    // further if they're unambiguous.
+    if let Ok(Certainty::Yes) = cand.result() {


why not move this check higher up so that we don't even instantiate them if we've got Certainty::Yes. I can imagine that only instantiating the opt impl args would give us another 1-2%

compiler-errors · 2025-06-03T21:14:27Z

@bors2 try parent=last @rust-timer queue

rust-bors · 2025-06-03T21:14:31Z

⌛ Trying commit 75b8312 with merge 36ffb8f…

To cancel the try build, run the command @bors2 try cancel.

[PERF] Clear nested candidates in select if certainty is yes Proving these goals is redundant.

compiler-errors · 2025-06-03T21:16:12Z

@bors2 try cancel

rust-bors · 2025-06-03T21:16:14Z

Try build cancelled. Cancelled workflows:

https://github.com/rust-lang/rust/actions/runs/15428008242

compiler-errors · 2025-06-03T21:18:02Z

@bors2 try parent=last @rust-timer queue

rust-timer · 2025-06-04T06:20:32Z

Finished benchmarking commit (95d796f): comparison URL.

Overall result: ✅ improvements - no action needed

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.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.5%	[-19.7%, -0.3%]	9
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary -10.9%, secondary -1.0%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.6%	[0.5%, 0.8%]	4
Improvements ✅ (primary)	-10.9%	[-10.9%, -10.9%]	1
Improvements ✅ (secondary)	-1.6%	[-4.8%, -0.4%]	12
All ❌✅ (primary)	-10.9%	[-10.9%, -10.9%]	1

Cycles

Results (secondary -1.0%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.8%	[0.4%, 1.7%]	11
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.2%	[-18.3%, -0.5%]	9
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 743.192s -> 742.72s (-0.06%)
Artifact size: 372.27 MiB -> 372.22 MiB (-0.01%)

compiler-errors · 2025-06-04T12:55:12Z

seriously?? haha

@bors try @rust-timer queue

[PERF] Clear nested candidates in select if certainty is yes Proving these goals is redundant.

bors · 2025-06-04T12:56:29Z

⌛ Trying commit 1afd323 with merge 38419ce...

bors · 2025-06-04T15:25:12Z

☀️ Try build successful - checks-actions
Build commit: 38419ce (38419ce1639bf75d983cee1d879c0425821cfb52)

rust-timer · 2025-06-04T18:21:46Z

Finished benchmarking commit (38419ce): comparison URL.

Overall result: ✅ improvements - no action needed

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.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.2%	[-19.8%, -0.4%]	10
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (secondary -1.0%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	1.2%	[1.2%, 1.2%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.1%	[-3.1%, -3.1%]	1
All ❌✅ (primary)	-	-	0

Cycles

Results (secondary -1.1%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	3.0%	[1.7%, 3.6%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-17.5%	[-17.5%, -17.5%]	1
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 748.459s -> 749.441s (0.13%)
Artifact size: 371.85 MiB -> 371.84 MiB (-0.00%)

lcnr · 2025-06-05T08:24:32Z

compiler/rustc_trait_selection/src/solve/inspect/analyse.rs

+        let param_env = self.goal.goal.param_env;
+        let mut orig_values = self.goal.orig_values.to_vec();
+
+        let mut opt_impl_args = None;


vibeck:

change this to fn instantiate_impl_args and eagerly return (after instantiating the final state + dealing with the term hack) if there's a inspect::ProbeStep::RecordImplArgs and then unreachable!() after the for?

lcnr · 2025-06-05T08:25:19Z

that is... something

r=me after nit

compiler-errors · 2025-06-05T21:20:07Z

Not sure if this is exactly what u wanted, but I'd rather tweak this later since I want to land this.

@bors r=lcnr rollup=never

bors · 2025-06-05T21:20:09Z

📌 Commit 1e5cd12 has been approved by lcnr

It is now in the queue for this repository.

lcnr · 2025-06-06T09:15:52Z

this isn't quite what I want, but we can merge and change it later myself 😁

bors · 2025-06-07T15:26:37Z

⌛ Testing commit 1e5cd12 with merge 2f2c8c3...

bors · 2025-06-07T18:27:06Z

☀️ Test successful - checks-actions
Approved by: lcnr
Pushing 2f2c8c3 to master...

github-actions · 2025-06-07T18:30:20Z

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing 5e0bdaa (parent) -> 2f2c8c3 (this PR)

Test differences

No test diffs found

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 2f2c8c3512e82e4315db83bbb53eb79e2c566270 --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

dist-x86_64-apple: 7169.0s -> 9327.4s (30.1%)
mingw-check-2: 1856.0s -> 2133.1s (14.9%)
x86_64-rust-for-linux: 2500.6s -> 2762.8s (10.5%)
dist-arm-linux-musl: 5574.5s -> 5020.4s (-9.9%)
aarch64-gnu-debug: 3516.1s -> 3800.2s (8.1%)
dist-aarch64-apple: 4887.9s -> 5274.7s (7.9%)
x86_64-gnu-llvm-19-2: 5502.4s -> 5885.6s (7.0%)
i686-msvc-2: 7486.3s -> 6975.7s (-6.8%)
dist-x86_64-netbsd: 4822.7s -> 4497.4s (-6.7%)
dist-loongarch64-musl: 4757.8s -> 5071.2s (6.6%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

rust-timer · 2025-06-07T19:55:27Z

Finished benchmarking commit (2f2c8c3): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.5%	[-20.7%, -0.4%]	11
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (secondary 1.0%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	4.9%	[4.9%, 4.9%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.8%	[-2.8%, -2.8%]	1
All ❌✅ (primary)	-	-	0

Cycles

Results (secondary -5.3%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-5.3%	[-19.0%, -2.4%]	6
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 753.141s -> 752.958s (-0.02%)
Artifact size: 372.46 MiB -> 372.44 MiB (-0.01%)

rustbot added T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. WG-trait-system-refactor The Rustc Trait System Refactor Initiative (-Znext-solver) labels Jun 2, 2025

This comment has been minimized.

Sign in to view

rust-bors bot added a commit that referenced this pull request Jun 2, 2025

Auto merge of #141927 - compiler-errors:perf-select, r=<try>

c60b339

[PERF] Clear nested candidates in select if certainty is yes r? `@ghost`

rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jun 2, 2025

This comment has been minimized.

Sign in to view

rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jun 3, 2025

compiler-errors force-pushed the perf-select branch from 47dbfcd to eba03a1 Compare June 3, 2025 17:26

compiler-errors marked this pull request as ready for review June 3, 2025 17:26

rustbot added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jun 3, 2025

rustbot assigned lcnr Jun 3, 2025

lcnr reviewed Jun 3, 2025

View reviewed changes

compiler-errors force-pushed the perf-select branch from eba03a1 to 75b8312 Compare June 3, 2025 21:13

This comment has been minimized.

Sign in to view

rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jun 3, 2025

rust-bors bot added a commit that referenced this pull request Jun 3, 2025

Auto merge of #141927 - compiler-errors:perf-select, r=<try>

36ffb8f

[PERF] Clear nested candidates in select if certainty is yes Proving these goals is redundant.

compiler-errors force-pushed the perf-select branch from 75b8312 to a0971b8 Compare June 3, 2025 21:17

This comment has been minimized.

Sign in to view

rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jun 4, 2025

This comment has been minimized.

Sign in to view

rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jun 4, 2025

bors added a commit that referenced this pull request Jun 4, 2025

Auto merge of #141927 - compiler-errors:perf-select, r=<try>

38419ce

[PERF] Clear nested candidates in select if certainty is yes Proving these goals is redundant.

This comment has been minimized.

Sign in to view

compiler-errors force-pushed the perf-select branch from 1afd323 to 9f0e50c Compare June 4, 2025 16:19

rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jun 4, 2025

lcnr reviewed Jun 5, 2025

View reviewed changes

compiler-errors added 2 commits June 5, 2025 21:18

Clear nested candidates in select if certainty is yes

dcf22aa

Only instantiate impl args

1e5cd12

compiler-errors force-pushed the perf-select branch from 9f0e50c to 1e5cd12 Compare June 5, 2025 21:19

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jun 5, 2025

compiler-errors changed the title ~~[PERF] Clear nested candidates in select if certainty is yes~~ Clear nested candidates in select if certainty is yes Jun 6, 2025

bors added the merged-by-bors This PR was explicitly merged by bors. label Jun 7, 2025

bors merged commit 2f2c8c3 into rust-lang:master Jun 7, 2025
11 checks passed

rustbot added this to the 1.89.0 milestone Jun 7, 2025

Clear nested candidates in select if certainty is yes #141927

Clear nested candidates in select if certainty is yes #141927

Uh oh!

Conversation

compiler-errors commented Jun 2, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

compiler-errors commented Jun 2, 2025

Uh oh!

This comment has been minimized.

rust-bors bot commented Jun 2, 2025

Uh oh!

This comment has been minimized.

rust-bors bot commented Jun 2, 2025

Uh oh!

This comment has been minimized.

rust-timer commented Jun 3, 2025

Overall result: ✅ improvements - no action needed

Uh oh!

compiler-errors commented Jun 3, 2025

Uh oh!

rustbot commented Jun 3, 2025

Uh oh!

Choose a reason for hiding this comment

Uh oh!

compiler-errors commented Jun 3, 2025

Uh oh!

This comment has been minimized.

rust-bors bot commented Jun 3, 2025

Uh oh!

compiler-errors commented Jun 3, 2025

Uh oh!

rust-bors bot commented Jun 3, 2025

Uh oh!

compiler-errors commented Jun 3, 2025

Uh oh!

This comment has been minimized.

rust-timer commented Jun 4, 2025

Overall result: ✅ improvements - no action needed

Uh oh!

compiler-errors commented Jun 4, 2025

Uh oh!

This comment has been minimized.

bors commented Jun 4, 2025

Uh oh!

bors commented Jun 4, 2025

Uh oh!

This comment has been minimized.

rust-timer commented Jun 4, 2025

Overall result: ✅ improvements - no action needed

Uh oh!

Choose a reason for hiding this comment

Uh oh!

lcnr commented Jun 5, 2025

Uh oh!

compiler-errors commented Jun 5, 2025

Uh oh!

bors commented Jun 5, 2025

Uh oh!

lcnr commented Jun 6, 2025

Uh oh!

bors commented Jun 7, 2025

Uh oh!

bors commented Jun 7, 2025

Uh oh!

Uh oh!

github-actions bot commented Jun 7, 2025

Test differences

Job duration changes

Uh oh!

rust-timer commented Jun 7, 2025

Overall result: ✅ improvements - no action needed

Uh oh!

Uh oh!

compiler-errors commented Jun 2, 2025 •

edited

Loading