Skip to content

Improve merge_from_succ - #68790

Merged
bors merged 2 commits into
rust-lang:masterfrom
nnethercote:improve-merge_from_succ
Feb 6, 2020
Merged

Improve merge_from_succ#68790
bors merged 2 commits into
rust-lang:masterfrom
nnethercote:improve-merge_from_succ

Conversation

@nnethercote

@nnethercotennethercote commented Feb 3, 2020

Copy link
Copy Markdown
Contributor

A couple of small performance wins.

r? @nikomatsakis

@nnethercote
Fix up merge_from_succ.
0eb297d
This function has a variable `changed` that is erroneously used for two
related-but-different purpose:
- to detect if the current element has changed;
- to detect if any elements have changed.
As a result, its use for the first purpose is broken, because if any
prior element changed then the code always thinks the current element
has changed. This is only a performance bug, not a correctness bug,
because we frequently end up calling `assign_unpacked` unnecessarily to
overwrite the element with itself.
This commit adds `any_changed` to correctly distinguish between the two
purposes. This is a small perf win for some benchmarks.
@nnethercote
Pull out a special case in merge_from_succ.
d62b6f2
This is a small perf win.
@rust-highfiverust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Feb 3, 2020
@nnethercote

nnethercote commented Feb 3, 2020

Copy link
Copy Markdown
ContributorAuthor

@bors try @rust-timer queue

@rust-timer

rust-timer commented Feb 3, 2020

Copy link
Copy Markdown
Collaborator

Awaiting bors try build completion

@bors

bors commented Feb 3, 2020

Copy link
Copy Markdown
Collaborator

⌛ Trying commit d62b6f2 with merge e7835ee33c2030551c58f51ce5ac1f594bfc48d5...

@nnethercote

nnethercote commented Feb 3, 2020

Copy link
Copy Markdown
ContributorAuthor

Some local results:

clap-rs-check
avg: -1.4% min: -1.4% max: -1.4%
inflate-check
avg: -1.2% min: -1.2% max: -1.2%
cranelift-codegen-check
avg: -0.6% min: -0.6% max: -0.6%

@bors

bors commented Feb 3, 2020

Copy link
Copy Markdown
Collaborator

☀️ Try build successful - checks-azure
Build commit: e7835ee33c2030551c58f51ce5ac1f594bfc48d5 (e7835ee33c2030551c58f51ce5ac1f594bfc48d5)

@rust-timer

rust-timer commented Feb 3, 2020

Copy link
Copy Markdown
Collaborator

Queued e7835ee33c2030551c58f51ce5ac1f594bfc48d5 with parent 8f49d46, future comparison URL.

@rust-timer

rust-timer commented Feb 3, 2020

Copy link
Copy Markdown
Collaborator

Finished benchmarking try commit e7835ee33c2030551c58f51ce5ac1f594bfc48d5, comparison URL.

nikomatsakis
nikomatsakis reviewed Feb 3, 2020
View reviewed changes
Comment threadsrc/librustc_passes/liveness.rs
@nnethercote

nnethercote commented Feb 3, 2020

Copy link
Copy Markdown
ContributorAuthor

@bors r=nikomatsakis

@bors

bors commented Feb 3, 2020

Copy link
Copy Markdown
Collaborator

📌 Commit d62b6f2 has been approved by nikomatsakis

@borsbors 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 Feb 3, 2020
@bors

bors commented Feb 4, 2020

Copy link
Copy Markdown
Collaborator

⌛ Testing commit d62b6f2 with merge add3e5105559c64935116c58ee40a635ce39ed8f...

@rust-highfive

rust-highfive commented Feb 4, 2020

Copy link
Copy Markdown
Contributor

Your PR failed (pretty log, raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

@bors

bors commented Feb 4, 2020

Copy link
Copy Markdown
Collaborator

💔 Test failed - checks-azure

@borsbors added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Feb 4, 2020
@nnethercote

nnethercote commented Feb 4, 2020

Copy link
Copy Markdown
ContributorAuthor

Looks like the failure was an infra problem, unrelated to the commits.

@bors retry

@borsbors 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 Feb 4, 2020
Centril added a commit to Centril/rust that referenced this pull request Feb 5, 2020
@Centril
Rollup merge ofrust-lang#68790- nnethercote:improve-merge_from_succ…
a9cc6dc
…, r=nikomatsakis
Improve `merge_from_succ`
A couple of small performance wins.
r? @nikomatsakis
@CentrilCentril mentioned this pull request Feb 5, 2020
Closed
Centril added a commit to Centril/rust that referenced this pull request Feb 5, 2020
@Centril
Rollup merge ofrust-lang#68790- nnethercote:improve-merge_from_succ…
eac6e90
…, r=nikomatsakis
Improve `merge_from_succ`
A couple of small performance wins.
r? @nikomatsakis
@CentrilCentril mentioned this pull request Feb 5, 2020
Closed
Dylan-DPC-zz pushed a commit to Dylan-DPC-zz/rust that referenced this pull request Feb 5, 2020
@Dylan-DPC
Rollup merge ofrust-lang#68790- nnethercote:improve-merge_from_succ…
c177941
…, r=nikomatsakis
Improve `merge_from_succ`
A couple of small performance wins.
r? @nikomatsakis
@Dylan-DPC-zzDylan-DPC-zz mentioned this pull request Feb 5, 2020
Merged
bors added a commit that referenced this pull request Feb 5, 2020
@bors
Auto merge of#68861- Dylan-DPC:rollup-0m09hsg, r=Dylan-DPC
337b2d4
Rollup of 8 pull requests
Successful merges:
- #68762 (Strip unnecessary subexpression)
- #68790 (Improve `merge_from_succ`)
- #68809 (Make more arithmetic functions unstably const)
- #68832 (Clean up E0264, E0267 and E0268 explanations)
- #68840 (On suggesting `#![recursion_limit = "X"]`, note current crate name)
- #68846 (doc fix on doc attribute)
- #68851 (Fix issue number of `capacity` method)
- #68858 (Merge item id stable hashing functions)
Failed merges:
r? @ghost
bors added a commit that referenced this pull request Feb 6, 2020
@bors
Auto merge of#68861- Dylan-DPC:rollup-0m09hsg, r=Dylan-DPC
ed853b8
Rollup of 8 pull requests
Successful merges:
- #68762 (Strip unnecessary subexpression)
- #68790 (Improve `merge_from_succ`)
- #68809 (Make more arithmetic functions unstably const)
- #68832 (Clean up E0264, E0267 and E0268 explanations)
- #68840 (On suggesting `#![recursion_limit = "X"]`, note current crate name)
- #68846 (doc fix on doc attribute)
- #68851 (Fix issue number of `capacity` method)
- #68858 (Merge item id stable hashing functions)
Failed merges:
r? @ghost
@bors
bors merged commit d62b6f2 into rust-lang:masterFeb 6, 2020
@nnethercote
nnethercote deleted the improve-merge_from_succ branch February 6, 2020 21:33
Sign up for freeto join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@nikomatsakisnikomatsakisnikomatsakis left review comments

Assignees

@nikomatsakisnikomatsakis

Labels

S-waiting-on-borsStatus: Waiting on bors to run and complete tests. Bors will change the label on completion.

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

5 participants

@nnethercote@rust-timer@bors@rust-highfive@nikomatsakis