Merge the two depkind vtables

[cjgillot]

Knowledge of DepKinds is managed using two arrays containing flags (is_anon, eval_always, fingerprint_style), and function pointers (forcing and loading code).

This PR aims at merging the two arrays so as to reduce unneeded indirect calls and (hopefully) increase code locality.
r? @ghost

[cjgillot]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[bors]

⌛ Trying commit daeb774d905256f876441a02b67374f79ee99370 with merge 9311997381062f445ad1b8d25c99e8fc41762ccf...

[bors]

☀️ Try build successful - checks-actions
Build commit: 9311997381062f445ad1b8d25c99e8fc41762ccf (9311997381062f445ad1b8d25c99e8fc41762ccf)

[rust-timer]

Queued 9311997381062f445ad1b8d25c99e8fc41762ccf with parent 12b5bce, future comparison URL.

[rust-timer]

Finished benchmarking commit (9311997381062f445ad1b8d25c99e8fc41762ccf): comparison url.

Summary: This change led to moderate relevant mixed results 🤷 in compiler performance.

• Moderate improvement in instruction counts (up to -1.6% on incr-unchanged builds of helloworld)
• Moderate regression in instruction counts (up to 0.5% on incr-unchanged builds of stm32f4)

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 led 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

[cjgillot]

r? @Mark-Simulacrum

[Mark-Simulacrum]

Overall looks fine to me -- the performance regressions seem likely to be just reshuffling of optimization choices, and don't seem worth additional investigation in my opinion. There's a bunch of improvements in there as well. If we were to try and investigate I'd suggest splitting this PR up -- I think there's several commits which aren't necessarily tied into the primary goal.

I am happy to r=me with the one debug_assert nit fixed.

[bors]

☔ The latest upstream changes (presumably #89933) made this pull request unmergeable. Please resolve the merge conflicts.

[Mark-Simulacrum]

r=me when rebased, I think the perf regression noted here is mostly down to this code being very sensitive and so hard to get just improvements in. The improvements seem larger than the regressions, and this is a good cleanup, so I'm OK proceeding.

[cjgillot]

@bors r=Mark-Simulacrum

[bors]

📌 Commit b11ec29 has been approved by Mark-Simulacrum

[bors]

⌛ Testing commit b11ec29 with merge efd0483...

[bors]

☀️ Test successful - checks-actions
Approved by: Mark-Simulacrum
Pushing efd0483 to master...

[rust-timer]

Finished benchmarking commit (efd0483): comparison url.

Summary: This change led to moderate relevant mixed results 🤷 in compiler performance.

• Moderate improvement in instruction counts (up to -2.0% on incr-unchanged builds of helloworld)
• Moderate regression in instruction counts (up to 0.9% on incr-unchanged builds of clap-rs)

If you disagree with this performance assessment, please file an issue in rust-lang/rustc-perf.

Next Steps: If you can justify the regressions found in this perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please open an issue or create a new PR that fixes the regressions, add a comment linking to the newly created issue or PR, and then add the perf-regression-triaged label to this PR.

@rustbot label: +perf-regression

[Mark-Simulacrum]

Marking as triaged per earlier comments, final results seem consistent with earlier ones.

@rustbot label +perf-regression-triaged