Do not preallocate HirIds

[cjgillot]

Part of #87234

r? @petrochenkov

[cjgillot]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

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

[bors]

⌛ Trying commit 1e2bc75ee45f779de054af223bdd30325a37668a with merge ac53b49b37ce0cecc90dc0c264d8d68270af10af...

[bors]

☀️ Try build successful - checks-actions
Build commit: ac53b49b37ce0cecc90dc0c264d8d68270af10af (ac53b49b37ce0cecc90dc0c264d8d68270af10af)

[rust-timer]

Queued ac53b49b37ce0cecc90dc0c264d8d68270af10af with parent 4878034, future comparison URL.

[rust-timer]

Finished benchmarking try commit (ac53b49b37ce0cecc90dc0c264d8d68270af10af): comparison url.

Summary: ERROR categorizing benchmark run!

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up.

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

[Mark-Simulacrum]

(Perf is now ready)

[petrochenkov]

Aha, here's the style-servo-check regression.

[cjgillot]

This PR also creates a Found unstable fingerprints for opt_def_kind ICE in the incr-patched cherry-pick case. I need to investigate it before this is merged.

[cjgillot]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

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

[bors]

⌛ Trying commit d60bbde with merge 94bf4d541167db3e4c9bf41073fce29fa2e5d3ae...

[bors]

☀️ Try build successful - checks-actions
Build commit: 94bf4d541167db3e4c9bf41073fce29fa2e5d3ae (94bf4d541167db3e4c9bf41073fce29fa2e5d3ae)

[rust-timer]

Queued 94bf4d541167db3e4c9bf41073fce29fa2e5d3ae with parent 6cdd42f, future comparison URL.

[rust-timer]

Finished benchmarking commit (94bf4d541167db3e4c9bf41073fce29fa2e5d3ae): comparison url.

Summary: This change led to moderate relevant improvements 🎉 in compiler performance.

• Moderate improvement in instruction counts (up to -0.7% on incr-patched: println builds of coercions)

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.

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

[petrochenkov]

@cjgillot
Could you set the S-waiting-on-review label once this is ready?
I see that you are updating the lowering related PRs from time to time, but I'm not sure whether they are finished or not, so I didn't take any action.

[cjgillot]

With the latest perfect results, I believe this one is ready.

[petrochenkov]

@bors r+

[bors]

📌 Commit d60bbde has been approved by petrochenkov

[bors]

⌛ Testing commit d60bbde with merge 697118d...

[bors]

☀️ Test successful - checks-actions
Approved by: petrochenkov
Pushing 697118d to master...

[rust-timer]

Finished benchmarking commit (697118d): comparison url.

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

• Moderate improvement in instruction counts (up to -0.9% on incr-full builds of coercions)
• Small regression in instruction counts (up to 0.5% on incr-unchanged builds of webrender-wrench)

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