Use if SHARDS == 1 in a couple more places.

[nnethercote]

It's already used in get_shard_by_value, doesn't hurt to add it in a
couple of related functions for consistency.

r? @ghost

[nnethercote]

I got a miniscule win from this locally, let's see how CI looks.

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

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

[bors]

⌛ Trying commit 5563b36 with merge 1e3f3d2d4ce19371443dde82cdd1d32c9169766b...

[bors]

☀️ Try build successful - checks-actions
Build commit: 1e3f3d2d4ce19371443dde82cdd1d32c9169766b (1e3f3d2d4ce19371443dde82cdd1d32c9169766b)

[rust-timer]

Queued 1e3f3d2d4ce19371443dde82cdd1d32c9169766b with parent 73a7423, future comparison URL.

[Kobzol]

https://godbolt.org/z/cq9nMvz1q This change is maybe redudant, since the optimizer will see that bits % 1 has to equal zero?

[Mark-Simulacrum]

Cc #94084 - which drops sharding totally (at least for non parallel)

[rust-timer]

Finished benchmarking commit (1e3f3d2d4ce19371443dde82cdd1d32c9169766b): comparison url.

Summary: This benchmark run did not return any relevant results.

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

[nnethercote]

Cc #94084 - which drops sharding totally (at least for non parallel)

It drops sharding for query caches, but not for interning.

[nnethercote]

This didn't end up being interesting, and #94084 is a more comprehensive possibility.