Metadata decoding s

[jdonszelmann]

r? @ghost

[rustbot]

These commits modify compiler targets.
(See the Target Tier Policy.)

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[jdonszelmann]

@bors try @rust-timer queue

[jdonszelmann]

cc: @oli-obk this is what I was talking about. not yet clean, but wanted to see what perf looked like :3

[rust-bors]

💔 Test for 694a8a4 failed: CI. Failed jobs:

• try - dist-x86_64-linux (web logs, extended logs)

[jdonszelmann]

@bors try

[rust-bors]

☀️ Try build successful (CI)
Build commit: 7ac6e1b (7ac6e1b480efa4bd33f86547b8e73a2122f069d0, parent: 8a3a6bdb68b4d4c9ed922840808b02015741331e)

[rust-timer]

Finished benchmarking commit (7ac6e1b): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

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

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.2%	[-0.4%, -0.2%]	8
Improvements ✅ (secondary)	-0.4%	[-1.4%, -0.1%]	32
All ❌✅ (primary)	-0.2%	[-0.4%, -0.2%]	8

Max RSS (memory usage)

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

Cycles

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

Binary size

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

Bootstrap: 471.041s -> 471.157s (0.02%)
Artifact size: 386.90 MiB -> 386.90 MiB (0.00%)

[oli-obk]

The large workspace benchmark shows improvements in not just instructions, but also time on the write dep info query.

Everything else is a mixed bag on time, unsure why other queries are affected. There are minimal improvements for incremental loading across the board. I'm guessing I'm general the branch predictor just got this all correct.