[panstromek]

I can't believe this passed the tests first try.

[panstromek]

@bors try @rust-timer queue

[rust-log-analyzer]

The job test-pr-check-2 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

    Checking rustc_codegen_gcc v0.1.0 (/checkout/compiler/rustc_codegen_gcc)
error[E0308]: mismatched types
  --> compiler/rustc_codegen_gcc/src/attributes.rs:39:13
   |
39 |         let Some(ref terminator) = block.terminator else { continue };
   |             ^^^^^^^^^^^^^^^^^^^^   ---------------- this expression has type `Terminator<'tcx>`
   |             |
   |             expected `Terminator<'_>`, found `Option<_>`
   |
   = note: expected struct `Terminator<'tcx>`

[rust-bors]

☀️ Try build successful (CI)
Build commit: aa85a99 (aa85a99bc1b575ac4a2335976cbc96285ceb0f60)
Base parent: ae36fe2 (ae36fe22c7e590df40ffd53ac25fea35597c3f3d)

[rust-timer]

Finished benchmarking commit (aa85a99): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@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
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.2%]	4
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (secondary 2.2%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.2%	[2.2%, 2.2%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Cycles

Results (primary -2.3%, secondary 3.6%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	6.5%	[4.5%, 8.5%]	2
Improvements ✅ (primary)	-2.3%	[-2.6%, -2.1%]	2
Improvements ✅ (secondary)	-2.4%	[-2.4%, -2.4%]	1
All ❌✅ (primary)	-2.3%	[-2.6%, -2.1%]	2

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 483.826s -> 484.513s (0.14%)
Artifact size: 406.63 MiB -> 406.69 MiB (0.01%)

[workingjubilee]

simplifies the code, so ship it I guess?

was this ever actually a None?

[panstromek]

was this ever actually a None?

Yes, it is None during MIR building and in some mir opts - most notably in SimplifyCfg. I think there's 1-2 other ones as well.

I want get rid of the Option, but this way of doing it is pretty awkward, I did it just to try it out. It replaces None with custom Terminator sentinel value (Goto: BasicBlock::MAX). This makes most of the MIR code less awkward but makes the parts that use the Option more awkward.

This might be a good awkwardness tradeoff, but it will make it more difficult to reason about and bugs surface later (when indexing into basic blocks). I'd rather refactor these places a bit to avoid the need for an option.

[workingjubilee]

Ahhh.

Yeaaaahhh.

[rust-bors]

☔ The latest upstream changes (presumably #165597) made this pull request unmergeable. Please resolve the merge conflicts by rebasing.