Cache MIR preorder traversal.

[cjgillot]

r? @ghost

[cjgillot]

@bors2 try @rust-timer queue

[rust-bors]

⌛ Trying commit 3fd54d2 with merge 8557ddf…

To cancel the try build, run the command @bors2 try cancel.

[rust-bors]

☀️ Try build successful (CI)
Build commit: 8557ddf (8557ddf1ebd8148b2bccd92b5066340ceb5ce352, parent: 68ac5abb067806a88464ddbfbd3c7eec877b488d)

[rust-timer]

Finished benchmarking commit (8557ddf): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

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.

Next Steps: If you can justify the regressions found in this try perf run, please do so in sufficient writing along with @rustbot label: +perf-regression-triaged. If not, please fix the regressions and do another perf run. If its results are neutral or positive, the label will be automatically removed.

@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)	0.4%	[0.2%, 0.7%]	37
Regressions ❌ (secondary)	0.4%	[0.1%, 0.9%]	31
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.0%	[-1.0%, -1.0%]	1
All ❌✅ (primary)	0.4%	[0.2%, 0.7%]	37

Max RSS (memory usage)

Results (primary -0.4%, secondary -0.7%)

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

	mean	range	count
Regressions ❌ (primary)	1.3%	[1.3%, 1.3%]	1
Regressions ❌ (secondary)	1.0%	[0.8%, 1.2%]	2
Improvements ✅ (primary)	-1.2%	[-1.7%, -0.7%]	2
Improvements ✅ (secondary)	-1.9%	[-2.2%, -1.3%]	3
All ❌✅ (primary)	-0.4%	[-1.7%, 1.3%]	3

Cycles

Results (secondary -5.2%)

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)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-5.2%	[-5.2%, -5.2%]	1
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 757.272s -> 758.468s (0.16%)
Artifact size: 372.17 MiB -> 372.13 MiB (-0.01%)