Bounds-check with PtrMetadata instead of Len in MIR by scottmcm · Pull Request #133734 · rust-lang/rust (original) (raw)

Finished benchmarking commit (b57d93d): comparison URL.

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

Our benchmarks found a performance regression caused by this PR.
This might be an actual regression, but it can also be just noise.

Next Steps:

If the regression was expected or you think it can be justified,
please write a comment with sufficient written justification, and add
@rustbot label: +perf-regression-triaged to it, to mark the regression as triaged.
If you think that you know of a way to resolve the regression, try to create
a new PR with a fix for the regression.
If you do not understand the regression or you think that it is just noise,
you can ask the @rust-lang/wg-compiler-performance working group for help (members of this group
were already notified of this PR).

@rustbot label: +perf-regression
cc @rust-lang/wg-compiler-performance

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.3%	[0.2%, 0.3%]	2
Improvements ✅ (primary)	-1.4%	[-1.4%, -1.4%]	1
Improvements ✅ (secondary)	-0.6%	[-0.8%, -0.4%]	6
All ❌✅ (primary)	-1.4%	[-1.4%, -1.4%]	1

Max RSS (memory usage)

Results (primary 3.2%, secondary -0.1%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

mean	range	count
Regressions ❌ (primary)	6.0%	[4.9%, 6.6%]	3
Regressions ❌ (secondary)	1.8%	[1.5%, 2.2%]	2
Improvements ✅ (primary)	-5.1%	[-5.1%, -5.1%]	1
Improvements ✅ (secondary)	-3.9%	[-3.9%, -3.9%]	1
All ❌✅ (primary)	3.2%	[-5.1%, 6.6%]	4

Cycles

Results (primary -1.1%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.1%	[-1.1%, -1.1%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-1.1%	[-1.1%, -1.1%]	1

Binary size

Results (primary -0.0%, secondary 0.1%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

mean	range	count
Regressions ❌ (primary)	0.1%	[0.0%, 0.5%]	14
Regressions ❌ (secondary)	0.1%	[0.1%, 0.1%]	1
Improvements ✅ (primary)	-0.2%	[-1.0%, -0.0%]	12
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.0%	[-1.0%, 0.5%]	26

Bootstrap: 768.736s -> 772.313s (0.47%)
Artifact size: 333.17 MiB -> 333.13 MiB (-0.01%)