Separate move path tracking between borrowck and drop elaboration.

[cjgillot]

The primary goal of this PR is to skip creating a MovePathIndex for path that do not need dropping in drop elaboration.

The 2 first commits are cleanups.

The next 2 commits displace move errors from move-path builder to borrowck. Move-path builder keeps the same logic, but does not carry error information any more.

The remaining commits allow to filter MovePathIndex creation according to types. This is used in drop elaboration, to avoid computing dataflow for paths that do not need dropping.

[cjgillot]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 9e7067b with merge 6e61e35...

[bors]

☀️ Try build successful - checks-actions
Build commit: 6e61e35 (6e61e35c7511f1da2c2379bae4b5d2c214093e77)

[rust-timer]

Finished benchmarking commit (6e61e35): comparison URL.

Overall result: ✅ improvements - no action needed

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 may lead to changes in compiler perf.

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

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.6%	[-1.4%, -0.3%]	61
Improvements ✅ (secondary)	-0.9%	[-1.6%, -0.2%]	32
All ❌✅ (primary)	-0.6%	[-1.4%, -0.3%]	61

Max RSS (memory usage)

Results

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)	5.1%	[5.1%, 5.1%]	1
Regressions ❌ (secondary)	0.7%	[0.7%, 0.8%]	4
Improvements ✅ (primary)	-3.6%	[-5.4%, -2.5%]	3
Improvements ✅ (secondary)	-1.4%	[-2.3%, -0.7%]	4
All ❌✅ (primary)	-1.4%	[-5.4%, 5.1%]	4

Cycles

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

Binary size

Results

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)	0.0%	[0.0%, 0.1%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.0%	[-0.0%, -0.0%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.0%	[-0.0%, 0.1%]	4

Bootstrap: 630.4s -> 631.994s (0.25%)
Artifact size: 317.38 MiB -> 317.23 MiB (-0.05%)

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[cjgillot]

r? compiler

[petrochenkov]

I'm not very familiar with this code, but I worked with move paths several years ago when implementing unions, and I need to get familiar with it again for my work, so I'll review anyway.

[petrochenkov]

r=me after addressing the remaining comments (#116300 (comment), #116300 (comment)) or confirming that they are not worth addressing.
@rustbot author

[petrochenkov]

@bors r+

[bors]

📌 Commit c8f33ec has been approved by petrochenkov

It is now in the queue for this repository.

[bors]

⌛ Testing commit c8f33ec with merge cd674d6...

[bors]

☀️ Test successful - checks-actions
Approved by: petrochenkov
Pushing cd674d6 to master...

[rust-timer]

Finished benchmarking commit (cd674d6): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.2%	[0.1%, 0.2%]	5
Regressions ❌ (secondary)	0.2%	[0.2%, 0.2%]	2
Improvements ✅ (primary)	-0.7%	[-3.6%, -0.2%]	77
Improvements ✅ (secondary)	-1.1%	[-1.8%, -0.4%]	30
All ❌✅ (primary)	-0.7%	[-3.6%, 0.2%]	82

Max RSS (memory usage)

Results

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)	1.9%	[0.0%, 2.8%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-3.5%	[-4.8%, -2.9%]	4
Improvements ✅ (secondary)	-1.5%	[-4.0%, -0.7%]	5
All ❌✅ (primary)	-1.2%	[-4.8%, 2.8%]	7

Cycles

Results

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)	1.3%	[1.3%, 1.3%]	1
Regressions ❌ (secondary)	2.2%	[1.7%, 3.1%]	6
Improvements ✅ (primary)	-0.9%	[-1.1%, -0.6%]	4
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.4%	[-1.1%, 1.3%]	5

Binary size

Results

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%	[0.1%, 0.2%]	7
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.1%	[-0.3%, -0.0%]	8
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.0%	[-0.3%, 0.2%]	15

Bootstrap: missing data
Artifact size: 304.34 MiB -> 304.35 MiB (0.00%)