Avoid some redundant work in GVN

[cjgillot]

The first 2 commits are about reducing the perf effect.

Third commit avoids doing redundant work: is a local is SSA, it already has been simplified, and the resulting value is in self.locals. No need to call any code on it.

The last commit avoids removing some storage statements.

r? wg-mir-opt

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[cjgillot]

@bors try @rust-timer queue

[bors]

⌛ Trying commit abc3f62 with merge 13099a3...

[bors]

☀️ Try build successful - checks-actions
Build commit: 13099a3 (13099a3967124ca0416b78ee139e3fe856be6b4e)

[bors]

☀️ Try build successful - checks-actions
Build commit: 13099a3 (13099a3967124ca0416b78ee139e3fe856be6b4e)

[rust-timer]

Finished benchmarking commit (13099a3): comparison URL.

Overall result: ❌✅ regressions and improvements - 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.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@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)	0.8%	[0.7%, 0.8%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.5%	[-0.7%, -0.3%]	4
Improvements ✅ (secondary)	-0.4%	[-0.4%, -0.4%]	1
All ❌✅ (primary)	0.0%	[-0.7%, 0.8%]	7

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)	2.9%	[0.2%, 5.9%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-4.1%	[-7.6%, -0.5%]	3
Improvements ✅ (secondary)	-2.3%	[-2.3%, -2.3%]	1
All ❌✅ (primary)	-0.6%	[-7.6%, 5.9%]	6

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)	1.0%	[1.0%, 1.0%]	2
Regressions ❌ (secondary)	2.8%	[2.0%, 3.8%]	8
Improvements ✅ (primary)	-0.6%	[-0.7%, -0.5%]	2
Improvements ✅ (secondary)	-2.2%	[-2.2%, -2.1%]	2
All ❌✅ (primary)	0.2%	[-0.7%, 1.0%]	4

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%	[0.0%, 0.6%]	29
Regressions ❌ (secondary)	0.1%	[0.0%, 0.2%]	2
Improvements ✅ (primary)	-0.3%	[-0.6%, -0.0%]	7
Improvements ✅ (secondary)	-0.8%	[-1.1%, -0.6%]	6
All ❌✅ (primary)	0.1%	[-0.6%, 0.6%]	36

Bootstrap: 667.681s -> 669.659s (0.30%)
Artifact size: 311.77 MiB -> 311.76 MiB (-0.00%)

[cjgillot]

r? wg-mir-opt

[oli-obk]

@bors r+

[bors]

📌 Commit 7e39100 has been approved by oli-obk

It is now in the queue for this repository.

[bors]

⌛ Testing commit 7e39100 with merge 2b69aec...

[bors]

💔 Test failed - checks-actions

[rust-log-analyzer]

A job failed! Check out the build log: (web) (plain)

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

[cjgillot]

@bors retry Could not resolve host: github.com

[bors]

⌛ Testing commit 7e39100 with merge 14eda5b...

[rust-log-analyzer]

The job aarch64-gnu failed! Check out the build log: (web) (plain)

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

[RUSTC-TIMING] rustc_query_impl test:true 47.863
[RUSTC-TIMING] rustc_interface test:false 74.534
[RUSTC-TIMING] rustc_traits test:true 0.754
[RUSTC-TIMING] rustc_passes test:true 6.875
##[error]The runner has received a shutdown signal. This can happen when the runner service is stopped, or a manually started runner is canceled.
##[group]Clock drift check
  local time: Tue Jan 16 00:02:28 UTC 2024
  network time: Tue, 16 Jan 2024 00:02:28 GMT
##[endgroup]
##[endgroup]
Session terminated, killing shell...[RUSTC-TIMING] rustc_borrowck test:true 15.315
 ...killed.
##[error]The operation was canceled.

[bors]

💔 Test failed - checks-actions

[cjgillot]

Shutdown signal, no visible reason.
@bors retry

[bors]

⌛ Testing commit 7e39100 with merge f9c2421...

[bors]

☀️ Test successful - checks-actions
Approved by: oli-obk
Pushing f9c2421 to master...

[rust-timer]

Finished benchmarking commit (f9c2421): comparison URL.

Overall result: ❌✅ regressions and improvements - ACTION NEEDED

Next Steps: If you can justify the regressions found in this perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please open an issue or create a new PR that fixes the regressions, add a comment linking to the newly created issue or PR, and then add the perf-regression-triaged label to this PR.

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

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)	0.8%	[0.6%, 0.9%]	4
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.7%	[-1.1%, -0.5%]	4
Improvements ✅ (secondary)	-0.4%	[-0.4%, -0.4%]	1
All ❌✅ (primary)	0.0%	[-1.1%, 0.9%]	8

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)	1.1%	[0.2%, 2.0%]	2
Regressions ❌ (secondary)	3.0%	[3.0%, 3.0%]	1
Improvements ✅ (primary)	-3.2%	[-4.2%, -2.3%]	2
Improvements ✅ (secondary)	-3.0%	[-3.0%, -3.0%]	1
All ❌✅ (primary)	-1.1%	[-4.2%, 2.0%]	4

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)	2.3%	[2.3%, 2.3%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-7.3%	[-7.3%, -7.3%]	1
All ❌✅ (primary)	2.3%	[2.3%, 2.3%]	1

Binary size

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

Bootstrap: 667.744s -> 666.062s (-0.25%)
Artifact size: 308.24 MiB -> 308.24 MiB (0.00%)

[pnkfelix]

• primary regressions are regex-1.5.5 debug-full, opt-incr-patched:Job, incr-full, and exa opt-full.
• the exa regression looks like a blip. The regex ones were predicted during a try run for the PR. I assume they were deemed acceptable as they are offset improvements elsewhere (or dismissed as noise?)
• marking as triaged.

@rustbot label: +perf-regression-triaged