[perf experiment] Disable LowerSliceLenCalls

[saethlin]

r? @ghost

[saethlin]

@bors try @rust-timer queue

[bors]

⌛ Trying commit dd4ea93 with merge 5259a5b09e0b666497f9cf065d44f7bb83321b9d...

[rust-log-analyzer]

The job x86_64-gnu-llvm-14 failed! Check out the build log: (web) (plain)

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

running 255 tests
................................................................................i.......  88/255
.........................................................i...........iii................ 176/255
................F.iii.iiiiiF........ii........i................................
failures:

---- [mir-opt] tests/mir-opt/lower_slice_len.rs stdout ----
---- [mir-opt] tests/mir-opt/lower_slice_len.rs stdout ----
thread '[mir-opt] tests/mir-opt/lower_slice_len.rs' panicked at 'the mir dump file for lower_slice_len.bound.LowerSliceLenCalls.before.mir does not exist (requested in /checkout/tests/mir-opt/lower_slice_len.rs)', src/tools/compiletest/src/runtest.rs:3652:17

---- [mir-opt] tests/mir-opt/lower_array_len.rs stdout ----
---- [mir-opt] tests/mir-opt/lower_array_len.rs stdout ----
24           _7 = &(*_2);                     // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
25           _6 = move _7 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
26           StorageDead(_7);                 // scope 0 at $DIR/lower_array_len.rs:+1:20: +1:21
- -         _5 = Len((*_6));                 // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
- +         _5 = const N;                    // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
-           goto -> bb1;                     // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
+           _5 = core::slice::<impl [u8]>::len(move _6) -> bb1; // scope 0 at $DIR/lower_array_len.rs:+1:16: +1:27
+                                            // mir::Constant
+                                            // + span: $DIR/lower_array_len.rs:7:22: 7:25
+                                            // + literal: Const { ty: for<'a> fn(&'a [u8]) -> usize {core::slice::<impl [u8]>::len}, val: Value(<ZST>) }
31   
Build completed unsuccessfully in 0:13:06
32       bb1: {


thread '[mir-opt] tests/mir-opt/lower_array_len.rs' panicked at 'Actual MIR output differs from expected MIR output /checkout/tests/mir-opt/lower_array_len.array_bound.NormalizeArrayLen.diff', src/tools/compiletest/src/runtest.rs:3639:21

failures:
    [mir-opt] tests/mir-opt/lower_slice_len.rs
    [mir-opt] tests/mir-opt/lower_array_len.rs

[bors]

☀️ Try build successful - checks-actions
Build commit: 5259a5b09e0b666497f9cf065d44f7bb83321b9d (5259a5b09e0b666497f9cf065d44f7bb83321b9d)

[rust-timer]

Finished benchmarking commit (5259a5b09e0b666497f9cf065d44f7bb83321b9d): 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)	1.2%	[0.3%, 3.1%]	15
Regressions ❌ (secondary)	2.2%	[0.2%, 4.6%]	11
Improvements ✅ (primary)	-0.7%	[-0.8%, -0.7%]	2
Improvements ✅ (secondary)	-0.4%	[-0.5%, -0.4%]	3
All ❌✅ (primary)	1.0%	[-0.8%, 3.1%]	17

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)	4.8%	[0.4%, 10.1%]	6
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.5%	[-2.5%, -2.5%]	1
All ❌✅ (primary)	4.8%	[0.4%, 10.1%]	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)	2.2%	[2.2%, 2.3%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.2%	[2.2%, 2.3%]	2

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)	0.6%	[0.0%, 1.3%]	68
Regressions ❌ (secondary)	10.0%	[0.2%, 48.7%]	20
Improvements ✅ (primary)	-0.5%	[-1.1%, -0.0%]	9
Improvements ✅ (secondary)	-0.3%	[-0.3%, -0.3%]	1
All ❌✅ (primary)	0.4%	[-1.1%, 1.3%]	77

Bootstrap: 642.768s -> 642.693s (-0.01%)

[workingjubilee]

I'm surprised this is considered "regressions and improvements" instead of "overall regression", considering in other cases, there can be a few improvements but leaving it still marked solidly as "regression", as with disabling CopyProp.