Apply RemoveNoopLandingPads post-monomorphization

[Mark-Simulacrum]

On cargo this cuts ~5% of the LLVM IR lines we generate (measured with -Cno-prepopulate-passes).

[Mark-Simulacrum]

@bors2 try @rust-timer queue

[rust-bors]

⌛ Trying commit e0423d5 with merge fb9de75…

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

[rust-timer]

Finished benchmarking commit (e3a4b05): comparison URL.

Overall result: ✅ improvements - no action needed

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.

@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%	[0.4%, 0.4%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.0%	[-4.6%, -0.2%]	22
Improvements ✅ (secondary)	-2.8%	[-18.0%, -0.8%]	17
All ❌✅ (primary)	-1.9%	[-4.6%, 0.4%]	23

Max RSS (memory usage)

Results (primary -2.6%, secondary -1.3%)

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)	-2.6%	[-3.8%, -1.2%]	6
Improvements ✅ (secondary)	-1.3%	[-2.8%, -0.5%]	3
All ❌✅ (primary)	-2.6%	[-3.8%, -1.2%]	6

Cycles

Results (primary -2.4%, secondary -2.8%)

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

	mean	range	count
Regressions ❌ (primary)	1.1%	[1.1%, 1.1%]	1
Regressions ❌ (secondary)	3.2%	[0.8%, 7.1%]	4
Improvements ✅ (primary)	-2.6%	[-4.3%, -1.2%]	22
Improvements ✅ (secondary)	-5.0%	[-20.0%, -0.5%]	11
All ❌✅ (primary)	-2.4%	[-4.3%, 1.1%]	23

Binary size

Results (primary -0.6%, secondary -0.8%)

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)	-0.6%	[-1.4%, -0.0%]	66
Improvements ✅ (secondary)	-0.8%	[-3.6%, -0.0%]	30
All ❌✅ (primary)	-0.6%	[-1.4%, -0.0%]	66

Bootstrap: 461.485s -> 461.37s (-0.02%)
Artifact size: 372.20 MiB -> 371.78 MiB (-0.11%)

[oli-obk]

@bors r+

[bors]

📌 Commit 676eed3 has been approved by oli-obk

It is now in the queue for this repository.

[cjgillot]

Is there an opportunity to reuse code from RemoveNoopLandingPads MIR pass?

[RalfJung]

Given that comments and variable names don't line up, seems better to
@bors r-

[Mark-Simulacrum]

@bors2 try @rust-timer queue

This is essentially a re-write with @cjgillot's excellent suggestion to reuse the analysis in RemoveNoopLandingPads. Also adjusted some of the naming per @RalfJung's comments -- I'm not perfectly happy with the names, some of this is sort of quasi-true (e.g., reachable is only accurate if you apply the right filters while you traverse the MIR, since we currently can't edit it in-place).

[rust-timer]

Finished benchmarking commit (d12ed3f): comparison URL.

Overall result: ✅ improvements - no action needed

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.

@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
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.1%	[-5.1%, -0.2%]	28
Improvements ✅ (secondary)	-3.2%	[-18.1%, -0.4%]	19
All ❌✅ (primary)	-2.1%	[-5.1%, -0.2%]	28

Max RSS (memory usage)

Results (primary -2.0%, secondary 2.4%)

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

	mean	range	count
Regressions ❌ (primary)	3.4%	[2.6%, 4.2%]	2
Regressions ❌ (secondary)	2.4%	[0.7%, 4.1%]	2
Improvements ✅ (primary)	-4.2%	[-5.6%, -3.4%]	5
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.0%	[-5.6%, 4.2%]	7

Cycles

Results (primary -2.6%, secondary -4.8%)

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

	mean	range	count
Regressions ❌ (primary)	3.0%	[2.1%, 3.8%]	2
Regressions ❌ (secondary)	0.7%	[0.7%, 0.7%]	1
Improvements ✅ (primary)	-3.2%	[-5.6%, -1.5%]	18
Improvements ✅ (secondary)	-5.2%	[-19.9%, -2.0%]	14
All ❌✅ (primary)	-2.6%	[-5.6%, 3.8%]	20

Binary size

Results (primary -0.7%, secondary -1.1%)

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)	-0.7%	[-1.4%, -0.0%]	67
Improvements ✅ (secondary)	-1.1%	[-3.7%, -0.0%]	30
All ❌✅ (primary)	-0.7%	[-1.4%, -0.0%]	67

Bootstrap: 461.735s -> 459.425s (-0.50%)
Artifact size: 372.23 MiB -> 372.22 MiB (-0.00%)

[Kobzol]

Awesome wins! I wonder why it only works for debug - is it some interaction with -Zshare-generics?