Update host compiler to LLVM 16

[nikic]

Update the host compiler for dist-x86_64-linux to LLVM 16. In particular, this pulls in llvm/llvm-project@1de305d, which is needed to update Rust's own LLVM (#107224).

[rustbot]

r? @Mark-Simulacrum

(rustbot has picked a reviewer for you, use r? to override)

[nikic]

@bors try @rust-timer queue

[bors]

⌛ Trying commit ac7651a73bcd81d3f08af5885319d990ac847876 with merge 64c5e2fe193d64f285526bd0125c1799c7d54601...

[bors]

💔 Test failed - checks-actions

[nikic]

Ah yes, another display of how much LLD values backwards compatibility. Looks like you can't even build LLVM 15 using LLD 16.

[nikic]

Uff, and of course you can't even easily work around this by adding -Wl,--undefined-version to LDFLAGS, because cmake will sanity-check the compiler early in the build, long before -fuse-ld=lld is added, so we end up passing --undefined-version to an old ld.bfd version, which does not support it.

I'm inclined to just roll this change into the main LLVM 16 upgrade, even though I would have preferred a separate performance evaluation for this.

[nikic]

Closing in favor of #107224.

[nikic]

@bors try @rust-timer queue

[bors]

⌛ Trying commit cbf1517 with merge 68f5536e18acf6022f362483c791ebbcac264894...

[bors]

☀️ Try build successful - checks-actions
Build commit: 68f5536e18acf6022f362483c791ebbcac264894 (68f5536e18acf6022f362483c791ebbcac264894)

[rust-timer]

Finished benchmarking commit (68f5536e18acf6022f362483c791ebbcac264894): 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)	-0.7%	[-1.0%, -0.3%]	34
Improvements ✅ (secondary)	-0.7%	[-1.0%, -0.5%]	12
All ❌✅ (primary)	-0.7%	[-1.0%, -0.3%]	34

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)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-3.2%	[-4.2%, -2.6%]	6
Improvements ✅ (secondary)	-2.4%	[-4.1%, -0.7%]	55
All ❌✅ (primary)	-3.2%	[-4.2%, -2.6%]	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)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.0%	[-1.2%, -0.7%]	14
Improvements ✅ (secondary)	-0.9%	[-0.9%, -0.8%]	2
All ❌✅ (primary)	-1.0%	[-1.2%, -0.7%]	14

[nikic]

@rustbot ready

Thanks to llvm/llvm-project#61208, LLD 16 is capable of building LLVM 15 again, so we can land this separately after all.

[Mark-Simulacrum]

@bors r+ rollup=never

[bors]

📌 Commit cbf1517 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

[bors]

⌛ Testing commit cbf1517 with merge 2d0a7de...

[bors]

☀️ Test successful - checks-actions
Approved by: Mark-Simulacrum
Pushing 2d0a7de to master...

[rust-timer]

Finished benchmarking commit (2d0a7de): 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
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.7%	[-1.4%, -0.3%]	38
Improvements ✅ (secondary)	-0.9%	[-1.7%, -0.6%]	11
All ❌✅ (primary)	-0.7%	[-1.4%, -0.3%]	38

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)	1.4%	[1.4%, 1.4%]	1
Regressions ❌ (secondary)	2.0%	[2.0%, 2.1%]	2
Improvements ✅ (primary)	-1.0%	[-1.4%, -0.6%]	4
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.5%	[-1.4%, 1.4%]	5

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)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.8%	[-0.9%, -0.5%]	8
Improvements ✅ (secondary)	-1.2%	[-1.2%, -1.2%]	1
All ❌✅ (primary)	-0.8%	[-0.9%, -0.5%]	8