Emit getelementptr inbounds nuw for pointer::add()

[nikic]

Lower pointer::add (via intrinsic::offset with unsigned offset) to getelementptr inbounds nuw on LLVM versions that support it. This lets LLVM make use of the pre-condition that the offset addition does not wrap in an unsigned sense. Together with inbounds, this also implies that the offset is non-negative.

Fixes #137217.

[rustbot]

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[nikic]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 511c91a with merge 934001d...

[lcnr]

r? @scottmcm

[bors]

☀️ Try build successful - checks-actions
Build commit: 934001d (934001ddafec5df9468c91504d935de13ea65aff)

[rust-timer]

Finished benchmarking commit (934001d): comparison URL.

Overall result: no relevant changes - 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 benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results (primary 1.0%, secondary 6.0%)

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%	[2.0%, 2.6%]	2
Regressions ❌ (secondary)	6.0%	[6.0%, 6.0%]	1
Improvements ✅ (primary)	-1.5%	[-1.5%, -1.5%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	1.0%	[-1.5%, 2.6%]	3

Cycles

Results (primary 3.4%)

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)	3.4%	[3.4%, 3.4%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.4%	[3.4%, 3.4%]	1

Binary size

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

Bootstrap: 773.598s -> 773.894s (0.04%)
Artifact size: 360.32 MiB -> 360.32 MiB (0.00%)

[nikic]

Okay, those results aren't very interesting... should probably use it in more places. In particular this doesn't even cover slice indexing.

[nikic]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 9e7b184 with merge fb26d83...

[bors]

☀️ Try build successful - checks-actions
Build commit: fb26d83 (fb26d83173e2e6c470d8693cc5a3f18e26d7829b)

[rust-timer]

Finished benchmarking commit (fb26d83): comparison URL.

Overall result: no relevant changes - 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 benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results (primary 1.2%)

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)	2.1%	[1.4%, 2.5%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.6%	[-1.6%, -1.6%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	1.2%	[-1.6%, 2.5%]	4

Cycles

Results (primary -4.0%)

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)	-4.0%	[-5.7%, -1.6%]	6
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-4.0%	[-5.7%, -1.6%]	6

Binary size

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

Bootstrap: 773.063s -> 772.561s (-0.06%)
Artifact size: 362.34 MiB -> 362.33 MiB (-0.00%)

[scottmcm]

Cycle wins look like noise, but that's ok. More optimization potential without measurable compile-time perf cost sounds good to me.

@bors r+

[bors]

📌 Commit 9e7b184 has been approved by scottmcm

It is now in the queue for this repository.

[bors]

⌛ Testing commit 9e7b184 with merge e0be1a0...

[bors]

☀️ Test successful - checks-actions
Approved by: scottmcm
Pushing e0be1a0 to master...

[rust-timer]

Finished benchmarking commit (e0be1a0): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

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

Max RSS (memory usage)

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

Cycles

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

Binary size

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

Bootstrap: 769.943s -> 770.178s (0.03%)
Artifact size: 359.62 MiB -> 359.64 MiB (0.00%)