Remove CombineFields

[compiler-errors]

This conflicts with #131263, but if this one lands first then perhaps #131263 could then go ahead and remove all the branching on solver in TypeRelating. We could perhaps then rename TypeRelating to OldSolverRelating or something, idk.

r? lcnr

[rustbot]

changes to the core type system

cc @compiler-errors, @lcnr

[bors]

☔ The latest upstream changes (presumably #131226) made this pull request unmergeable. Please resolve the merge conflicts.

[lcnr]

no 😁 i don't think that's true

[lcnr]

r=me after nit and CI

[compiler-errors]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 0c5d2f9 with merge 9580eab...

[bors]

☀️ Try build successful - checks-actions
Build commit: 9580eab (9580eab40f61c905070aee12b044e25b23c49317)

[rust-timer]

Finished benchmarking commit (9580eab): 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)	0.2%	[0.2%, 0.3%]	8
Regressions ❌ (secondary)	3.0%	[0.3%, 8.4%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.4%	[-0.4%, -0.4%]	1
All ❌✅ (primary)	0.2%	[0.2%, 0.3%]	8

Max RSS (memory usage)

Results (primary 2.6%, secondary 2.7%)

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)	2.6%	[2.6%, 2.6%]	1
Regressions ❌ (secondary)	2.7%	[2.7%, 2.7%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.6%	[2.6%, 2.6%]	1

Cycles

Results (secondary 4.9%)

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)	4.9%	[4.9%, 4.9%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 774.76s -> 774.311s (-0.06%)
Artifact size: 329.55 MiB -> 329.53 MiB (-0.00%)

[compiler-errors]

The only one that's really bad is the one that (probably?) actually stresses LUB. I'd say this is probably fine 🤷

but I guess @lcnr vibe check?

[lcnr]

yeah, I don't think the deep-vector regression is meaningful and this significantly simplifies a future cleanup, so

@bors r+ rollup=never

[bors]

📌 Commit 0c5d2f9 has been approved by lcnr

It is now in the queue for this repository.

[bors]

⌛ Testing commit 0c5d2f9 with merge 61e1920...

[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)

[bors]

💔 Test failed - checks-actions

[compiler-errors]

@bors retry

[bors]

⌛ Testing commit 0c5d2f9 with merge 3ae715c...

[bors]

☀️ Test successful - checks-actions
Approved by: lcnr
Pushing 3ae715c to master...

[rust-timer]

Finished benchmarking commit (3ae715c): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Our benchmarks found a performance regression caused by this PR.
This might be an actual regression, but it can also be just noise.

Next Steps:

• If the regression was expected or you think it can be justified,
  please write a comment with sufficient written justification, and add
  @rustbot label: +perf-regression-triaged to it, to mark the regression as triaged.
• If you think that you know of a way to resolve the regression, try to create
  a new PR with a fix for the regression.
• If you do not understand the regression or you think that it is just noise,
  you can ask the @rust-lang/wg-compiler-performance working group for help (members of this group
  were already notified of this PR).

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

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	0.2%	[0.2%, 0.2%]	3
Regressions ❌ (secondary)	0.3%	[0.2%, 0.3%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.2%]	1
All ❌✅ (primary)	0.2%	[0.2%, 0.2%]	3

Max RSS (memory usage)

Results (primary -0.7%)

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)	1.2%	[1.0%, 1.4%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.5%	[-3.7%, -1.3%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.7%	[-3.7%, 1.4%]	4

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: 775.495s -> 775.103s (-0.05%)
Artifact size: 329.59 MiB -> 329.57 MiB (-0.00%)

[rylev]

Regressions were determined as acceptable here.

@rustbot label: +perf-regression-triaged