feed resolver_for_lowering instead of storing it in a field

[oli-obk]

r? @cjgillot

opening this as

• a discussion for no_hash + feedable queries. I think we'll want those, but I don't quite understand why they are rejected beyond a double check of the stable hashes for situations where the query is fed but also read from incremental caches.
• and a discussion on removing all untracked fields from TyCtxt and setting it up so that they are fed queries instead

[rustbot]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @cjgillot (or someone else) soon.

Please see the contribution instructions for more information.

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[oli-obk]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 8eaad0d80b335214431ae613c66b11ff12cb36ff with merge 9ab71a5530ee352a73aeea36f60a172ce1f332ea...

[bors]

☀️ Try build successful - checks-actions
Build commit: 9ab71a5530ee352a73aeea36f60a172ce1f332ea (9ab71a5530ee352a73aeea36f60a172ce1f332ea)

[rust-timer]

Finished benchmarking commit (9ab71a5530ee352a73aeea36f60a172ce1f332ea): 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
Improvements ✅ (secondary)	-0.3%	[-0.3%, -0.3%]	1
All ❌✅ (primary)	-	-	0

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)	-	-	0
Improvements ✅ (secondary)	-2.2%	[-3.5%, -1.1%]	6
All ❌✅ (primary)	-	-	0

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)	9.6%	[9.6%, 9.6%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.3%	[-1.8%, -0.9%]	10
Improvements ✅ (secondary)	-3.0%	[-4.2%, -1.4%]	14
All ❌✅ (primary)	-0.3%	[-1.8%, 9.6%]	11

[cjgillot]

The main reason I disallowed no_hash was because I hadn't found a use case.
This one is great! I have 2 suggestions, and r=me.

[oli-obk]

@bors r=cjgillot

[bors]

📌 Commit f693b78 has been approved by cjgillot

It is now in the queue for this repository.

[bors]

⌛ Testing commit f693b78 with merge ed61c13...

[bors]

☀️ Test successful - checks-actions
Approved by: cjgillot
Pushing ed61c13 to master...

[rust-timer]

Finished benchmarking commit (ed61c13): comparison URL.

Overall result: ❌ regressions - ACTION NEEDED

Next Steps: If you can justify the regressions found in this perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please open an issue or create a new PR that fixes the regressions, add a comment linking to the newly created issue or PR, and then add the perf-regression-triaged label to this PR.

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

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%]	2
Regressions ❌ (secondary)	0.5%	[0.1%, 0.8%]	15
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.3%	[-0.3%, -0.3%]	1
All ❌✅ (primary)	0.2%	[0.2%, 0.3%]	2

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)	0.1%	[0.1%, 0.1%]	1
Regressions ❌ (secondary)	7.7%	[7.7%, 7.7%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.2%	[-6.5%, -1.6%]	3
All ❌✅ (primary)	0.1%	[0.1%, 0.1%]	1

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
Improvements ✅ (secondary)	-2.0%	[-2.0%, -2.0%]	1
All ❌✅ (primary)	-	-	0

[oli-obk]

While the performance looks like it is not noise, looking at it with cachegrind yields only inliner noise:

110,101,744  ???:rustc_mir_dataflow::drop_flag_effects::on_all_children_bits::is_terminal_path
 67,503,324  ???:<rustc_infer::infer::combine::CombineFields>::instantiate
-54,068,248  ???:<rustc_infer::infer::sub::Sub as rustc_middle::ty::relate::TypeRelation>::tys
-14,745,244  ???:rustc_mir_dataflow::drop_flag_effects::on_all_children_bits::on_all_children_bits::<rustc_mir_dataflow::drop_flag_effects::drop_flag_effects_for_location<<rustc_mir_dataflow::impls::MaybeUninitializedPlaces as rustc_mir_dataflow::framework::GenKillAnalysis>::statement_effect<rustc_index::bit_set::ChunkedBitSet<rustc_mir_dataflow::move_paths::MovePathIndex>>::{closure
-13,892,472  ???:rustc_mir_dataflow::drop_flag_effects::on_all_children_bits::on_all_children_bits::<rustc_mir_dataflow::drop_flag_effects::drop_flag_effects_for_location<<rustc_mir_dataflow::impls::MaybeInitializedPlaces as rustc_mir_dataflow::framework::GenKillAnalysis>::statement_effect<rustc_index::bit_set::ChunkedBitSet<rustc_mir_dataflow::move_paths::MovePathIndex>>::{closure
 -6,814,818  ???:rustc_mir_dataflow::drop_flag_effects::on_all_children_bits::on_all_children_bits::<&mut rustc_mir_dataflow::drop_flag_effects::drop_flag_effects_for_location<<rustc_mir_dataflow::impls::MaybeUninitializedPlaces as rustc_mir_dataflow::framework::GenKillAnalysis>::statement_effect<rustc_index::bit_set::ChunkedBitSet<rustc_mir_dataflow::move_paths::MovePathIndex>>::{closure
 -6,418,962  ???:rustc_mir_dataflow::drop_flag_effects::on_all_children_bits::on_all_children_bits::<&mut rustc_mir_dataflow::drop_flag_effects::drop_flag_effects_for_location<<rustc_mir_dataflow::impls::MaybeInitializedPlaces as rustc_mir_dataflow::framework::GenKillAnalysis>::statement_effect<rustc_index::bit_set::ChunkedBitSet<rustc_mir_dataflow::move_paths::MovePathIndex>>::{closure
 -4,980,660  ???:rustc_mir_dataflow::drop_flag_effects::on_all_children_bits::on_all_children_bits::<rustc_mir_dataflow::drop_flag_effects::drop_flag_effects_for_location<<rustc_mir_transform::elaborate_drops::ElaborateDropsCtxt>::drop_flags_for_locs::{closure
 -2,752,512  ???:rustc_mir_dataflow::drop_flag_effects::on_all_children_bits::on_all_children_bits::<&mut rustc_mir_dataflow::drop_flag_effects::drop_flag_effects_for_location<<rustc_mir_transform::elaborate_drops::ElaborateDropsCtxt>::drop_flags_for_locs::{closure
 -1,965,767  ???:<rustc_trait_selection::traits::select::SelectionContext>::select
   -983,094  ???:<ena::unify::UnificationTable<ena::unify::backing_vec::InPlace<rustc_type_ir::TyVid, &mut alloc::vec::Vec<ena::unify::VarValue<rustc_type_ir::TyVid>>, &mut rustc_infer::infer::undo_log::InferCtxtUndoLogs>>>::uninlined_get_root_key
   -917,494  ???:<rustc_middle::mir::syntax::Rvalue>::ty::<rustc_middle::mir::Body>
   -917,490  ???:<rustc_const_eval::interpret::eval_context::InterpCx<rustc_const_eval::const_eval::machine::CompileTimeInterpreter>>::statement
   -851,932  ???:<rustc_middle::mir::BasicBlockData>::expand_statements::<<rustc_mir_transform::deaggregator::Deaggregator as rustc_middle::mir::MirPass>::run_pass::{closure
   -786,405  ???:<rustc_mir_dataflow::framework::engine::Engine<rustc_borrowck::dataflow::Borrows>>::iterate_to_fixpoint
    524,329  ???:<rustc_borrowck::type_check::TypeChecker>::typeck_mir
    524,304  ???:<rustc_borrowck::borrow_set::BorrowSet>::build
    524,280  ???:<core::iter::adapters::map::Map<core::ops::range::Range<usize>, <rustc_const_eval::interpret::validity::ValidityVisitor<rustc_const_eval::const_eval::machine::CompileTimeInterpreter> as rustc_const_eval::interpret::visitor::ValueVisitor<rustc_const_eval::const_eval::machine::CompileTimeInterpreter>>::walk_value::{closure
    262,152  ???:rustc_mir_transform::check_unsafety::unsafety_check_result
   -131,074  ???:<rustc_mir_build::build::Builder>::as_operand

[pnkfelix]

Visiting for weekly performance triage

• the original timer run said this had no problem
• (though to be fair, I don't know what changes occurred to the commit series between that timer run and what landed)
• oli-obj investigated and found cachegrind shows this to be artifacts from inlining decisions
• The impact on cycle-counts (rather than instruction counts) was well within noise tolerance levels.
• Therefore, marked as triaged.

@rustbot label: +perf-regression-triaged