Move fast path checks to `evaluate_goal_raw` by jdonszelmann · Pull Request #158249 · rust-lang/rust

jdonszelmann · 2026-06-22T13:38:31Z

No description provided.

jdonszelmann · 2026-06-22T13:44:06Z

This tests a bunch of changes together. I've done diffs locally suggesting ~5% speedup across these 7 commits. Moving fast path checks to evaluate_goal_raw ~2%, making it return stalled_on another 3% or so and using TyOrConstInferVar ~0.5%

@bors try @rust-timer queue

Move fast path checks to `evaluate_goal_raw`

rust-log-analyzer · 2026-06-22T14:25:20Z

The job pr-check-2 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

 Documenting rustc_type_ir v0.0.0 (/checkout/compiler/rustc_type_ir)
warning: unresolved link to `InferCtxt::ty_or_const_infer_var_changed`
   --> compiler/rustc_type_ir/src/solve/mod.rs:948:17
    |
948 | /// Helper for [InferCtxt::ty_or_const_infer_var_changed] (see comment on that), currently
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no item named `InferCtxt` in scope
    |
    = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

[RUSTC-TIMING] rustc_middle test:false 20.003
    Checking rustc_transmute v0.0.0 (/checkout/compiler/rustc_transmute)
[RUSTC-TIMING] rustc_transmute test:false 0.486
    Checking rustc_infer v0.0.0 (/checkout/compiler/rustc_infer)
error: `rustc_type_ir` (lib doc) generated 1 warning
error: warnings are denied by `build.warnings` configuration
warning: build failed, waiting for other jobs to finish...
[RUSTC-TIMING] rustc_infer test:false 2.683
Command `/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo doc --target x86_64-unknown-linux-gnu -Zbinary-dep-depinfo -j 4 -Zroot-dir=/checkout --locked --color=always --profile=release --features 'llvm rustc' --manifest-path /checkout/compiler/rustc/Cargo.toml -Zskip-rustdoc-fingerprint --no-deps -Zrustdoc-map -p rustc-main -p rustc_abi -p rustc_arena -p rustc_ast -p rustc_ast_ir -p rustc_ast_lowering -p rustc_ast_passes -p rustc_ast_pretty -p rustc_attr_parsing -p rustc_baked_icu_data -p rustc_borrowck -p rustc_builtin_macros -p rustc_codegen_llvm -p rustc_codegen_ssa -p rustc_const_eval -p rustc_data_structures -p rustc_driver -p rustc_driver_impl -p rustc_error_codes -p rustc_error_messages -p rustc_errors -p rustc_expand -p rustc_feature -p rustc_fs_util -p rustc_graphviz -p rustc_hashes -p rustc_hir -p rustc_hir_analysis -p rustc_hir_id -p rustc_hir_pretty -p rustc_hir_typeck -p rustc_incremental -p rustc_index -p rustc_index_macros -p rustc_infer -p rustc_interface -p rustc_lexer -p rustc_lint -p rustc_lint_defs -p rustc_llvm -p rustc_log -p rustc_macros -p rustc_metadata -p rustc_middle -p rustc_mir_build -p rustc_mir_dataflow -p rustc_mir_transform -p rustc_monomorphize -p rustc_next_trait_solver -p rustc_parse -p rustc_parse_format -p rustc_passes -p rustc_pattern_analysis -p rustc_privacy -p rustc_proc_macro -p rustc_public -p rustc_public_bridge -p rustc_query_impl -p rustc_resolve -p rustc_sanitizers -p rustc_serialize -p rustc_session -p rustc_span -p rustc_symbol_mangling -p rustc_target -p rustc_thread_pool -p rustc_trait_selection -p rustc_traits -p rustc_transmute -p rustc_ty_utils -p rustc_type_ir -p rustc_type_ir_macros -p rustc_windows_rc [workdir=/checkout]` failed with exit code 101
Created at: src/bootstrap/src/core/build_steps/doc.rs:930:25
Executed at: src/bootstrap/src/core/build_steps/doc.rs:991:26

--- BACKTRACE vvv
   0: <bootstrap::utils::exec::DeferredCommand>::finish_process
             at /checkout/src/bootstrap/src/utils/exec.rs:939:17
   1: <bootstrap::utils::exec::DeferredCommand>::wait_for_output::<&bootstrap::utils::exec::ExecutionContext>
             at /checkout/src/bootstrap/src/utils/exec.rs:831:21
   2: <bootstrap::utils::exec::ExecutionContext>::run
             at /checkout/src/bootstrap/src/utils/exec.rs:741:45
   3: <bootstrap::utils::exec::BootstrapCommand>::run::<&bootstrap::core::builder::Builder>
             at /checkout/src/bootstrap/src/utils/exec.rs:339:27
   4: <bootstrap::core::build_steps::doc::Rustc as bootstrap::core::builder::Step>::run
             at /checkout/src/bootstrap/src/core/build_steps/doc.rs:991:26
   5: <bootstrap::core::builder::Builder>::ensure::<bootstrap::core::build_steps::doc::Rustc>
             at /checkout/src/bootstrap/src/core/builder/mod.rs:1597:36
   6: <bootstrap::core::build_steps::doc::Rustc as bootstrap::core::builder::Step>::make_run
             at /checkout/src/bootstrap/src/core/build_steps/doc.rs:900:21
   7: <bootstrap::core::builder::StepDescription>::maybe_run
             at /checkout/src/bootstrap/src/core/builder/mod.rs:476:13
   8: bootstrap::core::builder::cli_paths::match_paths_to_steps_and_run
             at /checkout/src/bootstrap/src/core/builder/cli_paths.rs:232:18
   9: <bootstrap::core::builder::Builder>::run_step_descriptions
             at /checkout/src/bootstrap/src/core/builder/mod.rs:1140:9
  10: <bootstrap::core::builder::Builder>::execute_cli
             at /checkout/src/bootstrap/src/core/builder/mod.rs:1119:14
  11: <bootstrap::Build>::build
             at /checkout/src/bootstrap/src/lib.rs:803:25
  12: bootstrap::main
             at /checkout/src/bootstrap/src/bin/main.rs:130:11
  13: <fn() as core::ops::function::FnOnce<()>>::call_once
             at /rustc/0417c25868d6dfbd1c291dfeae950504faa6f790/library/core/src/ops/function.rs:250:5
  14: std::sys::backtrace::__rust_begin_short_backtrace::<fn(), ()>
             at /rustc/0417c25868d6dfbd1c291dfeae950504faa6f790/library/std/src/sys/backtrace.rs:166:18
  15: std::rt::lang_start::<()>::{closure#0}
             at /rustc/0417c25868d6dfbd1c291dfeae950504faa6f790/library/std/src/rt.rs:206:18
  16: <&dyn core::ops::function::Fn<(), Output = i32> + core::marker::Sync + core::panic::unwind_safe::RefUnwindSafe as core::ops::function::FnOnce<()>>::call_once
             at /rustc/0417c25868d6dfbd1c291dfeae950504faa6f790/library/core/src/ops/function.rs:287:21
  17: std::panicking::catch_unwind::do_call::<&dyn core::ops::function::Fn<(), Output = i32> + core::marker::Sync + core::panic::unwind_safe::RefUnwindSafe, i32>
             at /rustc/0417c25868d6dfbd1c291dfeae950504faa6f790/library/std/src/panicking.rs:581:40
  18: std::panicking::catch_unwind::<i32, &dyn core::ops::function::Fn<(), Output = i32> + core::marker::Sync + core::panic::unwind_safe::RefUnwindSafe>
             at /rustc/0417c25868d6dfbd1c291dfeae950504faa6f790/library/std/src/panicking.rs:544:19
  19: std::panic::catch_unwind::<&dyn core::ops::function::Fn<(), Output = i32> + core::marker::Sync + core::panic::unwind_safe::RefUnwindSafe, i32>
             at /rustc/0417c25868d6dfbd1c291dfeae950504faa6f790/library/std/src/panic.rs:359:14
  20: std::rt::lang_start_internal::{closure#0}
             at /rustc/0417c25868d6dfbd1c291dfeae950504faa6f790/library/std/src/rt.rs:175:24
  21: std::panicking::catch_unwind::do_call::<std::rt::lang_start_internal::{closure#0}, isize>
             at /rustc/0417c25868d6dfbd1c291dfeae950504faa6f790/library/std/src/panicking.rs:581:40
---
  28: __libc_start_main
  29: _start


Command has failed. Rerun with -v to see more details.
Bootstrap failed while executing `doc compiler --stage 1`
Build completed unsuccessfully in 0:00:45
  local time: Mon Jun 22 14:25:04 UTC 2026
  network time: Mon, 22 Jun 2026 14:25:04 GMT
##[error]Process completed with exit code 1.

rust-bors · 2026-06-22T16:02:47Z

☀️ Try build successful (CI)
Build commit: 3f4f44d (3f4f44d99c410d3aadeb2731ddd6c5446c89eb72)
Base parent: 9030e34 (9030e345fe92df1ccefd0a8cdf61a9a9a5b73cb0)

rust-timer · 2026-06-22T16:43:44Z

Finished benchmarking commit (3f4f44d): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@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)	1.1%	[0.1%, 3.7%]	18
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.9%	[-4.9%, -0.0%]	5
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 0.6%, secondary 1.6%)

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

	mean	range	count
Regressions ❌ (primary)	2.7%	[2.7%, 2.7%]	1
Regressions ❌ (secondary)	2.2%	[1.7%, 2.7%]	9
Improvements ✅ (primary)	-1.4%	[-1.4%, -1.4%]	1
Improvements ✅ (secondary)	-1.2%	[-1.2%, -1.1%]	2
All ❌✅ (primary)	0.6%	[-1.4%, 2.7%]	2

Cycles

Results (secondary 3.2%)

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)	4.1%	[2.1%, 6.2%]	6
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.3%	[-2.3%, -2.3%]	1
All ❌✅ (primary)	-	-	0

Binary size

Results (primary 0.0%, secondary 0.1%)

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

	mean	range	count
Regressions ❌ (primary)	0.0%	[0.0%, 0.0%]	4
Regressions ❌ (secondary)	0.1%	[0.0%, 0.1%]	20
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.0%	[0.0%, 0.0%]	4

Bootstrap: 503.321s -> 505.38s (0.41%)
Artifact size: 353.40 MiB -> 353.04 MiB (-0.10%)

lcnr · 2026-06-23T10:50:49Z

+    fn is_changed_var(&self, var: TyOrConstInferVar) -> bool {
+        match var {
+            TyOrConstInferVar::Ty(vid) => {
+                !self.try_resolve_ty_var(vid).is_err_and(|_| self.root_var(vid) == vid)


🤔 why are we accessing the infer var table twice here? do we also do so with the old solver?

View changes since the review

as in both try_resolve_ty_var and self.root_var needs to fetch the root_var

see #151380 for what we could do instead

jdonszelmann added 7 commits June 22, 2026 15:32

move overflow check

26ab71e

move fast path into evaluate_goal

cfdf1b0

remove fastpath from fullfilment loop

6d06741

experiment with better evaluate_goal_step

a081528

return stalled info from fast path

bde41df

move goal fast path into evaluate_goal_cold

dd81111

move TyOrConstInferVar to rustc_type_ir

5c7893c

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rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jun 22, 2026

rust-bors Bot pushed a commit that referenced this pull request Jun 22, 2026

Auto merge of #158249 - jdonszelmann:move-checks, r=<try>

3f4f44d

Move fast path checks to `evaluate_goal_raw`

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rustbot added perf-regression Performance regression. and removed S-waiting-on-perf Status: Waiting on a perf run to be completed. labels Jun 22, 2026

lcnr reviewed Jun 23, 2026

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Move fast path checks to `evaluate_goal_raw`#158249

Move fast path checks to `evaluate_goal_raw`#158249
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lcnr Jun 23, 2026 •

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rust-timer commented Jun 22, 2026

Overall result: ❌✅ regressions and improvements - please read:

Instruction count

Max RSS (memory usage)

Cycles

Binary size

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