Manually invalidate caches in SimplifyCfg. #142542

cjgillot · 2025-06-15T15:32:48Z

The current SimplifyCfg pass unconditionally invalidates CFG caches. This is unfortunate if there are no modifications that require this invalidation.

rustbot · 2025-06-15T15:32:52Z

r? @SparrowLii

rustbot has assigned @SparrowLii.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

rustbot · 2025-06-15T15:32:53Z

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

cjgillot · 2025-06-15T15:32:56Z

@bors2 try @rust-timer queue

rust-bors · 2025-06-15T15:33:00Z

⌛ Trying commit a16b49b with merge cc03d9f…

To cancel the try build, run the command @bors2 try cancel.

Manually invalidate caches in SimplifyCfg. The current `SimplifyCfg` pass unconditionally invalidates CFG caches. This is unfortunate if there are no modifications that require this invalidation.

rust-bors · 2025-06-15T18:00:24Z

☀️ Try build successful (CI)
Build commit: cc03d9f (cc03d9fc4d0bea33e36b94f73ea9bce0685b0abb, parent: 75e7cf5f85aad82331a38deff24845b63eaf30f3)

compiler-errors · 2025-06-15T22:50:14Z

compiler/rustc_mir_transform/src/simplify.rs

@@ -121,19 +123,23 @@ impl<'a, 'tcx> CfgSimplifier<'a, 'tcx> {
        // Preserve `SwitchInt` reads on built and analysis MIR, or if `-Zmir-preserve-ub`.
        let preserve_switch_reads = matches!(body.phase, MirPhase::Built | MirPhase::Analysis(_))
            || tcx.sess.opts.unstable_opts.mir_preserve_ub;
-        let basic_blocks = body.basic_blocks_mut();
+        let basic_blocks = body.basic_blocks.as_mut_preserves_cfg();


Could use a comment explaining why this is okay

compiler-errors · 2025-06-15T22:50:54Z

compiler/rustc_mir_transform/src/simplify.rs

@@ -74,7 +74,9 @@ impl SimplifyCfg {
 }

 pub(super) fn simplify_cfg<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-    CfgSimplifier::new(tcx, body).simplify();
+    if CfgSimplifier::new(tcx, body).simplify() {


Coudl use a comment (even if it's reundant, b/c it's important).

rust-timer · 2025-06-15T23:07:12Z

Finished benchmarking commit (cc03d9f): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

@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)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.2%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (secondary -2.5%)

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)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.5%	[-2.5%, -2.5%]	1
All ❌✅ (primary)	-	-	0

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: 756.494s -> 755.634s (-0.11%)
Artifact size: 372.15 MiB -> 372.16 MiB (0.00%)

SparrowLii · 2025-06-17T01:25:20Z

@bors r+ rollup

bors · 2025-06-17T01:25:23Z

📌 Commit a2d9687 has been approved by SparrowLii

It is now in the queue for this repository.

Rollup of 13 pull requests Successful merges: - #138538 (Make performance description of String::{insert,insert_str,remove} more precise) - #141946 (std: refactor explanation of `NonNull`) - #142216 (Miscellaneous RefCell cleanups) - #142542 (Manually invalidate caches in SimplifyCfg.) - #142563 (Refine run-make test ignores due to unpredictable `i686-pc-windows-gnu` unwind mechanism) - #142570 (Reject union default field values) - #142584 (Handle same-crate macro for borrowck semicolon suggestion) - #142585 (Update books) - #142586 (Fold unnecessary `visit_struct_field_def` in AstValidator) - #142587 (Make sure to propagate result from `visit_expr_fields`) - #142595 (Revert overeager warning for misuse of `--print native-static-libs`) - #142598 (Set elf e_flags on ppc64 targets according to abi) - #142601 (Add a comment to `FORMAT_VERSION`.) r? `@ghost` `@rustbot` modify labels: rollup  [Create a similar rollup](https://bors.rust-lang.org/queue/rust?prs=138538,141946,142216,142542,142563,142570,142584,142585,142586,142587,142595,142598,142601)  try-job: dist-apple-various

…r=SparrowLii Manually invalidate caches in SimplifyCfg. The current `SimplifyCfg` pass unconditionally invalidates CFG caches. This is unfortunate if there are no modifications that require this invalidation.

Rollup of 10 pull requests Successful merges: - #138538 (Make performance description of String::{insert,insert_str,remove} more precise) - #141946 (std: refactor explanation of `NonNull`) - #142216 (Miscellaneous RefCell cleanups) - #142371 (avoid `&mut P<T>` in `visit_expr` etc methods) - #142377 (Try unremapping compiler sources) - #142517 (Windows: Use anonymous pipes in Command) - #142542 (Manually invalidate caches in SimplifyCfg.) - #142563 (Refine run-make test ignores due to unpredictable `i686-pc-windows-gnu` unwind mechanism) - #142570 (Reject union default field values) - #142584 (Handle same-crate macro for borrowck semicolon suggestion) r? `@ghost` `@rustbot` modify labels: rollup

Rollup of 10 pull requests Successful merges: - #138538 (Make performance description of String::{insert,insert_str,remove} more precise) - #141946 (std: refactor explanation of `NonNull`) - #142216 (Miscellaneous RefCell cleanups) - #142371 (avoid `&mut P<T>` in `visit_expr` etc methods) - #142377 (Try unremapping compiler sources) - #142517 (Windows: Use anonymous pipes in Command) - #142542 (Manually invalidate caches in SimplifyCfg.) - #142563 (Refine run-make test ignores due to unpredictable `i686-pc-windows-gnu` unwind mechanism) - #142570 (Reject union default field values) - #142584 (Handle same-crate macro for borrowck semicolon suggestion) r? `@ghost` `@rustbot` modify labels: rollup  [Create a similar rollup](https://bors.rust-lang.org/queue/rust?prs=138538,141946,142216,142371,142377,142517,142542,142563,142570,142584)  try-job: dist-aarch64-apple

Rollup of 13 pull requests Successful merges: - #138538 (Make performance description of String::{insert,insert_str,remove} more precise) - #141946 (std: refactor explanation of `NonNull`) - #142216 (Miscellaneous RefCell cleanups) - #142542 (Manually invalidate caches in SimplifyCfg.) - #142563 (Refine run-make test ignores due to unpredictable `i686-pc-windows-gnu` unwind mechanism) - #142570 (Reject union default field values) - #142584 (Handle same-crate macro for borrowck semicolon suggestion) - #142585 (Update books) - #142586 (Fold unnecessary `visit_struct_field_def` in AstValidator) - #142587 (Make sure to propagate result from `visit_expr_fields`) - #142595 (Revert overeager warning for misuse of `--print native-static-libs`) - #142598 (Set elf e_flags on ppc64 targets according to abi) - #142601 (Add a comment to `FORMAT_VERSION`.) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of #142542 - cjgillot:invalidate-simplify-cfg, r=SparrowLii Manually invalidate caches in SimplifyCfg. The current `SimplifyCfg` pass unconditionally invalidates CFG caches. This is unfortunate if there are no modifications that require this invalidation.

Manually invalidate caches in SimplifyCfg.

a16b49b

rustbot assigned SparrowLii Jun 15, 2025

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Jun 15, 2025

This comment has been minimized.

Sign in to view

rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jun 15, 2025

This comment has been minimized.

Sign in to view

compiler-errors reviewed Jun 15, 2025

View reviewed changes

rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jun 15, 2025

Add comment.

a2d9687

cjgillot mentioned this pull request Jun 16, 2025

Pre-compute MIR CFG caches for borrowck and other analyses #142540

Open

SparrowLii approved these changes Jun 17, 2025

View reviewed changes

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jun 17, 2025

workingjubilee mentioned this pull request Jun 17, 2025

Rollup of 13 pull requests #142613

Merged

workingjubilee mentioned this pull request Jun 17, 2025

Rollup of 10 pull requests #142614

Open

bors merged commit 725d829 into rust-lang:master Jun 17, 2025
10 checks passed

rustbot added this to the 1.89.0 milestone Jun 17, 2025

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Manually invalidate caches in SimplifyCfg. #142542

Manually invalidate caches in SimplifyCfg. #142542

Uh oh!

cjgillot commented Jun 15, 2025

Uh oh!

rustbot commented Jun 15, 2025

Uh oh!

rustbot commented Jun 15, 2025

Uh oh!

cjgillot commented Jun 15, 2025

Uh oh!

This comment has been minimized.

rust-bors bot commented Jun 15, 2025

Uh oh!

rust-bors bot commented Jun 15, 2025

Uh oh!

This comment has been minimized.

compiler-errors Jun 15, 2025

Uh oh!

compiler-errors Jun 15, 2025

Uh oh!

rust-timer commented Jun 15, 2025

Uh oh!

SparrowLii commented Jun 17, 2025

Uh oh!

bors commented Jun 17, 2025

Uh oh!

Uh oh!

Uh oh!

Manually invalidate caches in SimplifyCfg. #142542

Manually invalidate caches in SimplifyCfg. #142542

Uh oh!

Conversation

cjgillot commented Jun 15, 2025

Uh oh!

rustbot commented Jun 15, 2025

Uh oh!

rustbot commented Jun 15, 2025

Uh oh!

cjgillot commented Jun 15, 2025

Uh oh!

This comment has been minimized.

rust-bors bot commented Jun 15, 2025

Uh oh!

rust-bors bot commented Jun 15, 2025

Uh oh!

This comment has been minimized.

compiler-errors Jun 15, 2025

Choose a reason for hiding this comment

Uh oh!

compiler-errors Jun 15, 2025

Choose a reason for hiding this comment

Uh oh!

rust-timer commented Jun 15, 2025

Overall result: ✅ improvements - no action needed

Instruction count

Max RSS (memory usage)

Cycles

Binary size

Uh oh!

SparrowLii commented Jun 17, 2025

Uh oh!

bors commented Jun 17, 2025

Uh oh!

Uh oh!

Uh oh!