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

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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.

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

Preserve caches in a call to shrink_to_fit A small follow up to #142542.

Preserve caches in a call to shrink_to_fit A small follow up to rust-lang/rust#142542.

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

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

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a2d9687

cjgillot mentioned this pull request Jun 16, 2025

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

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SparrowLii approved these changes Jun 17, 2025

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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

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workingjubilee mentioned this pull request Jun 17, 2025

Rollup of 10 pull requests #142614

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bors merged commit 725d829 into rust-lang:master Jun 17, 2025
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rustbot added this to the 1.89.0 milestone Jun 17, 2025

cjgillot deleted the invalidate-simplify-cfg branch June 17, 2025 22:41

tmiasko mentioned this pull request Jun 18, 2025

Preserve caches in a call to shrink_to_fit #142675

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bors added a commit that referenced this pull request Jun 18, 2025

Auto merge of #142675 - tmiasko:preserve-cache, r=<try>

727e41c

Preserve caches in a call to shrink_to_fit A small follow up to #142542.

bors added a commit that referenced this pull request Jun 22, 2025

Auto merge of #142675 - tmiasko:preserve-cache, r=oli-obk

9972ebf

Preserve caches in a call to shrink_to_fit A small follow up to #142542.

github-actions bot pushed a commit to rust-lang/rustc-dev-guide that referenced this pull request Jun 23, 2025

Auto merge of #142675 - tmiasko:preserve-cache, r=oli-obk

4fe31a4

Preserve caches in a call to shrink_to_fit A small follow up to rust-lang/rust#142542.

github-actions bot pushed a commit to Clownsw/miri that referenced this pull request Jun 23, 2025

Auto merge of #142675 - tmiasko:preserve-cache, r=oli-obk

a61c08c

Preserve caches in a call to shrink_to_fit A small follow up to rust-lang/rust#142542.

lnicola pushed a commit to lnicola/rust-analyzer that referenced this pull request Jun 23, 2025

Auto merge of #142675 - tmiasko:preserve-cache, r=oli-obk

89a89df

Preserve caches in a call to shrink_to_fit A small follow up to rust-lang/rust#142542.

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Overall result: ✅ improvements - no action needed

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