commit d78abd0a691c35d7f6ac98a15b81eb3aa718db06
author Alexander Markov <alexmarkov@google.com> Fri Sep 24 16:27:45 2021 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> Fri Sep 24 16:27:45 2021 +0000
tree 1a7201c2343b562aea3b8e9f34d17a53df771d0f
parent 22f1cee9d61eea059d49fbd261e8aea9132635dd

[vm/aot/tfa] Cache negative results of dispatch target lookup

When looking for a dispatch target, also cache not found selectors
to avoid repeated lookups.

Improves time of AOT compilation step 2 (TFA) on a large
Flutter application 189s -> 171s (-9.5%).

TEST=ci

Issue: https://github.com/dart-lang/sdk/issues/42442
Change-Id: I21686e1f40a09ef62abf010bfa3670615c108942
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/214342
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>

pkg/vm/lib/transformations/type_flow/analysis.dart

diff --git a/pkg/vm/lib/transformations/type_flow/analysis.dart b/pkg/vm/lib/transformations/type_flow/analysis.dart
index 989ad83..625616f 100644
--- a/pkg/vm/lib/transformations/type_flow/analysis.dart
+++ b/pkg/vm/lib/transformations/type_flow/analysis.dart
@@ -1008,11 +1008,12 @@
       target = typeFlowAnalysis.hierarchyCache.hierarchy.getDispatchTarget(
           classNode, selector.name,
           setter: selector.isSetter);
-      if (target != null) {
-        _dispatchTargets[selector] = target;
-      }
+      target ??= _DispatchableInvocation.kNoSuchMethodMarker;
+      _dispatchTargets[selector] = target;
     }
-    return target;
+    return identical(target, _DispatchableInvocation.kNoSuchMethodMarker)
+        ? null
+        : target;
   }
 
   String dump() => "$this {supers: $supertypes}";