commit 836ace6fcb3ecdef069b45ab4c545d758449b9ee
author Alexander Markov <alexmarkov@google.com> Fri May 03 23:34:28 2019 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> Fri May 03 23:34:28 2019 +0000
tree 1d2487ce63748b788cbad33af381ba6217c924ef
parent 1ef3818f79bff677d67e41ab1d93b1840baed4dd

[vm/bytecode] Avoid recalcualting class hierarchy for each dilp file

Compilation time in package-split mode with bytecode on a large app:
Before: 98 seconds
After: 37 seconds

Issue: b/131915611.
Change-Id: Ibc0ea460c9bb78d33441f91e977a914f97e8ce7f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/101325
Reviewed-by: Zach Anderson <zra@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>

pkg/vm/lib/bytecode/gen_bytecode.dart

diff --git a/pkg/vm/lib/bytecode/gen_bytecode.dart b/pkg/vm/lib/bytecode/gen_bytecode.dart
index f8ae346..21721a6 100644
--- a/pkg/vm/lib/bytecode/gen_bytecode.dart
+++ b/pkg/vm/lib/bytecode/gen_bytecode.dart
@@ -57,10 +57,11 @@
   Map<String, String> environmentDefines: const <String, String>{},
   ErrorReporter errorReporter,
   List<Library> libraries,
+  ClassHierarchy hierarchy,
 }) {
   final coreTypes = new CoreTypes(component);
   void ignoreAmbiguousSupertypes(Class cls, Supertype a, Supertype b) {}
-  final hierarchy = new ClassHierarchy(component,
+  hierarchy ??= new ClassHierarchy(component,
       onAmbiguousSupertypes: ignoreAmbiguousSupertypes);
   final typeEnvironment = new TypeEnvironment(coreTypes, hierarchy);
   final constantsBackend = new VmConstantsBackend(coreTypes);

pkg/vm/lib/kernel_front_end.dart

diff --git a/pkg/vm/lib/kernel_front_end.dart b/pkg/vm/lib/kernel_front_end.dart
index 452e2ca..703cfa8 100644
--- a/pkg/vm/lib/kernel_front_end.dart
+++ b/pkg/vm/lib/kernel_front_end.dart
@@ -678,6 +678,14 @@
     BytecodeSizeStatistics.reset();
   }
 
+  ClassHierarchy hierarchy;
+  if (genBytecode) {
+    // Calculating class hierarchy is an expensive operation.
+    // Calculate it once and reuse while generating bytecode for each package.
+    hierarchy =
+        new ClassHierarchy(component, onAmbiguousSupertypes: (cls, a, b) {});
+  }
+
   await runWithFrontEndCompilerContext(source, compilerOptions, component,
       () async {
     for (String package in packages) {
@@ -698,6 +706,7 @@
             .toList();
         generateBytecode(component,
             libraries: libraries,
+            hierarchy: hierarchy,
             emitSourcePositions: emitBytecodeSourcePositions,
             emitAnnotations: emitBytecodeAnnotations,
             useFutureBytecodeFormat: useFutureBytecodeFormat,