dart2js cps: Speed up integrity checking some more.

pkg/compiler/lib/src/js_backend/codegen/task.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// Generate code using the cps-based IR pipeline.
 library code_generator_task;
 
 import 'glue.dart';
 import 'codegen.dart';
 import 'unsugar.dart';
@@ skipping 84 matching lines @@
         if (false) {
           reporter.log('Using SSA compiler for platform element $element');
           return fallbackCompiler.compile(work);
         }
 
         if (tracer != null) {
           tracer.traceCompilation(element.name, null);
         }
         cps.FunctionDefinition cpsFunction = compileToCpsIr(element);
         cpsFunction = optimizeCpsIr(cpsFunction);
+        cpsIntegrityChecker = null;
         tree_ir.FunctionDefinition treeFunction = compileToTreeIr(cpsFunction);
         treeFunction = optimizeTreeIr(treeFunction);
         return compileToJavaScript(work, treeFunction);
       } on CodegenBailout catch (e) {
         String message = "Unable to compile $element with the new compiler.\n"
             "  Reason: ${e.message}";
         reporter.internalError(element, message);
       }
     });
   }
@@ skipping 63 matching lines @@
         return node is cps.Variable && node.type != null
             ? '$s:${formatTypeMask(node.type)}'
             : s;
       }
       DEBUG_MODE = true;
       print(';;; ==== After $passName ====');
       print(new SExpressionStringifier(printType).visit(cpsFunction));
     }
   }
 
+  CheckCpsIntegrity cpsIntegrityChecker;
+
   bool checkCpsIntegrity(cps.FunctionDefinition node, String previousPass) {
     cpsOptimizationTask.measureSubtask('Check integrity', () {
-      new CheckCpsIntegrity().check(node, previousPass);
+      if (cpsIntegrityChecker == null) {

[sra1, 2015/10/15 23:06:52]

Is this worth it?

[asgerf, 2015/10/16 07:43:30]

It is necessary to ensure we get one instance per compiled method, and not one
instance per whole program or one per pass.

It would be cleaner to initialize it in the compile() method, but if we do it in
here, the class can be tree shaken and/or won't be parsed.

+        cpsIntegrityChecker = new CheckCpsIntegrity();
+      }
+      cpsIntegrityChecker.check(node, previousPass);
     });
     return true; // So this can be used from assert().
   }
 
   cps.FunctionDefinition optimizeCpsIr(cps.FunctionDefinition cpsFunction) {
     cpsOptimizationTask.measure(() {
       TypeMaskSystem typeSystem = new TypeMaskSystem(compiler);
 
       applyCpsPass(new RedundantJoinEliminator(), cpsFunction);
       applyCpsPass(new RedundantPhiEliminator(), cpsFunction);
@@ skipping 71 matching lines @@
         treeOptimizationTask]
       ..addAll(fallbackCompiler.tasks);
   }
 
   js.Node attachPosition(js.Node node, AstElement element) {
     return node.withSourceInformation(
         sourceInformationFactory.createBuilderForContext(element)
             .buildDeclaration(element));
   }
 }