dart2js CPS: Small cleanup of the compilation pipeline.

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 66 matching lines @@
         // TODO(karlklose): remove this fallback when we do not need it for
         // testing anymore.
         if (false) {
           compiler.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);
-        tree_ir.FunctionDefinition treeFunction = compileToTreeIR(cpsFunction);
-        treeFunction = optimizeTreeIR(treeFunction);
+        cps.FunctionDefinition cpsFunction = compileToCpsIr(element);
+        cpsFunction = optimizeCpsIr(cpsFunction);
+        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}";
         compiler.internalError(element, message);
       }
     });
   }
 
   void giveUp(String reason) {
     throw new CodegenBailout(null, reason);
   }
 
   void traceGraph(String title, var irObject) {
     if (tracer != null) {
       tracer.traceGraph(title, irObject);
     }
   }
 
-  cps.FunctionDefinition compileToCpsIR(AstElement element) {
-    cps.FunctionDefinition cpsNode = irBuilderTask.buildNode(element);
-    if (cpsNode == null) {
+  void applyCpsPass(cps_opt.Pass pass, cps.FunctionDefinition cpsFunction) {
+    pass.rewrite(cpsFunction);
+    traceGraph(pass.passName, cpsFunction);
+    dumpTypedIr(pass.passName, cpsFunction);
+    assert(checkCpsIntegrity(cpsFunction));
+  }
+
+  cps.FunctionDefinition compileToCpsIr(AstElement element) {
+    cps.FunctionDefinition cpsFunction = irBuilderTask.buildNode(element);
+    if (cpsFunction == null) {
       if (irBuilderTask.bailoutMessage == null) {
         giveUp('unable to build cps definition of $element');
       } else {
         giveUp(irBuilderTask.bailoutMessage);
       }
     }
-    traceGraph("IR Builder", cpsNode);
+    traceGraph('IR Builder', cpsFunction);
+    dumpTypedIr('IR Builder', cpsFunction);
     // Eliminating redundant phis before the unsugaring pass will make it
     // insert fewer getInterceptor calls.
-    new RedundantPhiEliminator().rewrite(cpsNode);
-    traceGraph("Redundant phi elimination", cpsNode);
-    new UnsugarVisitor(glue).rewrite(cpsNode);
-    traceGraph("Unsugaring", cpsNode);
-    return cpsNode;
+    applyCpsPass(new RedundantPhiEliminator(), cpsFunction);
+    applyCpsPass(new UnsugarVisitor(glue), cpsFunction);
+    return cpsFunction;
   }
 
   static const Pattern PRINT_TYPED_IR_FILTER = null;
 
   String formatTypeMask(TypeMask type) {
     if (type is UnionTypeMask) {
       return '[${type.disjointMasks.map(formatTypeMask).join(', ')}]';
     } else if (type is FlatTypeMask) {
       if (type.isEmpty) {
         return "null";
       }
       String suffix = (type.isExact ? "" : "+") + (type.isNullable ? "?" : "!");
       return '${type.base.name}$suffix';
     } else if (type is ForwardingTypeMask) {
       return formatTypeMask(type.forwardTo);
     }
     throw 'unsupported: $type';
   }
 
-  void dumpTypedIR(cps.FunctionDefinition cpsNode,
-                   TypePropagator typePropagator) {
+  void dumpTypedIr(String passName, cps.FunctionDefinition cpsFunction) {
     if (PRINT_TYPED_IR_FILTER != null &&
-        PRINT_TYPED_IR_FILTER.matchAsPrefix(cpsNode.element.name) != null) {
+        PRINT_TYPED_IR_FILTER.matchAsPrefix(cpsFunction.element.name) != null) {
       String printType(nodeOrRef, String s) {
         cps.Node node = nodeOrRef is cps.Reference
             ? nodeOrRef.definition
             : nodeOrRef;
         return node is cps.Variable && node.type != null
             ? '$s:${formatTypeMask(node.type)}'
             : s;
       }
       DEBUG_MODE = true;
-      print(new SExpressionStringifier(printType).visit(cpsNode));
+      print(';;; ==== After $passName ====');
+      print(new SExpressionStringifier(printType).visit(cpsFunction));
     }
   }
 
   static bool checkCpsIntegrity(cps.FunctionDefinition node) {
     new CheckCpsIntegrity().check(node);
     return true; // So this can be used from assert().
   }
 
-  cps.FunctionDefinition optimizeCpsIR(cps.FunctionDefinition cpsNode) {
-    // Transformations on the CPS IR.
-    void applyCpsPass(cps_opt.Pass pass) {
-      pass.rewrite(cpsNode);
-      traceGraph(pass.passName, cpsNode);
-      assert(checkCpsIntegrity(cpsNode));
-    }
-
+  cps.FunctionDefinition optimizeCpsIr(cps.FunctionDefinition cpsFunction) {
     TypeMaskSystem typeSystem = new TypeMaskSystem(compiler);
 
-    applyCpsPass(new RedundantJoinEliminator());
-    applyCpsPass(new RedundantPhiEliminator());
-    applyCpsPass(new InsertRefinements(typeSystem));
-    TypePropagator typePropagator =
-        new TypePropagator(compiler, typeSystem, this);
-    applyCpsPass(typePropagator);
-    dumpTypedIR(cpsNode, typePropagator);
-    applyCpsPass(new RemoveRefinements());
-    applyCpsPass(new ShrinkingReducer());
-    applyCpsPass(new ScalarReplacer(compiler));
-    applyCpsPass(new MutableVariableEliminator());
-    applyCpsPass(new RedundantJoinEliminator());
-    applyCpsPass(new RedundantPhiEliminator());
-    applyCpsPass(new ShrinkingReducer());
-    applyCpsPass(new LoopInvariantCodeMotion());
-    applyCpsPass(new ShareInterceptors());
-    applyCpsPass(new ShrinkingReducer());
+    applyCpsPass(new RedundantJoinEliminator(), cpsFunction);
+    applyCpsPass(new RedundantPhiEliminator(), cpsFunction);
+    applyCpsPass(new InsertRefinements(typeSystem), cpsFunction);
+    applyCpsPass(new TypePropagator(compiler, typeSystem, this), cpsFunction);
+    applyCpsPass(new RemoveRefinements(), cpsFunction);
+    applyCpsPass(new ShrinkingReducer(), cpsFunction);
+    applyCpsPass(new ScalarReplacer(compiler), cpsFunction);
+    applyCpsPass(new MutableVariableEliminator(), cpsFunction);
+    applyCpsPass(new RedundantJoinEliminator(), cpsFunction);
+    applyCpsPass(new RedundantPhiEliminator(), cpsFunction);
+    applyCpsPass(new ShrinkingReducer(), cpsFunction);
+    applyCpsPass(new LoopInvariantCodeMotion(), cpsFunction);
+    applyCpsPass(new ShareInterceptors(), cpsFunction);
+    applyCpsPass(new ShrinkingReducer(), cpsFunction);
 
-    return cpsNode;
+    return cpsFunction;
   }
 
-  tree_ir.FunctionDefinition compileToTreeIR(cps.FunctionDefinition cpsNode) {
+  tree_ir.FunctionDefinition compileToTreeIr(cps.FunctionDefinition cpsNode) {
     tree_builder.Builder builder = new tree_builder.Builder(
         compiler.internalError);
     tree_ir.FunctionDefinition treeNode = builder.buildFunction(cpsNode);
     assert(treeNode != null);
     traceGraph('Tree builder', treeNode);
     assert(checkTreeIntegrity(treeNode));
     return treeNode;
   }
 
   static bool checkTreeIntegrity(tree_ir.FunctionDefinition node) {
     new CheckTreeIntegrity().check(node);
     return true; // So this can be used from assert().
   }
 
-  tree_ir.FunctionDefinition optimizeTreeIR(tree_ir.FunctionDefinition node) {
+  tree_ir.FunctionDefinition optimizeTreeIr(tree_ir.FunctionDefinition node) {
     void applyTreePass(tree_opt.Pass pass) {
       pass.rewrite(node);
       traceGraph(pass.passName, node);
       assert(checkTreeIntegrity(node));
     }
 
     applyTreePass(new StatementRewriter());
     applyTreePass(new VariableMerger());
     applyTreePass(new LoopRewriter());
     applyTreePass(new LogicalRewriter());
@@ skipping 18 matching lines @@
     // TODO(sigurdm): Make a better list of tasks.
     return <CompilerTask>[irBuilderTask]..addAll(fallbackCompiler.tasks);
   }
 
   js.Node attachPosition(js.Node node, AstElement element) {
     return node.withSourceInformation(
         sourceInformationFactory.createBuilderForContext(element)
             .buildDeclaration(element));
   }
 }