jdk8-mips64-public/nashorn: src/jdk/nashorn/internal/codegen/ApplySpecialization.java@03c06c337d9d (annotated)

src/jdk/nashorn/internal/codegen/ApplySpecialization.java@03c06c337d9d (annotated)

src/jdk/nashorn/internal/codegen/ApplySpecialization.java

Mon, 20 Oct 2014 12:06:36 +0200

author: attila
date: Mon, 20 Oct 2014 12:06:36 +0200
changeset 1064: 03c06c337d9d
parent 1028: d79265f2fa92
child 1086: d0b26e6f602c
permissions: -rw-r--r--

8059844: Implement optimistic splitter
Reviewed-by: hannesw, lagergren

 /*
  * Copyright (c) 2010, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package jdk.nashorn.internal.codegen;
 import static jdk.nashorn.internal.codegen.CompilerConstants.ARGUMENTS_VAR;
 import static jdk.nashorn.internal.codegen.CompilerConstants.EXPLODED_ARGUMENT_PREFIX;
 import java.lang.invoke.MethodType;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Deque;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import jdk.nashorn.internal.ir.AccessNode;
 import jdk.nashorn.internal.ir.CallNode;
 import jdk.nashorn.internal.ir.Expression;
 import jdk.nashorn.internal.ir.FunctionNode;
 import jdk.nashorn.internal.ir.FunctionNode.CompilationState;
 import jdk.nashorn.internal.ir.IdentNode;
 import jdk.nashorn.internal.ir.LexicalContext;
 import jdk.nashorn.internal.ir.Node;
 import jdk.nashorn.internal.ir.visitor.NodeVisitor;
 import jdk.nashorn.internal.objects.Global;
 import jdk.nashorn.internal.runtime.Context;
 import jdk.nashorn.internal.runtime.logging.DebugLogger;
 import jdk.nashorn.internal.runtime.logging.Loggable;
 import jdk.nashorn.internal.runtime.logging.Logger;
 import jdk.nashorn.internal.runtime.options.Options;
 /**
  * An optimization that attempts to turn applies into calls. This pattern
  * is very common for fake class instance creation, and apply
  * introduces expensive args collection and boxing
  *
  * <pre>
  * var Class = {
  *     create: function() {
  *         return function() { //vararg
  *             this.initialize.apply(this, arguments);
  *         }
  *     }
  * };
  *
  * Color = Class.create();
  *
  * Color.prototype = {
  *    red: 0, green: 0, blue: 0,
  *    initialize: function(r,g,b) {
  *        this.red = r;
  *        this.green = g;
  *        this.blue = b;
  *    }
  * }
  *
  * new Color(17, 47, 11);
  * </pre>
  */
 @Logger(name="apply2call")
 public final class ApplySpecialization extends NodeVisitor<LexicalContext> implements Loggable {
     private static final boolean USE_APPLY2CALL = Options.getBooleanProperty("nashorn.apply2call", true);
     private final DebugLogger log;
     private final Compiler compiler;
     private final Set<Integer> changed = new HashSet<>();
     private final Deque<List<IdentNode>> explodedArguments = new ArrayDeque<>();
     private static final String ARGUMENTS = ARGUMENTS_VAR.symbolName();
     /**
      * Apply specialization optimization. Try to explode arguments and call
      * applies as calls if they just pass on the "arguments" array and
      * "arguments" doesn't escape.
      *
      * @param compiler compiler
      */
     public ApplySpecialization(final Compiler compiler) {
         super(new LexicalContext());
         this.compiler = compiler;
         this.log = initLogger(compiler.getContext());
     }
     @Override
     public DebugLogger getLogger() {
         return log;
     }
     @Override
     public DebugLogger initLogger(final Context context) {
         return context.getLogger(this.getClass());
     }
     /**
      * Arguments may only be used as args to the apply. Everything else is disqualified
      * We cannot control arguments if they escape from the method and go into an unknown
      * scope, thus we are conservative and treat any access to arguments outside the
      * apply call as a case of "we cannot apply the optimization".
      *
      * @return true if arguments escape
      */
     private boolean argumentsEscape(final FunctionNode functionNode) {
         @SuppressWarnings("serial")
         final UnsupportedOperationException uoe = new UnsupportedOperationException() {
             @Override
             public synchronized Throwable fillInStackTrace() {
                 return null;
             }
         };
         final Set<Expression> argumentsFound = new HashSet<>();
         final Deque<Set<Expression>> stack = new ArrayDeque<>();
         //ensure that arguments is only passed as arg to apply
         try {
             functionNode.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) {
                 private boolean isCurrentArg(final Expression expr) {
                     return !stack.isEmpty() && stack.peek().contains(expr); //args to current apply call
                 }
                 private boolean isArguments(final Expression expr) {
                     if (expr instanceof IdentNode && ARGUMENTS.equals(((IdentNode)expr).getName())) {
                         argumentsFound.add(expr);
                         return true;
                     }
                     return false;
                 }
                 private boolean isParam(final String name) {
                     for (final IdentNode param : functionNode.getParameters()) {
                         if (param.getName().equals(name)) {
                             return true;
                         }
                     }
                     return false;
                 }
                 @Override
                 public Node leaveIdentNode(final IdentNode identNode) {
                     if (isParam(identNode.getName()) || isArguments(identNode) && !isCurrentArg(identNode)) {
                         throw uoe; //avoid filling in stack trace
                     }
                     return identNode;
                 }
                 @Override
                 public boolean enterCallNode(final CallNode callNode) {
                     final Set<Expression> callArgs = new HashSet<>();
                     if (isApply(callNode)) {
                         final List<Expression> argList = callNode.getArgs();
                         if (argList.size() != 2 || !isArguments(argList.get(argList.size() - 1))) {
                             throw new UnsupportedOperationException();
                         }
                         callArgs.addAll(callNode.getArgs());
                     }
                     stack.push(callArgs);
                     return true;
                 }
                 @Override
                 public Node leaveCallNode(final CallNode callNode) {
                     stack.pop();
                     return callNode;
                 }
             });
         } catch (final UnsupportedOperationException e) {
             if (!argumentsFound.isEmpty()) {
                 log.fine("'arguments' is used but escapes, or is reassigned in '" + functionNode.getName() + "'. Aborting");
             }
             return true; //bad
         }
         return false;
     }
     @Override
     public boolean enterCallNode(final CallNode callNode) {
         return !explodedArguments.isEmpty();
     }
     @Override
     public Node leaveCallNode(final CallNode callNode) {
         //apply needs to be a global symbol or we don't allow it
         final List<IdentNode> newParams = explodedArguments.peek();
         if (isApply(callNode)) {
             final List<Expression> newArgs = new ArrayList<>();
             for (final Expression arg : callNode.getArgs()) {
                 if (arg instanceof IdentNode && ARGUMENTS.equals(((IdentNode)arg).getName())) {
                     newArgs.addAll(newParams);
                 } else {
                     newArgs.add(arg);
                 }
             }
             changed.add(lc.getCurrentFunction().getId());
             final CallNode newCallNode = callNode.setArgs(newArgs).setIsApplyToCall();
             log.fine("Transformed ",
                     callNode,
                     " from apply to call => ",
                     newCallNode,
                     " in ",
                     DebugLogger.quote(lc.getCurrentFunction().getName()));
             return newCallNode;
         }
         return callNode;
     }
     private boolean pushExplodedArgs(final FunctionNode functionNode) {
         int start = 0;
         final MethodType actualCallSiteType = compiler.getCallSiteType(functionNode);
         if (actualCallSiteType == null) {
             return false;
         }
         assert actualCallSiteType.parameterType(actualCallSiteType.parameterCount() - 1) != Object[].class : "error vararg callsite passed to apply2call " + functionNode.getName() + " " + actualCallSiteType;
         final TypeMap ptm = compiler.getTypeMap();
         if (ptm.needsCallee()) {
             start++;
         }
         start++; //we always uses this
         final List<IdentNode> params    = functionNode.getParameters();
         final List<IdentNode> newParams = new ArrayList<>();
         final long to = Math.max(params.size(), actualCallSiteType.parameterCount() - start);
         for (int i = 0; i < to; i++) {
             if (i >= params.size()) {
                 newParams.add(new IdentNode(functionNode.getToken(), functionNode.getFinish(), EXPLODED_ARGUMENT_PREFIX.symbolName() + (i)));
             } else {
                 newParams.add(params.get(i));
             }
         }
         explodedArguments.push(newParams);
         return true;
     }
     @Override
     public boolean enterFunctionNode(final FunctionNode functionNode) {
         if (!USE_APPLY2CALL) {
             return false;
         }
         if (!Global.isBuiltinFunctionPrototypeApply()) {
             log.fine("Apply transform disabled: apply/call overridden");
             assert !Global.isBuiltinFunctionPrototypeCall() : "call and apply should have the same SwitchPoint";
             return false;
         }
         if (!compiler.isOnDemandCompilation()) {
             return false;
         }
         if (functionNode.hasEval()) {
             return false;
         }
         if (argumentsEscape(functionNode)) {
             return false;
         }
         return pushExplodedArgs(functionNode);
     }
     /**
      * Try to do the apply to call transformation
      * @return true if successful, false otherwise
      */
     @Override
     public Node leaveFunctionNode(final FunctionNode functionNode0) {
         FunctionNode newFunctionNode = functionNode0;
         final String functionName = newFunctionNode.getName();
         if (changed.contains(newFunctionNode.getId())) {
             newFunctionNode = newFunctionNode.clearFlag(lc, FunctionNode.USES_ARGUMENTS).
                     setFlag(lc, FunctionNode.HAS_APPLY_TO_CALL_SPECIALIZATION).
                     setParameters(lc, explodedArguments.peek());
             if (log.isEnabled()) {
                 log.info("Successfully specialized apply to call in '",
                         functionName,
                         " params=",
                         explodedArguments.peek(),
                         "' id=",
                         newFunctionNode.getId(),
                         " source=",
                         newFunctionNode.getSource().getURL());
             }
         }
         explodedArguments.pop();
         return newFunctionNode.setState(lc, CompilationState.BUILTINS_TRANSFORMED);
     }
     private static boolean isApply(final CallNode callNode) {
         final Expression f = callNode.getFunction();
         return f instanceof AccessNode && "apply".equals(((AccessNode)f).getProperty());
     }
 }

Mercurial > jdk8-mips64-public > nashorn / annotate

src/jdk/nashorn/internal/codegen/ApplySpecialization.java@03c06c337d9d (annotated)

src/jdk/nashorn/internal/codegen/ApplySpecialization.java