Mercurial > hg > truffle
view graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/GuardingPiNode.java @ 15388:769fc3629f59
Add phase FlowSensitiveReductionPhase.
It is possible to remove GuardingPiNodes, CheckCastNodes, and FixedGuards during
HighTier under certain conditions (control-flow sensitive conditions).
The phase added in this commit (FlowSensitiveReductionPhase) does that,
and in addition replaces usages with "downcasting" PiNodes when possible
thus resulting in more precise object stamps (e.g., non-null).
Finally, usages of floating, side-effects free, expressions are also simplified
(as per control-flow sensitive conditions).
The newly added phase runs only during HighTier and can be deactivated
using Graal option FlowSensitiveReduction (it is active by default).
author | Miguel Garcia <miguel.m.garcia@oracle.com> |
---|---|
date | Fri, 25 Apr 2014 16:50:52 +0200 |
parents | 61363577a184 |
children | 45285c8eccbd |
line wrap: on
line source
/* * Copyright (c) 2012, 2013, 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. * * 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 com.oracle.graal.nodes; import com.oracle.graal.api.meta.*; import com.oracle.graal.compiler.common.type.*; import com.oracle.graal.graph.*; import com.oracle.graal.graph.spi.*; import com.oracle.graal.nodes.calc.*; import com.oracle.graal.nodes.extended.*; import com.oracle.graal.nodes.spi.*; import com.oracle.graal.nodes.type.*; /** * A node that changes the stamp of its input based on some condition being true. */ @NodeInfo(nameTemplate = "GuardingPi(!={p#negated}) {p#reason/s}") public class GuardingPiNode extends FixedWithNextNode implements Lowerable, Virtualizable, Canonicalizable, ValueProxy { @Input private ValueNode object; @Input(InputType.Condition) private LogicNode condition; private final DeoptimizationReason reason; private final DeoptimizationAction action; private boolean negated; public ValueNode object() { return object; } public LogicNode condition() { return condition; } public boolean isNegated() { return negated; } public DeoptimizationReason getReason() { return reason; } public DeoptimizationAction getAction() { return action; } /** * Constructor for {@link #guardingNonNull(Object)} node intrinsic. */ private GuardingPiNode(ValueNode object) { this(object, object.graph().unique(new IsNullNode(object)), true, DeoptimizationReason.NullCheckException, DeoptimizationAction.None, object.stamp().join(StampFactory.objectNonNull())); } /** * Creates a guarding pi node. * * @param object the object whose type is refined if this guard succeeds * @param condition the condition to test * @param negateCondition the guard succeeds if {@code condition != negateCondition} * @param stamp the refined type of the object if the guard succeeds */ public GuardingPiNode(ValueNode object, ValueNode condition, boolean negateCondition, DeoptimizationReason reason, DeoptimizationAction action, Stamp stamp) { super(stamp); assert stamp != null; this.object = object; this.condition = (LogicNode) condition; this.reason = reason; this.action = action; this.negated = negateCondition; } @Override public void lower(LoweringTool tool) { GuardingNode guard = tool.createGuard(next(), condition, reason, action, negated); ValueAnchorNode anchor = graph().add(new ValueAnchorNode((ValueNode) guard)); PiNode pi = graph().unique(new PiNode(object, stamp(), (ValueNode) guard)); replaceAtUsages(pi); graph().replaceFixedWithFixed(this, anchor); } @Override public void virtualize(VirtualizerTool tool) { State state = tool.getObjectState(object); if (state != null && state.getState() == EscapeState.Virtual && StampTool.typeOrNull(this) != null && StampTool.typeOrNull(this).isAssignableFrom(state.getVirtualObject().type())) { tool.replaceWithVirtual(state.getVirtualObject()); } } @Override public boolean inferStamp() { return updateStamp(stamp().join(object().stamp())); } @Override public Node canonical(CanonicalizerTool tool) { if (stamp() == StampFactory.illegal(object.getKind())) { // The guard always fails return graph().add(new DeoptimizeNode(action, reason)); } if (condition instanceof LogicConstantNode) { LogicConstantNode c = (LogicConstantNode) condition; if (c.getValue() == negated) { // The guard always fails return graph().add(new DeoptimizeNode(action, reason)); } else if (stamp().equals(object().stamp())) { // The guard always succeeds, and does not provide new type information return object; } else { // The guard always succeeds, and provides new type information return graph().unique(new PiNode(object, stamp())); } } return this; } @NodeIntrinsic public static <T> T guardingNonNull(T object) { if (object == null) { throw new NullPointerException(); } return object; } @NodeIntrinsic public static native Object guardingPi(Object object, LogicNode condition, @ConstantNodeParameter boolean negateCondition, @ConstantNodeParameter DeoptimizationReason reason, @ConstantNodeParameter DeoptimizationAction action, @ConstantNodeParameter Stamp stamp); @Override public ValueNode getOriginalNode() { return object; } }