Mercurial > hg > graal-compiler
changeset 13635:e57115c41164
Make a separate phase to use trapping null checks instead of branches when implicitNullCheckLimit > 0
author | Gilles Duboscq <duboscq@ssw.jku.at> |
---|---|
date | Tue, 14 Jan 2014 16:27:14 +0100 |
parents | edc8e6410001 |
children | b9a5fa298461 |
files | graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/phases/LowTier.java graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/UseTrappingNullChecksPhase.java |
diffstat | 2 files changed, 82 insertions(+), 0 deletions(-) [+] |
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--- a/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/phases/LowTier.java Tue Jan 14 14:33:11 2014 +0100 +++ b/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/phases/LowTier.java Tue Jan 14 16:27:14 2014 +0100 @@ -40,6 +40,8 @@ appendPhase(new ExpandLogicPhase()); + appendPhase(new UseTrappingNullChecksPhase()); + appendPhase(new DeadCodeEliminationPhase()); } }
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/UseTrappingNullChecksPhase.java Tue Jan 14 16:27:14 2014 +0100 @@ -0,0 +1,80 @@ +/* + * Copyright (c) 2014, 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. + * + * 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.phases.common; + +import com.oracle.graal.graph.*; +import com.oracle.graal.nodes.*; +import com.oracle.graal.nodes.StructuredGraph.GuardsStage; +import com.oracle.graal.nodes.calc.*; +import com.oracle.graal.nodes.extended.*; +import com.oracle.graal.nodes.util.*; +import com.oracle.graal.phases.*; +import com.oracle.graal.phases.tiers.*; + +public class UseTrappingNullChecksPhase extends BasePhase<LowTierContext> { + + @Override + protected void run(StructuredGraph graph, LowTierContext context) { + if (context.getTarget().implicitNullCheckLimit <= 0) { + return; + } + assert graph.getGuardsStage().ordinal() >= GuardsStage.AFTER_FSA.ordinal(); + + for (DeoptimizeNode deopt : graph.getNodes(DeoptimizeNode.class)) { + tryUseTrappingNullCheck(deopt); + } + } + + private static void tryUseTrappingNullCheck(DeoptimizeNode deopt) { + Node predecessor = deopt.predecessor(); + Node branch = null; + while (predecessor instanceof AbstractBeginNode) { + branch = predecessor; + predecessor = predecessor.predecessor(); + } + if (predecessor instanceof IfNode) { + IfNode ifNode = (IfNode) predecessor; + if (branch != ifNode.trueSuccessor()) { + return; + } + LogicNode condition = ifNode.condition(); + if (condition instanceof IsNullNode) { + replaceWithTrappingNullCheck(deopt, ifNode, condition); + } + } + } + + private static void replaceWithTrappingNullCheck(DeoptimizeNode deopt, IfNode ifNode, LogicNode condition) { + IsNullNode isNullNode = (IsNullNode) condition; + AbstractBeginNode nonTrappingContinuation = ifNode.falseSuccessor(); + AbstractBeginNode trappingContinuation = ifNode.trueSuccessor(); + NullCheckNode trappingNullCheck = deopt.graph().add(new NullCheckNode(isNullNode.object())); + trappingNullCheck.setDeoptimizationState(deopt.getDeoptimizationState()); + deopt.graph().replaceSplit(ifNode, trappingNullCheck, nonTrappingContinuation); + + GraphUtil.killCFG(trappingContinuation); + if (isNullNode.usages().isEmpty()) { + GraphUtil.killWithUnusedFloatingInputs(isNullNode); + } + } +}