Mercurial > hg > openjdk > lambda > nashorn
view src/jdk/nashorn/internal/codegen/BranchOptimizer.java @ 658:0ecbc0188b64
8027031: complete merging of loads and converts
Reviewed-by: jlaskey, lagergren
author | attila |
---|---|
date | Tue, 22 Oct 2013 16:43:27 +0200 |
parents | 2d5f9f77c199 |
children |
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/* * Copyright (c) 2010, 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. 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.Condition.EQ; import static jdk.nashorn.internal.codegen.Condition.GE; import static jdk.nashorn.internal.codegen.Condition.GT; import static jdk.nashorn.internal.codegen.Condition.LE; import static jdk.nashorn.internal.codegen.Condition.LT; import static jdk.nashorn.internal.codegen.Condition.NE; import jdk.nashorn.internal.codegen.types.Type; import jdk.nashorn.internal.ir.BinaryNode; import jdk.nashorn.internal.ir.Expression; import jdk.nashorn.internal.ir.TernaryNode; import jdk.nashorn.internal.ir.UnaryNode; /** * Branch optimizer for CodeGenerator. Given a jump condition this helper * class attempts to simplify the control flow */ final class BranchOptimizer { private final CodeGenerator codegen; private final MethodEmitter method; BranchOptimizer(final CodeGenerator codegen, final MethodEmitter method) { this.codegen = codegen; this.method = method; } void execute(final Expression node, final Label label, final boolean state) { branchOptimizer(node, label, state); } private void branchOptimizer(final UnaryNode unaryNode, final Label label, final boolean state) { final Expression rhs = unaryNode.rhs(); switch (unaryNode.tokenType()) { case NOT: branchOptimizer(rhs, label, !state); return; default: if (unaryNode.getType().isBoolean()) { branchOptimizer(rhs, label, state); return; } break; } // convert to boolean codegen.load(unaryNode, Type.BOOLEAN); if (state) { method.ifne(label); } else { method.ifeq(label); } } private void branchOptimizer(final BinaryNode binaryNode, final Label label, final boolean state) { final Expression lhs = binaryNode.lhs(); final Expression rhs = binaryNode.rhs(); switch (binaryNode.tokenType()) { case AND: if (state) { final Label skip = new Label("skip"); branchOptimizer(lhs, skip, false); branchOptimizer(rhs, label, true); method.label(skip); } else { branchOptimizer(lhs, label, false); branchOptimizer(rhs, label, false); } return; case OR: if (state) { branchOptimizer(lhs, label, true); branchOptimizer(rhs, label, true); } else { final Label skip = new Label("skip"); branchOptimizer(lhs, skip, true); branchOptimizer(rhs, label, false); method.label(skip); } return; case EQ: case EQ_STRICT: codegen.loadBinaryOperands(lhs, rhs, Type.widest(lhs.getType(), rhs.getType())); method.conditionalJump(state ? EQ : NE, true, label); return; case NE: case NE_STRICT: codegen.loadBinaryOperands(lhs, rhs, Type.widest(lhs.getType(), rhs.getType())); method.conditionalJump(state ? NE : EQ, true, label); return; case GE: codegen.loadBinaryOperands(lhs, rhs, Type.widest(lhs.getType(), rhs.getType())); method.conditionalJump(state ? GE : LT, !state, label); return; case GT: codegen.loadBinaryOperands(lhs, rhs, Type.widest(lhs.getType(), rhs.getType())); method.conditionalJump(state ? GT : LE, !state, label); return; case LE: codegen.loadBinaryOperands(lhs, rhs, Type.widest(lhs.getType(), rhs.getType())); method.conditionalJump(state ? LE : GT, state, label); return; case LT: codegen.loadBinaryOperands(lhs, rhs, Type.widest(lhs.getType(), rhs.getType())); method.conditionalJump(state ? LT : GE, state, label); return; default: break; } codegen.load(binaryNode, Type.BOOLEAN); if (state) { method.ifne(label); } else { method.ifeq(label); } } private void branchOptimizer(final Expression node, final Label label, final boolean state) { if (!(node instanceof TernaryNode)) { if (node instanceof BinaryNode) { branchOptimizer((BinaryNode)node, label, state); return; } if (node instanceof UnaryNode) { branchOptimizer((UnaryNode)node, label, state); return; } } codegen.load(node, Type.BOOLEAN); if (state) { method.ifne(label); } else { method.ifeq(label); } } }