Mercurial > hg > truffle
view graal/com.oracle.graal.replacements/src/com/oracle/graal/replacements/nodes/BitScanForwardNode.java @ 13910:d25c52a893d9
Add specialization for int to BitScanForwardNode to avoid unnecessary sign-extension to long.
Contributed-by: Daniel Sturm <d.sturm42@gmail.com>
author | Gilles Duboscq <duboscq@ssw.jku.at> |
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date | Fri, 07 Feb 2014 17:51:14 +0100 |
parents | da9db8331658 |
children | 34c07ef28bc9 |
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/* * Copyright (c) 2012, 2012, 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.replacements.nodes; import com.oracle.graal.api.meta.*; import com.oracle.graal.compiler.gen.*; import com.oracle.graal.compiler.target.*; import com.oracle.graal.graph.*; import com.oracle.graal.graph.spi.*; import com.oracle.graal.lir.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.calc.*; import com.oracle.graal.nodes.type.*; public class BitScanForwardNode extends FloatingNode implements LIRGenLowerable, Canonicalizable { @Input private ValueNode value; public BitScanForwardNode(ValueNode value) { super(StampFactory.forInteger(Kind.Int, 0, value.kind().getBitCount())); this.value = value; } @Override public Node canonical(CanonicalizerTool tool) { if (value.isConstant()) { long v = value.asConstant().asLong(); if (value.kind().getStackKind() == Kind.Int) { return ConstantNode.forInt(Integer.numberOfTrailingZeros((int) v), graph()); } else if (value.kind() == Kind.Long) { return ConstantNode.forInt(Long.numberOfTrailingZeros(v), graph()); } } return this; } @NodeIntrinsic public static int scan(long v) { if (v == 0) { return -1; } int index = 0; while (((1L << index) & v) == 0) { ++index; } return index; } @NodeIntrinsic public static int scan(int v) { return scan(v & 0xFFFFFFFFL); } @Override public void generate(LIRGenerator gen) { Variable result = gen.newVariable(Kind.Int); gen.emitBitScanForward(result, gen.operand(value)); gen.setResult(this, result); } }