--- /dev/null 2017-01-22 10:16:57.869617664 -0800 +++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.replacements/src/org/graalvm/compiler/replacements/IntegerSubstitutions.java 2017-02-15 17:09:06.220093562 -0800 @@ -0,0 +1,48 @@ +/* + * Copyright (c) 2012, 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 org.graalvm.compiler.replacements; + +import org.graalvm.compiler.api.replacements.ClassSubstitution; +import org.graalvm.compiler.api.replacements.MethodSubstitution; +import org.graalvm.compiler.replacements.nodes.BitScanForwardNode; +import org.graalvm.compiler.replacements.nodes.BitScanReverseNode; + +@ClassSubstitution(Integer.class) +public class IntegerSubstitutions { + + @MethodSubstitution + public static int numberOfLeadingZeros(int i) { + if (i == 0) { + return 32; + } + return 31 - BitScanReverseNode.unsafeScan(i); + } + + @MethodSubstitution + public static int numberOfTrailingZeros(int i) { + if (i == 0) { + return 32; + } + return BitScanForwardNode.unsafeScan(i); + } +}