1 /*
   2  * Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package org.graalvm.compiler.replacements;
  24 
  25 import org.graalvm.compiler.api.replacements.ClassSubstitution;
  26 import org.graalvm.compiler.api.replacements.MethodSubstitution;
  27 import org.graalvm.compiler.replacements.nodes.BitScanForwardNode;
  28 import org.graalvm.compiler.replacements.nodes.BitScanReverseNode;
  29 
  30 // JaCoCo Exclude
  31 
  32 @ClassSubstitution(Long.class)
  33 public class LongSubstitutions {
  34 
  35     @MethodSubstitution
  36     public static int numberOfLeadingZeros(long i) {
  37         if (i == 0) {
  38             return 64;
  39         }
  40         return 63 - BitScanReverseNode.unsafeScan(i);
  41     }
  42 
  43     @MethodSubstitution
  44     public static int numberOfTrailingZeros(long i) {
  45         if (i == 0) {
  46             return 64;
  47         }
  48         return BitScanForwardNode.unsafeScan(i);
  49     }
  50 }