1 /*
   2  * Copyright (c) 2018, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have
  23  * questions.
  24  */
  25 package jdk.incubator.vector;
  26 
  27 import java.util.function.IntUnaryOperator;
  28 
  29 abstract class AbstractShuffle<E> extends Shuffle<E> {
  30     static final IntUnaryOperator IDENTITY = i -> i;
  31 
  32     // Internal representation allows for a maximum index of 256
  33     // Values are masked by (species().length() - 1)
  34     final byte[] reorder;
  35 
  36     AbstractShuffle(byte[] reorder) {
  37         this.reorder = reorder;
  38     }
  39 
  40     public AbstractShuffle(int[] reorder) {
  41         this(reorder, 0);
  42     }
  43 
  44     public AbstractShuffle(int[] reorder, int offset) {
  45         byte[] a = new byte[species().length()];
  46         for (int i = 0; i < a.length; i++) {
  47             a[i] = (byte) (reorder[offset + i] & (a.length - 1));
  48         }
  49         this.reorder = a;
  50     }
  51 
  52     public AbstractShuffle(IntUnaryOperator f) {
  53         byte[] a = new byte[species().length()];
  54         for (int i = 0; i < a.length; i++) {
  55             a[i] = (byte) (f.applyAsInt(i) & (a.length - 1));
  56         }
  57         this.reorder = a;
  58     }
  59 
  60     @Override
  61     public void intoArray(int[] a, int offset) {
  62         for (int i = 0; i < reorder.length; i++) {
  63             a[i] = reorder[i];
  64         }
  65     }
  66 
  67     @Override
  68     public int[] toArray() {
  69         int[] a = new int[reorder.length];
  70         intoArray(a, 0);
  71         return a;
  72     }
  73 
  74     @Override
  75     public int getElement(int i) {
  76         return reorder[i];
  77     }
  78 
  79 }