1 /*
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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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8  *
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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  *
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23 
24 import jdk.incubator.vector.*;
25 
26 import java.util.stream.IntStream;
27 
28 /**
29  * @test
30  * @modules jdk.incubator.vector
31  */
32 
33 public class VectorRuns {
34 
main(String[] args)35     public static void main(String[] args) {
36 
37         for (int i = 1; i < 1024; i++) {
38             int[] a = IntStream.range(0, 1024).toArray();
39             a[i] = -1;
40             countRunAscending(a);
41 
42             assertEquals(countRunAscending(a), i);
43             assertEquals(countRunAscendingVector(a), i);
44         }
45     }
46 
assertEquals(Object a, Object b)47     static void assertEquals(Object a, Object b) {
48         if (!a.equals(b)) throw new AssertionError(a + " " + b);
49     }
50 
51     // Count run of a[0] >  a[1] >  a[2] >  ...
countRunAscending(int[] a)52     static int countRunAscending(int[] a) {
53         int r = 1;
54         if (r >= a.length)
55             return a.length;
56 
57         while (r < a.length && a[r - 1] <= a[r]) {
58             r++;
59         }
60         return r;
61     }
62 
63 
countRunAscendingVector(int[] a)64     static int countRunAscendingVector(int[] a) {
65         VectorSpecies<Integer> species = IntVector.SPECIES_256;
66 
67         int r = 1;
68         if (r >= a.length)
69             return a.length;
70 
71         int length = a.length & (species.length() - 1);
72         if (length == a.length) length -= species.length();
73         while (r < length) {
74             IntVector vl = IntVector.fromArray(species, a, r - 1);
75             IntVector vr = IntVector.fromArray(species, a, r);
76             VectorMask<Integer> m = vl.compare(VectorOperators.GT, vr);
77             if (m.anyTrue())
78                 return r + Long.numberOfTrailingZeros(m.toLong());
79             r += species.length();
80         }
81 
82         while (r < a.length && a[r - 1] <= a[r]) {
83             r++;
84         }
85         return r;
86     }
87 }
88