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11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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13  * accompanied this code).
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23 
24 /**
25  * @test
26  * @bug 7177917
27  * @summary Micro-benchmark for Math.pow() and Math.exp()
28  * @modules java.base/jdk.internal.misc
29  * @library /test/lib
30  *
31  * @run main compiler.c2.Test7177917
32  */
33 
34 package compiler.c2;
35 
36 import jdk.test.lib.Utils;
37 
38 import java.util.Random;
39 
40 public class Test7177917 {
41 
42   static double d;
43 
44   static final Random R = Utils.getRandomInstance();
45 
m_pow(double[][] values)46   static long  m_pow(double[][] values) {
47     double res = 0;
48     long start = System.nanoTime();
49     for (int i = 0; i < values.length; i++) {
50       res += Math.pow(values[i][0], values[i][1]);
51     }
52     long stop = System.nanoTime();
53     d = res;
54     return (stop - start) / 1000;
55   }
56 
m_exp(double[] values)57   static long  m_exp(double[] values) {
58     double res = 0;
59     long start = System.nanoTime();
60     for (int i = 0; i < values.length; i++) {
61       res += Math.exp(values[i]);
62     }
63     long stop = System.nanoTime();
64     d = res;
65     return (stop - start) / 1000;
66   }
67 
pow_values(int nb)68   static double[][] pow_values(int nb) {
69     double[][] res = new double[nb][2];
70     for (int i = 0; i < nb; i++) {
71       double ylogx = (1 + (R.nextDouble() * 2045)) - 1023; // 2045 rather than 2046 as a safety margin
72       double x = Math.abs(Double.longBitsToDouble(R.nextLong()));
73       while (x != x) {
74         x = Math.abs(Double.longBitsToDouble(R.nextLong()));
75       }
76       double logx = Math.log(x) / Math.log(2);
77       double y = ylogx / logx;
78 
79       res[i][0] = x;
80       res[i][1] = y;
81     }
82     return res;
83   }
84 
exp_values(int nb)85   static double[] exp_values(int nb) {
86     double[] res = new double[nb];
87     for (int i = 0; i < nb; i++) {
88       double ylogx = (1 + (R.nextDouble() * 2045)) - 1023; // 2045 rather than 2046 as a safety margin
89       double x = Math.E;
90       double logx = Math.log(x) / Math.log(2);
91       double y = ylogx / logx;
92       res[i] = y;
93     }
94     return res;
95   }
96 
main(String[] args)97   static public void main(String[] args) {
98     {
99       // warmup
100       double[][] warmup_values = pow_values(10);
101       m_pow(warmup_values);
102 
103       for (int i = 0; i < 20000; i++) {
104         m_pow(warmup_values);
105       }
106       // test pow perf
107       double[][] values = pow_values(1000000);
108       System.out.println("==> POW " + m_pow(values));
109 
110       // force uncommon trap
111       double[][] nan_values = new double[1][2];
112       nan_values[0][0] = Double.NaN;
113       nan_values[0][1] = Double.NaN;
114       m_pow(nan_values);
115 
116       // force recompilation
117       for (int i = 0; i < 20000; i++) {
118         m_pow(warmup_values);
119       }
120 
121       // test pow perf again
122       System.out.println("==> POW " + m_pow(values));
123     }
124     {
125       // warmup
126       double[] warmup_values = exp_values(10);
127       m_exp(warmup_values);
128 
129       for (int i = 0; i < 20000; i++) {
130         m_exp(warmup_values);
131       }
132 
133       // test pow perf
134       double[] values = exp_values(1000000);
135       System.out.println("==> EXP " + m_exp(values));
136 
137       // force uncommon trap
138       double[] nan_values = new double[1];
139       nan_values[0] = Double.NaN;
140       m_exp(nan_values);
141 
142       // force recompilation
143       for (int i = 0; i < 20000; i++) {
144         m_exp(warmup_values);
145       }
146 
147       // test pow perf again
148       System.out.println("==> EXP " + m_exp(values));
149     }
150   }
151 }
152