FloatingPointFoldingTest.java revision 11707:ad7af1afda7a 
1/*
2 * Copyright (c) 2015, 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
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23 */
24
25/**
26 * @test
27 * @bug 8073670
28 * @summary Test that causes C2 to fold two NaNs with different values into a single NaN.
29 *
30 * @run main/othervm -XX:-TieredCompilation -Xcomp
31 *      -XX:CompileCommand=compileonly,compiler.c2.FloatingPointFoldingTest::test_double_inf
32 *      -XX:CompileCommand=compileonly,compiler.c2.FloatingPointFoldingTest::test_double_zero
33 *      -XX:CompileCommand=compileonly,compiler.c2.FloatingPointFoldingTest::test_double_nan
34 *      -XX:CompileCommand=compileonly,compiler.c2.FloatingPointFoldingTest::test_float_inf
35 *      -XX:CompileCommand=compileonly,compiler.c2.FloatingPointFoldingTest::test_float_zero
36 *      -XX:CompileCommand=compileonly,compiler.c2.FloatingPointFoldingTest::test_float_nan
37 *      compiler.c2.FloatingPointFoldingTest
38 */
39
40package compiler.c2;
41
42public class FloatingPointFoldingTest {
43    // Double values.
44    public static final long MINUS_INF_LONGBITS = 0xfff0000000000000L;
45    public static final double DOUBLE_MINUS_INF = Double.longBitsToDouble(MINUS_INF_LONGBITS);
46
47    public static final long PLUS_INF_LONGBITS = 0x7ff0000000000000L;
48    public static final double DOUBLE_PLUS_INF = Double.longBitsToDouble(PLUS_INF_LONGBITS);
49
50    public static final long MINUS_ZERO_LONGBITS = 0x8000000000000000L;
51    public static final double DOUBLE_MINUS_ZERO = Double.longBitsToDouble(MINUS_ZERO_LONGBITS);
52
53    // We need two different NaN values. A floating point number is
54    // considered to be NaN is the sign bit is 0, all exponent bits
55    // are set to 1, and at least one bit of the exponent is not zero.
56    //
57    // As java.lang.Double.NaN is 0x7ff8000000000000L, we use
58    // 0x7ffc000000000000L as a second NaN double value.
59    public static final long NAN_LONGBITS = 0x7ffc000000000000L;
60    public static final double DOUBLE_NAN = Double.longBitsToDouble(NAN_LONGBITS);
61
62    // Float values.
63    public static final int MINUS_INF_INTBITS = 0xff800000;
64    public static final float FLOAT_MINUS_INF = Float.intBitsToFloat(MINUS_INF_INTBITS);
65
66    public static final int PLUS_INF_INTBITS = 0x7f800000;
67    public static final float FLOAT_PLUS_INF = Float.intBitsToFloat(PLUS_INF_INTBITS);
68
69    public static final int MINUS_ZERO_INTBITS = 0x80000000;
70    public static final float FLOAT_MINUS_ZERO = Float.intBitsToFloat(MINUS_ZERO_INTBITS);
71
72    // As java.lang.Float.NaN is 0x7fc00000, we use 0x7fe00000
73    // as a second NaN float value.
74    public static final int NAN_INTBITS = 0x7fe00000;
75    public static final float FLOAT_NAN = Float.intBitsToFloat(NAN_INTBITS);
76
77
78    // Double tests.
79    static void test_double_inf(long[] result) {
80        double d1 = DOUBLE_MINUS_INF;
81        double d2 = DOUBLE_PLUS_INF;
82        result[0] = Double.doubleToRawLongBits(d1);
83        result[1] = Double.doubleToRawLongBits(d2);
84    }
85
86    static void test_double_zero(long[] result) {
87        double d1 = DOUBLE_MINUS_ZERO;
88        double d2 = 0;
89        result[0] = Double.doubleToRawLongBits(d1);
90        result[1] = Double.doubleToRawLongBits(d2);
91    }
92
93    static void test_double_nan(long[] result) {
94        double d1 = DOUBLE_NAN;
95        double d2 = Double.NaN;
96        result[0] = Double.doubleToRawLongBits(d1);
97        result[1] = Double.doubleToRawLongBits(d2);
98    }
99
100    // Float tests.
101    static void test_float_inf(int[] result) {
102        float f1 = FLOAT_MINUS_INF;
103        float f2 = FLOAT_PLUS_INF;
104        result[0] = Float.floatToRawIntBits(f1);
105        result[1] = Float.floatToRawIntBits(f2);
106    }
107
108    static void test_float_zero(int[] result) {
109        float f1 = FLOAT_MINUS_ZERO;
110        float f2 = 0;
111        result[0] = Float.floatToRawIntBits(f1);
112        result[1] = Float.floatToRawIntBits(f2);
113    }
114
115    static void test_float_nan(int[] result) {
116        float f1 = FLOAT_NAN;
117        float f2 = Float.NaN;
118        result[0] = Float.floatToRawIntBits(f1);
119        result[1] = Float.floatToRawIntBits(f2);
120    }
121
122    // Check doubles.
123    static void check_double(long[] result, double d1, double d2) {
124        if (result[0] == result[1]) {
125            throw new RuntimeException("ERROR: Two different double values are considered equal. \n"
126                                       + String.format("\toriginal values: 0x%x 0x%x\n", Double.doubleToRawLongBits(d1), Double.doubleToRawLongBits(d2))
127                                       + String.format("\tvalues after execution of method test(): 0x%x 0x%x", result[0], result[1]));
128        }
129    }
130
131    // Check floats.
132    static void check_float(int[] result, float f1, float f2) {
133        if (result[0] == result[1]) {
134            throw new RuntimeException("ERROR: Two different float values are considered equal. \n"
135                                       + String.format("\toriginal values: 0x%x 0x%x\n", Float.floatToRawIntBits(f1), Float.floatToRawIntBits(f2))
136                                       + String.format("\tvalues after execution of method test(): 0x%x 0x%x", result[0], result[1]));
137        }
138    }
139
140    public static void main(String[] args) {
141        // Float tests.
142
143        int[] iresult = new int[2];
144
145        // -Inf and +Inf.
146        test_float_inf(iresult);
147        check_float(iresult, FLOAT_MINUS_INF, FLOAT_PLUS_INF);
148
149        // 0 and -0.
150        test_float_zero(iresult);
151        check_float(iresult, FLOAT_MINUS_ZERO, 0);
152
153        // Diferrent NaNs.
154        test_float_nan(iresult);
155        check_float(iresult, FLOAT_NAN, Float.NaN);
156
157        // Double tests.
158
159        long[] lresult = new long[2];
160
161        // -Inf and +Inf.
162        test_double_inf(lresult);
163        check_double(lresult, DOUBLE_MINUS_INF, DOUBLE_PLUS_INF);
164
165        // 0 and -0.
166        test_double_zero(lresult);
167        check_double(lresult, DOUBLE_MINUS_ZERO, 0);
168
169        // Diferrent NaNs.
170        test_double_nan(lresult);
171        check_double(lresult, DOUBLE_NAN, Double.NaN);
172    }
173}
174