FloatingPointFoldingTest.java revision 12158:0fe2815ffa74 
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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22 */
23
24/**
25 * @test
26 * @bug 8073670
27 * @summary Test that causes C2 to fold two NaNs with different values into a single NaN.
28 *
29 * @run main/othervm -XX:-TieredCompilation -Xcomp
30 *      -XX:CompileCommand=compileonly,compiler.c2.FloatingPointFoldingTest::test_double_inf
31 *      -XX:CompileCommand=compileonly,compiler.c2.FloatingPointFoldingTest::test_double_zero
32 *      -XX:CompileCommand=compileonly,compiler.c2.FloatingPointFoldingTest::test_double_nan
33 *      -XX:CompileCommand=compileonly,compiler.c2.FloatingPointFoldingTest::test_float_inf
34 *      -XX:CompileCommand=compileonly,compiler.c2.FloatingPointFoldingTest::test_float_zero
35 *      -XX:CompileCommand=compileonly,compiler.c2.FloatingPointFoldingTest::test_float_nan
36 *      compiler.c2.FloatingPointFoldingTest
37 */
38
39package compiler.c2;
40
41public class FloatingPointFoldingTest {
42    // Double values.
43    public static final long MINUS_INF_LONGBITS = 0xfff0000000000000L;
44    public static final double DOUBLE_MINUS_INF = Double.longBitsToDouble(MINUS_INF_LONGBITS);
45
46    public static final long PLUS_INF_LONGBITS = 0x7ff0000000000000L;
47    public static final double DOUBLE_PLUS_INF = Double.longBitsToDouble(PLUS_INF_LONGBITS);
48
49    public static final long MINUS_ZERO_LONGBITS = 0x8000000000000000L;
50    public static final double DOUBLE_MINUS_ZERO = Double.longBitsToDouble(MINUS_ZERO_LONGBITS);
51
52    // We need two different NaN values. A floating point number is
53    // considered to be NaN is the sign bit is 0, all exponent bits
54    // are set to 1, and at least one bit of the exponent is not zero.
55    //
56    // As java.lang.Double.NaN is 0x7ff8000000000000L, we use
57    // 0x7ffc000000000000L as a second NaN double value.
58    public static final long NAN_LONGBITS = 0x7ffc000000000000L;
59    public static final double DOUBLE_NAN = Double.longBitsToDouble(NAN_LONGBITS);
60
61    // Float values.
62    public static final int MINUS_INF_INTBITS = 0xff800000;
63    public static final float FLOAT_MINUS_INF = Float.intBitsToFloat(MINUS_INF_INTBITS);
64
65    public static final int PLUS_INF_INTBITS = 0x7f800000;
66    public static final float FLOAT_PLUS_INF = Float.intBitsToFloat(PLUS_INF_INTBITS);
67
68    public static final int MINUS_ZERO_INTBITS = 0x80000000;
69    public static final float FLOAT_MINUS_ZERO = Float.intBitsToFloat(MINUS_ZERO_INTBITS);
70
71    // As java.lang.Float.NaN is 0x7fc00000, we use 0x7fe00000
72    // as a second NaN float value.
73    public static final int NAN_INTBITS = 0x7fe00000;
74    public static final float FLOAT_NAN = Float.intBitsToFloat(NAN_INTBITS);
75
76
77    // Double tests.
78    static void test_double_inf(long[] result) {
79        double d1 = DOUBLE_MINUS_INF;
80        double d2 = DOUBLE_PLUS_INF;
81        result[0] = Double.doubleToRawLongBits(d1);
82        result[1] = Double.doubleToRawLongBits(d2);
83    }
84
85    static void test_double_zero(long[] result) {
86        double d1 = DOUBLE_MINUS_ZERO;
87        double d2 = 0;
88        result[0] = Double.doubleToRawLongBits(d1);
89        result[1] = Double.doubleToRawLongBits(d2);
90    }
91
92    static void test_double_nan(long[] result) {
93        double d1 = DOUBLE_NAN;
94        double d2 = Double.NaN;
95        result[0] = Double.doubleToRawLongBits(d1);
96        result[1] = Double.doubleToRawLongBits(d2);
97    }
98
99    // Float tests.
100    static void test_float_inf(int[] result) {
101        float f1 = FLOAT_MINUS_INF;
102        float f2 = FLOAT_PLUS_INF;
103        result[0] = Float.floatToRawIntBits(f1);
104        result[1] = Float.floatToRawIntBits(f2);
105    }
106
107    static void test_float_zero(int[] result) {
108        float f1 = FLOAT_MINUS_ZERO;
109        float f2 = 0;
110        result[0] = Float.floatToRawIntBits(f1);
111        result[1] = Float.floatToRawIntBits(f2);
112    }
113
114    static void test_float_nan(int[] result) {
115        float f1 = FLOAT_NAN;
116        float f2 = Float.NaN;
117        result[0] = Float.floatToRawIntBits(f1);
118        result[1] = Float.floatToRawIntBits(f2);
119    }
120
121    // Check doubles.
122    static void check_double(long[] result, double d1, double d2) {
123        if (result[0] == result[1]) {
124            throw new RuntimeException("ERROR: Two different double values are considered equal. \n"
125                                       + String.format("\toriginal values: 0x%x 0x%x\n", Double.doubleToRawLongBits(d1), Double.doubleToRawLongBits(d2))
126                                       + String.format("\tvalues after execution of method test(): 0x%x 0x%x", result[0], result[1]));
127        }
128    }
129
130    // Check floats.
131    static void check_float(int[] result, float f1, float f2) {
132        if (result[0] == result[1]) {
133            throw new RuntimeException("ERROR: Two different float values are considered equal. \n"
134                                       + String.format("\toriginal values: 0x%x 0x%x\n", Float.floatToRawIntBits(f1), Float.floatToRawIntBits(f2))
135                                       + String.format("\tvalues after execution of method test(): 0x%x 0x%x", result[0], result[1]));
136        }
137    }
138
139    public static void main(String[] args) {
140        // Float tests.
141
142        int[] iresult = new int[2];
143
144        // -Inf and +Inf.
145        test_float_inf(iresult);
146        check_float(iresult, FLOAT_MINUS_INF, FLOAT_PLUS_INF);
147
148        // 0 and -0.
149        test_float_zero(iresult);
150        check_float(iresult, FLOAT_MINUS_ZERO, 0);
151
152        // Diferrent NaNs.
153        test_float_nan(iresult);
154        check_float(iresult, FLOAT_NAN, Float.NaN);
155
156        // Double tests.
157
158        long[] lresult = new long[2];
159
160        // -Inf and +Inf.
161        test_double_inf(lresult);
162        check_double(lresult, DOUBLE_MINUS_INF, DOUBLE_PLUS_INF);
163
164        // 0 and -0.
165        test_double_zero(lresult);
166        check_double(lresult, DOUBLE_MINUS_ZERO, 0);
167
168        // Diferrent NaNs.
169        test_double_nan(lresult);
170        check_double(lresult, DOUBLE_NAN, Double.NaN);
171    }
172}
173