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1 /* |
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2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
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22 */ |
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23 |
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24 /** |
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25 * Common library for additional constants of the {@code double} type. |
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26 */ |
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27 public final class DoubleConsts { |
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28 /** |
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29 * Don't let anyone instantiate this class. |
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30 */ |
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31 private DoubleConsts() {} |
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32 |
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33 /** |
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34 * Bias used in representing a {@code double} exponent. |
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35 */ |
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36 public static final int EXP_BIAS = 1023; |
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37 |
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38 /** |
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39 * Bit mask to isolate the exponent field of a {@code double}. |
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40 */ |
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41 public static final long EXP_BIT_MASK = 0x7FF0000000000000L; |
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42 |
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43 /** |
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44 * Bit mask to isolate the sign bit of a {@code double}. |
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45 */ |
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46 public static final long SIGN_BIT_MASK = 0x8000000000000000L; |
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47 |
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48 /** |
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49 * Bit mask to isolate the significand field of a {@code double}. |
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50 */ |
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51 public static final long SIGNIF_BIT_MASK = 0x000FFFFFFFFFFFFFL; |
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52 |
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53 /** |
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54 * The number of logical bits in the significand of a |
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55 * {@code double} number, including the implicit bit. |
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56 */ |
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57 public static final int SIGNIFICAND_WIDTH = 53; |
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58 |
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59 /** |
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60 * The exponent the smallest positive {@code double} |
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61 * subnormal value would have if it could be normalized. |
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62 */ |
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63 public static final int MIN_SUB_EXPONENT = Double.MIN_EXPONENT - |
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64 (SIGNIFICAND_WIDTH - 1); |
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65 |
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66 static { |
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67 // verify bit masks cover all bit positions and that the bit |
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68 // masks are non-overlapping |
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69 assert(((SIGN_BIT_MASK | EXP_BIT_MASK | SIGNIF_BIT_MASK) == ~0L) && |
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70 (((SIGN_BIT_MASK & EXP_BIT_MASK) == 0L) && |
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71 ((SIGN_BIT_MASK & SIGNIF_BIT_MASK) == 0L) && |
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72 ((EXP_BIT_MASK & SIGNIF_BIT_MASK) == 0L))); |
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73 } |
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74 } |