| /* ==================================================================== |
| Licensed to the Apache Software Foundation (ASF) under one or more |
| contributor license agreements. See the NOTICE file distributed with |
| this work for additional information regarding copyright ownership. |
| The ASF licenses this file to You under the Apache License, Version 2.0 |
| (the "License"); you may not use this file except in compliance with |
| the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| ==================================================================== */ |
| |
| package org.apache.poi.ss.util; |
| |
| |
| /** |
| * For working with the internals of IEEE 754-2008 'binary64' (double precision) floating point numbers |
| * |
| * @author Josh Micich |
| */ |
| final class IEEEDouble { |
| private static final long EXPONENT_MASK = 0x7FF0000000000000L; |
| private static final int EXPONENT_SHIFT = 52; |
| public static final long FRAC_MASK = 0x000FFFFFFFFFFFFFL; |
| public static final int EXPONENT_BIAS = 1023; |
| public static final long FRAC_ASSUMED_HIGH_BIT = ( 1L<<EXPONENT_SHIFT ); |
| /** |
| * The value the exponent field gets for all <i>NaN</i> and <i>Infinity</i> values |
| */ |
| public static final int BIASED_EXPONENT_SPECIAL_VALUE = 0x07FF; |
| |
| /** |
| * @param rawBits the 64 bit binary representation of the double value |
| * @return the top 12 bits (sign and biased exponent value) |
| */ |
| public static int getBiasedExponent(long rawBits) { |
| return (int) ((rawBits & EXPONENT_MASK) >> EXPONENT_SHIFT); |
| } |
| } |