README.md (2422B)
1 <!-- 2 3 @license Apache-2.0 4 5 Copyright (c) 2018 The Stdlib Authors. 6 7 Licensed under the Apache License, Version 2.0 (the "License"); 8 you may not use this file except in compliance with the License. 9 You may obtain a copy of the License at 10 11 http://www.apache.org/licenses/LICENSE-2.0 12 13 Unless required by applicable law or agreed to in writing, software 14 distributed under the License is distributed on an "AS IS" BASIS, 15 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 See the License for the specific language governing permissions and 17 limitations under the License. 18 19 --> 20 21 # Significand Mask 22 23 > High word mask for the significand of a [double-precision floating-point number][ieee754]. 24 25 <section class="usage"> 26 27 ## Usage 28 29 <!-- eslint-disable id-length --> 30 31 ```javascript 32 var FLOAT64_HIGH_WORD_SIGNIFICAND_MASK = require( '@stdlib/constants/float64/high-word-significand-mask' ); 33 ``` 34 35 #### FLOAT64_HIGH_WORD_SIGNIFICAND_MASK 36 37 High word mask for the significand of a [double-precision floating-point number][ieee754]. 38 39 <!-- eslint-disable id-length --> 40 41 ```javascript 42 // 0x000fffff = 1048575 => 0 00000000000 11111111111111111111 43 var bool = ( FLOAT64_HIGH_WORD_SIGNIFICAND_MASK === 0x000fffff ); 44 // returns true 45 ``` 46 47 </section> 48 49 <!-- /.usage --> 50 51 <section class="notes"> 52 53 ## Notes 54 55 - The higher order word of a [double-precision floating-point number][ieee754] is a 32-bit integer containing the more significant bits which include the exponent and sign. 56 57 </section> 58 59 <!-- /.notes --> 60 61 <section class="examples"> 62 63 ## Examples 64 65 <!-- eslint-disable id-length --> 66 67 <!-- eslint no-undef: "error" --> 68 69 ```javascript 70 var getHighWord = require( '@stdlib/number/float64/base/get-high-word' ); 71 var FLOAT64_HIGH_WORD_SIGNIFICAND_MASK = require( '@stdlib/constants/float64/high-word-significand-mask' ); 72 73 var out; 74 var hi; 75 var x; 76 77 x = 11.5; 78 hi = getHighWord( x ); // => 0 10000000010 01110000000000000000 79 // returns 1076297728 80 81 // Mask off all bits except for the significand bits: 82 out = hi & FLOAT64_HIGH_WORD_SIGNIFICAND_MASK; // => 0 00000000000 01110000000000000000 83 // returns 458752 84 85 // Mask on the significand bits and leave other bits unchanged: 86 out = hi | FLOAT64_HIGH_WORD_SIGNIFICAND_MASK; // => 0 10000000010 11111111111111111111 87 // returns 1076887551 88 ``` 89 90 </section> 91 92 <!-- /.examples --> 93 94 <section class="links"> 95 96 [ieee754]: http://en.wikipedia.org/wiki/IEEE_754-1985 97 98 </section> 99 100 <!-- /.links -->