118 lines
2.5 KiB
Markdown
118 lines
2.5 KiB
Markdown
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<!--
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@license Apache-2.0
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Copyright (c) 2018 The Stdlib Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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-->
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# Bitwise Rotation
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> Bitwise rotation to the left.
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<section class="usage">
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## Usage
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```javascript
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var rotl32 = require( '@stdlib/number/uint32/base/rotl' );
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```
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#### rotl32( x, shift )
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Performs a bitwise rotation to the left.
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```javascript
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var toBinaryStringUint32 = require( '@stdlib/number/uint32/base/to-binary-string' );
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var x = 2147483649;
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var bstr = toBinaryStringUint32( x );
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// returns '10000000000000000000000000000001'
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var y = rotl32( x, 10 );
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// returns 1536
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bstr = toBinaryStringUint32( y );
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// returns '00000000000000000000011000000000'
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```
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</section>
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<!-- /.usage -->
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<section class="notes">
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## Notes
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- If provided a `shift` equal to `0`, the function returns the input value.
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```javascript
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var y = rotl32( 3, 0 );
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// returns 3
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```
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- If provided a `shift` greater than `31`, the function performs a bitwise rotation based on the `5` least significant bits of `shift` (i.e., `shift % 32`).
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```javascript
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var shift = 34; // 00000000000000000000000000100010
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var y = rotl( 1, shift ); // 00000000000000000000000000000100
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// returns 4
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```
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</section>
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<!-- /.notes -->
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<section class="examples">
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## Examples
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<!-- eslint no-undef: "error" -->
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```javascript
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var toBinaryStringUint32 = require( '@stdlib/number/uint32/base/to-binary-string' );
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var MAX_INT = require( '@stdlib/constants/uint32/max' );
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var rotl32 = require( '@stdlib/number/uint32/base/rotl' );
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var HALF;
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var x;
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var y;
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var i;
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for ( i = 0; i < 100; i++ ) {
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x = i;
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y = rotl32( x, 10 );
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console.log( '%d => %s => %s => %d', x, toBinaryStringUint32( x ), toBinaryStringUint32( y ), y );
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}
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HALF = (MAX_INT+1) / 2;
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for ( i = 0; i < 100; i++ ) {
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x = HALF + i;
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y = rotl32( x, 10 );
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console.log( '%d => %s => %s => %d', x, toBinaryStringUint32( x ), toBinaryStringUint32( y ), y );
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}
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```
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</section>
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<!-- /.examples -->
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<section class="links">
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</section>
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<!-- /.links -->
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