text: /**
  * @license Apache-2.0
  *
  * Copyright (c) 2018 The Stdlib Authors.
  *
  * Licensed 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.
  */
  
  'use strict';
  
  // MODULES //
  
  var tape = require( 'tape' );
  var PINF = require( '@stdlib/constants/float64/pinf' );
  var NINF = require( '@stdlib/constants/float64/ninf' );
  var lpad = require( '@stdlib/string/left-pad' );
  var repeat = require( '@stdlib/string/repeat' );
  var pow = require( '@stdlib/math/base/special/pow' );
  var toBinaryString = require( './../../../../float64/base/to-binary-string' );
  var isInteger = require( '@stdlib/math/base/assert/is-integer' );
  var Uint32Array = require( '@stdlib/array/uint32' );
  var toWords = require( './../lib' );
  
  
  // TESTS //
  
  tape( 'main export is a function', function test( t ) {
  	t.ok( true, __filename );
  	t.equal( typeof toWords, 'function', 'main export is a function' );
  	t.end();
  });
  
  tape( 'the function returns a two-element numeric array containing integers', function test( t ) {
  	var w = toWords( pow( 2.0, 53 ) );
  
  	t.equal( typeof w[ 0 ], 'number', 'first element is a number' );
  	t.equal( isInteger( w[0] ), true, 'first element is an integer' );
  
  	t.equal( typeof w[ 1 ], 'number', 'second element is a number' );
  	t.equal( isInteger( w[1] ), true, 'second element is an integer' );
  
  	t.end();
  });
  
  tape( 'the function splits a floating-point number into a higher order word and a lower order word', function test( t ) {
  	var expected;
  	var values;
  	var high;
  	var low;
  	var str;
  	var v;
  	var w;
  	var i;
  
  	values = [
  		5.0,
  		pow( 2.0, 53 ),
  		1.0e308,
  		-1.0e308,
  		-3.14,
  		1.0e-324,
  		4.94e-324,
  		1.234567890123456789,
  		-4.94e-324,
  		6.333333333333333333e-310,
  		-0.0,
  		0.0,
  		100.0,
  		1.0/10.0,
  		0.625,
  		1.0/3.0,
  		5.0e-240,
  		-5.0e-240,
  		10.0,
  		15.0,
  		-10.0,
  		-15.0,
  		pow( 2.0, -42 ),
  		-pow( 2.0, 100 ),
  		1.0,
  		-1.0,
  		1.5,
  		1111111111111.111111111,
  		-1111111111111.111111111,
  		pow( 2.0, 54 ),
  		pow( 2.0, 53 ) + 1.0,
  		pow( 2.0, 53 ) + 2.0,
  		pow( 2.0, 55 ),
  		pow( 2.0, 56 ) - 1.0,
  		-pow( 2.0, 57 ) + 5.0,
  		3.0*pow( 2.0, 53 ),
  		8.0*pow( 2.0, 54 )
  	];
  
  	for ( i = 0; i < values.length; i++ ) {
  		v = values[ i ];
  		w = toWords( v );
  
  		// Convert to binary strings:
  		high = w[ 0 ].toString( 2 );
  		low = w[ 1 ].toString( 2 );
  
  		// Combine into a single bit literal:
  		if ( v > 0 ) {
  			str = '0'; // sign bit
  			str += lpad( high, 31, '0' );
  		} else {
  			str = lpad( high, 32, '0' );
  		}
  		str += lpad( low, 32, '0' );
  
  		expected = toBinaryString( v );
  		t.equal( str, expected, 'high+low equals bit string for ' + v );
  	}
  	t.end();
  });
  
  tape( 'if provided `NaN`, the sign bit may be either 0 or 1, the exponent must be all 1s, and the fraction cannot be all 0s (IEEE 754-1985)', function test( t ) {
  	var frac;
  	var high;
  	var low;
  	var w;
  
  	w = toWords( NaN );
  
  	// Convert to binary strings...
  	high = w[ 0 ].toString( 2 );
  	low = w[ 1 ].toString( 2 );
  
  	// Pad...
  	high = lpad( high, 32, '0' );
  	low = lpad( low, 32, '0' );
  
  	// Sign: +-1.
  	t.ok( high[0] === '1' || high[0] === '0', 'sign is either 1 or 0' );
  
  	// Exponent all 1s.
  	t.equal( high.substring( 1, 12 ), '11111111111', 'exponent all 1s' );
  
  	// Fraction cannot be all zeros.
  	frac = repeat( '0', 52 );
  
  	t.ok( high.substring( 12 ) !== frac.substring( 0, 32-12 ) || low !== frac.substring( 32-12 ), 'fraction not all 0s' );
  
  	t.end();
  });
  
  tape( 'if provided `+infinity`, the higher order word corresponds to a sign of 0, all 1s in the exponent, and all 0s in the fraction, while the lower order word is all 0s (IEEE 754-1985)', function test( t ) {
  	var high;
  	var low;
  	var w;
  
  	high = '0'; // sign
  	high += repeat( '1', 11 ); // exponent
  	high += repeat( '0', 20 ); // fraction
  	high = parseInt( high, 2 );
  
  	low = repeat( '0', 32 );
  	low = parseInt( low, 2 );
  
  	w = toWords( PINF );
  	t.equal( w[0], high, 'equals high word' );
  	t.equal( w[1], low, 'equals low word' );
  	t.end();
  });
  
  tape( 'if provided `-infinity`, the higher order word corresponds to a sign of 1, all 1s in the exponent, and all 0s in the fraction, while the lower order word is all 0s (IEEE 754-1985)', function test( t ) {
  	var high;
  	var low;
  	var w;
  
  	high = '1'; // sign
  	high += repeat( '1', 11 ); // exponent
  	high += repeat( '0', 20 ); // fraction
  	high = parseInt( high, 2 );
  
  	low = repeat( '0', 32 ); // fraction
  	low = parseInt( low, 2 );
  
  	w = toWords( NINF );
  	t.equal( w[0], high, 'equals high word' );
  	t.equal( w[1], low, 'equals low word' );
  	t.end();
  });
  
  tape( 'the function supports providing an output object (array)', function test( t ) {
  	var expected;
  	var out;
  	var w;
  
  	expected = toWords( pow( 2.0, 53 ) );
  
  	out = [ 0, 0 ];
  	w = toWords( out, pow( 2.0, 53 ) );
  
  	t.equal( w, out, 'returns output array' );
  	t.equal( w[ 0 ], expected[ 0 ], 'returns expected higher order word' );
  	t.equal( w[ 1 ], expected[ 1 ], 'returns expected lower order word' );
  
  	t.end();
  });
  
  tape( 'the function supports providing an output object (typed array)', function test( t ) {
  	var expected;
  	var out;
  	var w;
  
  	expected = toWords( pow( 2.0, 53 ) );
  
  	out = new Uint32Array( 2 );
  	w = toWords( out, pow( 2.0, 53 ) );
  
  	t.equal( w, out, 'returns output array' );
  	t.equal( w[ 0 ], expected[ 0 ], 'returns expected higher order word' );
  	t.equal( w[ 1 ], expected[ 1 ], 'returns expected lower order word' );
  
  	t.end();
  });
  
  tape( 'the function supports providing an output object (object)', function test( t ) {
  	var expected;
  	var out;
  	var w;
  
  	expected = toWords( pow( 2.0, 53 ) );
  
  	out = {
  		'length': 2,
  		'0': 0,
  		'1': 0
  	};
  	w = toWords( out, pow( 2.0, 53 ) );
  
  	t.equal( w, out, 'returns output array' );
  	t.equal( w[ 0 ], expected[ 0 ], 'returns expected higher order word' );
  	t.equal( w[ 1 ], expected[ 1 ], 'returns expected lower order word' );
  
  	t.end();
  });
  