Add imuldw function

lib/node_modules/@stdlib/math/base/special/imuldw/README.md

@@ -0,0 +1,85 @@
+<!--
+
+@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.
+
+-->
+
+# imuldw
+
+> Compute the double word product of two signed 32-bit integers.
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var imuldw = require( '@stdlib/math/base/special/imuldw' );
+```
+
+#### imuldw( \[out,] a, b )
+
+Multiplies two signed 32-bit integers and returns an array of two signed 32-bit integers which represents the 64-bit signed integer product.
+
+```javascript
+var v = imuldw( 1, 10 );
+// returns [ 0, 10 ]
+
+v = imuldw( 0x80000000, 0x40000000 ); // -2^31 * 2^30 = -2305843009213694000 => 32-bit integer overflow
+// returns [ -536870912, 0 ]
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var lpad = require( '@stdlib/string/left-pad' );
+var imuldw = require( '@stdlib/math/base/special/imuldw' );
+
+var i;
+var j;
+var y;
+
+for ( i = 0xFFFFFFF0; i < 0xFFFFFFFF; i++ ) {
+    for ( j = i; j < 0xFFFFFFFF; j++) {
+        y = imuldw( i, j );
+        console.log( '%d x %d = 0x%s%s', i, j, lpad( ( y[0] >>> 0 ).toString( 16 ), 8, '0'), lpad( ( y[1] >>> 0 ).toString( 16 ), 8, '0' ) );
+    }
+}
+```
+
+</section>
+
+<!-- /.examples -->
+
+<section class="links">
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/math/base/special/imuldw/benchmark/benchmark.js

@@ -0,0 +1,51 @@
+/**
+* @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 bench = require( '@stdlib/bench' );
+var minstd = require( '@stdlib/random/base/minstd' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var pkg = require( './../package.json' ).name;
+var imuldw = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg, function benchmark( b ) {
+	var x;
+	var y;
+	var i;
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		x = minstd();
+		y = imuldw( x, x );
+		if ( isnan( y ) ) {
+			b.fail( 'should not return NaN' );
+		}
+	}
+	b.toc();
+	if ( isnan( y ) ) {
+		b.fail( 'should not return NaN' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

lib/node_modules/@stdlib/math/base/special/imuldw/docs/repl.txt

@@ -0,0 +1,29 @@
+
+{{alias}}( [out,] a, b )
+    Multiplies two signed 32-bit integers and returns an array of two signed
+    32-bit integers which represents the 64-bit signed integer product.
+
+    Parameters
+    ----------
+    out: ArrayLikeObject (optional)
+        The output array.
+
+    a: integer
+        Signed 32-bit integer.
+
+    b: integer
+        Signed 32-bit integer.
+
+    Returns
+    -------
+    out: ArrayLikeObject
+        Double word product.
+
+    Examples
+    --------
+    > var v = {{alias}}( 1, 10 )
+    [ 0, 10 ]
+
+    See Also
+    --------
+

lib/node_modules/@stdlib/math/base/special/imuldw/examples/index.js

@@ -0,0 +1,33 @@
+/**
+* @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';
+
+var lpad = require( '@stdlib/string/left-pad' );
+var imuldw = require( './../lib' );
+
+var i;
+var j;
+var y;
+
+for ( i = 0xFFFFFFF0; i < 0xFFFFFFFF; i++ ) {
+	for ( j = i; j < 0xFFFFFFFF; j++) {
+		y = imuldw( i, j );
+		console.log( '%d x %d = 0x%s%s', i, j, lpad( ( y[0] >>> 0 ).toString( 16 ), 8, '0' ), lpad( ( y[1] >>> 0 ).toString( 16 ), 8, '0' ) );
+	}
+}

lib/node_modules/@stdlib/math/base/special/imuldw/lib/index.js

@@ -0,0 +1,40 @@
+/**
+* @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';
+
+/**
+* Perform multiplication of two signed 32-bit integers and return an array of two signed 32-bit integers which represents the 64-bit signed integer product.
+*
+* @module @stdlib/math/base/special/imuldw
+*
+* @example
+* var imuldw = require( '@stdlib/math/base/special/imuldw' );
+*
+* var v = imuldw( 0xAAAAAAAA, 0x55555555 );
+* // returns [ -477218589, 1908874354 ]
+*/
+
+// MODULES //
+
+var imuldw = require( './main.js' );
+
+
+// EXPORTS //
+
+module.exports = imuldw;

lib/node_modules/@stdlib/math/base/special/imuldw/lib/main.js

@@ -0,0 +1,101 @@
+/**
+* @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 isnan = require( '@stdlib/math/base/assert/is-nan' );
+
+
+// VARIABLES //
+
+// Define a mask for the least significant 16 bits (low word): 65535 => 0x0000ffff => 00000000000000001111111111111111
+var LOW_WORD_MASK = 0x0000ffff>>>0; // asm type annotation
+
+
+// MAIN //
+
+/**
+* Performs multiplication of two signed 32-bit integers and returns an array of two signed 32-bit integers which represents the 64-bit signed integer product.
+*
+* @param {ArrayLikeObject} [out] - output array
+* @param {uinteger32} a - integer
+* @param {uinteger32} b - integer
+* @returns {ArrayLikeObject} output array
+*
+* @example
+* var v = imuldw( 0xAAAAAAAA, 0x55555555 );
+* // returns [ -477218589, 1908874354 ]
+*/
+function imuldw() {
+	var out;
+	var w1;
+	var w2;
+	var w3;
+	var ha;
+	var hb;
+	var la;
+	var lb;
+	var a;
+	var b;
+	var t;
+	var k;
+
+	if ( arguments.length === 3 ) {
+		out = arguments[ 0 ];
+		a = arguments[ 1 ];
+		b = arguments[ 2 ];
+	} else {
+		out = [ 0, 0 ];
+		a = arguments[ 0 ];
+		b = arguments[ 1 ];
+	}
+	if ( isnan( a ) || isnan( b ) ) {
+		return NaN;
+	}
+	a |= 0; // asm type annotation
+	b |= 0; // asm type annotation
+
+	ha = ( a >> 16 ) | 0;
+	la = ( a & LOW_WORD_MASK ) >>> 0;
+
+	hb = ( b >> 16 ) | 0;
+	lb = ( b & LOW_WORD_MASK ) >>> 0;
+
+	t = ( la * lb ) >>> 0;
+	w3 = ( t & LOW_WORD_MASK ) >>> 0;
+	k = ( t >>> 16 ) >>> 0;
+
+	t = ( ( ha * lb ) + k ) >>> 0;
+	w2 = ( t & LOW_WORD_MASK ) >>> 0;
+	w1 = ( t >> 16 ) >>> 0;
+
+	t = ( ( la * hb ) + w2 ) >>> 0;
+	k = ( t >> 16 ) >>> 0;
+
+	out[ 0 ] = ( ( ha * hb ) + w1 + k ) | 0; // the higher 32 bits; convert to signed 32 bit
+	out[ 1 ] = ( ( t << 16 ) + w3 ) | 0; // the lower 32 bits; convert to signed 32 bit
+
+	return out;
+}
+
+
+// EXPORTS //
+
+module.exports = imuldw;