feat: refactor JavaScript implementation and add C ndarray implemen…

…tation for `blas/base/sasum`

PR-URL: #2926
Ref: #2039
Co-authored-by: Athan Reines <kgryte@gmail.com>
Reviewed-by: Athan Reines <kgryte@gmail.com> 
Signed-off-by: Athan Reines <kgryte@gmail.com>

lib/node_modules/@stdlib/blas/base/sasum/README.md

@@ -97,7 +97,7 @@ var sum = sasum( 3, x1, 2 );
 // returns 12.0
 ```
 
-If either `N` or `stride` is less than or equal to `0`, the function returns `0`.
+If either `N` is less than or equal to `0`, the function returns `0`.
 
 #### sasum.ndarray( N, x, stride, offset )
 
@@ -170,6 +170,129 @@ console.log( out );
 
 <!-- /.examples -->
 
+<!-- C interface documentation. -->
+
+* * *
+
+<section class="c">
+
+## C APIs
+
+<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<!-- C usage documentation. -->
+
+<section class="usage">
+
+### Usage
+
+```c
+#include "stdlib/blas/base/sasum.h"
+```
+
+#### c_sasum( N, \*X, stride )
+
+Computes the sum of [absolute values][@stdlib/math/base/special/abs].
+
+```c
+const float x[] = { 1.0f, -2.0f, 3.0f, -4.0f, 5.0f, -6.0f, 7.0f, -8.0f };
+
+float sum = c_sasum( 8, x, 1 );
+// returns 36.0f
+```
+
+The function accepts the following arguments:
+
+-   **N**: `[in] CBLAS_INT` number of indexed elements.
+-   **X**: `[in] float*` input array.
+-   **stride**: `[in] CBLAS_INT` index increment for `X`.
+
+```c
+float c_sasum( const CBLAS_INT N, const float *X, const CBLAS_INT stride );
+```
+
+#### c_sasum_ndarray( N, \*X, stride, offset )
+
+Computes the sum of [absolute values][@stdlib/math/base/special/abs] using alternative indexing semantics.
+
+```c
+const float x[] = { 1.0f, -2.0f, 3.0f, -4.0f, 5.0f, -6.0f, 7.0f, -8.0f };
+
+float sum = c_sasum_ndarray( 8, x, -1, 7 );
+// returns 36.0f
+```
+
+The function accepts the following arguments:
+
+-   **N**: `[in] CBLAS_INT` number of indexed elements.
+-   **X**: `[in] float*` input array.
+-   **stride**: `[in] CBLAS_INT` index increment for `X`.
+-   **offset**: `[in] CBLAS_INT` starting index for `X`.
+
+```c
+float c_sasum_ndarray( const CBLAS_INT N, const float *X, const CBLAS_INT stride, const CBLAS_INT offset );
+```
+
+</section>
+
+<!-- /.usage -->
+
+<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="notes">
+
+</section>
+
+<!-- /.notes -->
+
+<!-- C API usage examples. -->
+
+<section class="examples">
+
+### Examples
+
+```c
+#include "stdlib/blas/base/sasum.h"
+#include <stdio.h>
+
+int main( void ) {
+    // Create a strided array:
+    const float x[] = { 1.0f, -2.0f, 3.0f, -4.0f, 5.0f, -6.0f, 7.0f, -8.0f };
+
+    // Specify the number of elements:
+    const int N = 8;
+
+    // Specify a stride:
+    const int stride = 1;
+
+    // Compute the sum of absolute values:
+    float sum = c_sasum( N, x, stride );
+
+    // Print the result:
+    printf( "sum: %f\n", sum );
+
+    // Compute the sum of absolute values:
+    sum = c_sasum_ndarray( N, x, -stride, N-1 );
+
+    // Print the result:
+    printf( "sum: %f\n", sum );
+}
+```
+
+</section>
+
+<!-- /.examples -->
+
+</section>
+
+<!-- /.c -->
+
 <!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
 
 <section class="related">

lib/node_modules/@stdlib/blas/base/sasum/benchmark/c/benchmark.length.c

@@ -94,7 +94,7 @@ static float rand_float( void ) {
 * @param len          array length
 * @return elapsed time in seconds
 */
-static double benchmark( int iterations, int len ) {
+static double benchmark1( int iterations, int len ) {
 	double elapsed;
 	float x[ len ];
 	float y;
@@ -120,6 +120,39 @@ static double benchmark( int iterations, int len ) {
 	return elapsed;
 }
 
+/**
+* Runs a benchmark.
+*
+* @param iterations   number of iterations
+* @param len          array length
+* @return elapsed time in seconds
+*/
+static double benchmark2( int iterations, int len ) {
+	double elapsed;
+	float x[ len ];
+	float y;
+	double t;
+	int i;
+
+	for ( i = 0; i < len; i++ ) {
+		x[ i ] = ( rand_float()*20000.0f ) - 10000.0f;
+	}
+	y = 0.0f;
+	t = tic();
+	for ( i = 0; i < iterations; i++ ) {
+		y = c_sasum_ndarray( len, x, 1, 0 );
+		if ( y != y ) {
+			printf( "should not return NaN\n" );
+			break;
+		}
+	}
+	elapsed = tic() - t;
+	if ( y != y ) {
+		printf( "should not return NaN\n" );
+	}
+	return elapsed;
+}
+
 /**
 * Main execution sequence.
 */
@@ -142,7 +175,14 @@ int main( void ) {
 		for ( j = 0; j < REPEATS; j++ ) {
 			count += 1;
 			printf( "# c::%s:len=%d\n", NAME, len );
-			elapsed = benchmark( iter, len );
+			elapsed = benchmark1( iter, len );
+			print_results( iter, elapsed );
+			printf( "ok %d benchmark finished\n", count );
+		}
+		for ( j = 0; j < REPEATS; j++ ) {
+			count += 1;
+			printf( "# c::%s:ndarray:len=%d\n", NAME, len );
+			elapsed = benchmark2( iter, len );
 			print_results( iter, elapsed );
 			printf( "ok %d benchmark finished\n", count );
 		}

lib/node_modules/@stdlib/blas/base/sasum/docs/repl.txt

@@ -10,7 +10,7 @@
     Indexing is relative to the first index. To introduce an offset, use typed
     array views.
 
-    If `N` or `stride` is less than or equal to `0`, the function returns `0`.
+    If `N` is less than or equal to `0`, the function returns `0`.
 
     Parameters
     ----------

lib/node_modules/@stdlib/blas/base/sasum/examples/c/example.c

@@ -27,10 +27,16 @@ int main( void ) {
 	const int N = 8;
 
 	// Specify a stride:
-	const int strideX = 1;
+	const int stride = 1;
 
 	// Compute the sum of absolute values:
-	float sum = c_sasum( N, x, strideX );
+	float sum = c_sasum( N, x, stride );
+
+	// Print the result:
+	printf( "sum: %f\n", sum );
+
+	// Compute the sum of absolute values:
+	sum = c_sasum_ndarray( N, x, -stride, N-1 );
 
 	// Print the result:
 	printf( "sum: %f\n", sum );

lib/node_modules/@stdlib/blas/base/sasum/include/stdlib/blas/base/sasum.h

@@ -22,6 +22,8 @@
 #ifndef SASUM_H
 #define SASUM_H
 
+#include "stdlib/blas/base/shared.h"
+
 /*
 * If C++, prevent name mangling so that the compiler emits a binary file having undecorated names, thus mirroring the behavior of a C compiler.
 */
@@ -32,7 +34,12 @@ extern "C" {
 /**
 * Computes the sum of absolute values.
 */
-float c_sasum( const int N, const float *X, const int stride );
+float API_SUFFIX(c_sasum)( const CBLAS_INT N, const float *X, const CBLAS_INT stride );
+
+/**
+* Computes the sum of absolute values using alternative indexing semantics.
+*/
+float API_SUFFIX(c_sasum_ndarray)( const CBLAS_INT N, const float *X, const CBLAS_INT stride, const CBLAS_INT offset );
 
 #ifdef __cplusplus
 }

lib/node_modules/@stdlib/blas/base/sasum/include/stdlib/blas/base/sasum_cblas.h

@@ -22,6 +22,8 @@
 #ifndef SASUM_CBLAS_H
 #define SASUM_CBLAS_H
 
+#include "stdlib/blas/base/shared"
+
 /*
 * If C++, prevent name mangling so that the compiler emits a binary file having undecorated names, thus mirroring the behavior of a C compiler.
 */
@@ -32,7 +34,7 @@ extern "C" {
 /**
 * Computes the sum of absolute values.
 */
-float cblas_sasum( const int N, const float *X, const int stride );
+float API_SUFFIX(cblas_sasum)( const CBLAS_INT N, const float *X, const CBLAS_INT stride );
 
 #ifdef __cplusplus
 }

lib/node_modules/@stdlib/blas/base/sasum/lib/ndarray.js

@@ -21,7 +21,7 @@
 // MODULES //
 
 var absf = require( '@stdlib/math/base/special/absf' );
-var float64ToFloat32 = require( '@stdlib/number/float64/base/to-float32' );
+var f32 = require( '@stdlib/number/float64/base/to-float32' );
 
 
 // MAIN //
@@ -32,7 +32,7 @@ var float64ToFloat32 = require( '@stdlib/number/float64/base/to-float32' );
 * @param {PositiveInteger} N - number of indexed elements
 * @param {Float32Array} x - input array
 * @param {integer} stride - `x` stride length
-* @param {NonNegativeInteger} offset - starting `x` index
+* @param {NonNegativeInteger} offset - starting index for `x`
 * @returns {number} sum
 *
 * @example
@@ -54,7 +54,7 @@ function sasum( N, x, stride, offset ) {
 	}
 	ix = offset;
 	for ( i = 0; i < N; i++ ) {
-		sum = float64ToFloat32( sum + absf( x[ix] ) );
+		sum = f32( sum + absf( x[ ix ] ) );
 		ix += stride;
 	}
 	return sum;

lib/node_modules/@stdlib/blas/base/sasum/lib/ndarray.native.js

@@ -20,9 +20,7 @@
 
 // MODULES //
 
-var minViewBufferIndex = require( '@stdlib/strided/base/min-view-buffer-index' );
-var offsetView = require( '@stdlib/strided/base/offset-view' );
-var addon = require( './sasum.native.js' );
+var addon = require( './../src/addon.node' );
 
 
 // MAIN //
@@ -33,7 +31,7 @@ var addon = require( './sasum.native.js' );
 * @param {PositiveInteger} N - number of indexed elements
 * @param {Float32Array} x - input array
 * @param {integer} stride - `x` stride length
-* @param {NonNegativeInteger} offset - starting `x` index
+* @param {NonNegativeInteger} offset - starting index for `x`
 * @returns {number} sum
 *
 * @example
@@ -45,13 +43,7 @@ var addon = require( './sasum.native.js' );
 * // returns 15.0
 */
 function sasum( N, x, stride, offset ) {
-	var view;
-	offset = minViewBufferIndex( N, stride, offset );
-	if ( stride < 0 ) {
-		stride *= -1;
-	}
-	view = offsetView( x, offset );
-	return addon( N, view, stride );
+	return addon.ndarray( N, x, stride, offset );
 }
 
 

lib/node_modules/@stdlib/blas/base/sasum/lib/sasum.js

@@ -20,8 +20,8 @@
 
 // MODULES //
 
-var absf = require( '@stdlib/math/base/special/absf' );
-var float64ToFloat32 = require( '@stdlib/number/float64/base/to-float32' );
+var stride2offset = require( '@stdlib/strided/base/stride2offset' );
+var ndarray = require( './ndarray.js' );
 
 
 // MAIN //
@@ -31,7 +31,7 @@ var float64ToFloat32 = require( '@stdlib/number/float64/base/to-float32' );
 *
 * @param {PositiveInteger} N - number of indexed elements
 * @param {Float32Array} x - input array
-* @param {PositiveInteger} stride - `x` stride length
+* @param {integer} stride - `x` stride length
 * @returns {number} sum
 *
 * @example
@@ -43,18 +43,8 @@ var float64ToFloat32 = require( '@stdlib/number/float64/base/to-float32' );
 * // returns 15.0
 */
 function sasum( N, x, stride ) {
-	var sum;
-	var i;
-
-	sum = 0.0;
-	if ( N <= 0 || stride <= 0 ) {
-		return sum;
-	}
-	N *= stride;
-	for ( i = 0; i < N; i += stride ) {
-		sum = float64ToFloat32( sum + absf( x[i] ) );
-	}
-	return sum;
+	var ox = stride2offset( N, stride );
+	return ndarray( N, x, stride, ox );
 }
 
 

lib/node_modules/@stdlib/blas/base/sasum/lib/sasum.native.js

@@ -30,7 +30,7 @@ var addon = require( './../src/addon.node' );
 *
 * @param {PositiveInteger} N - number of indexed elements
 * @param {Float32Array} x - input array
-* @param {PositiveInteger} stride - `x` stride length
+* @param {integer} stride - `x` stride length
 * @returns {number} sum
 *
 * @example