bench: refactor to use dynamic memory allocation in blas/base/drotm

PR-URL: #9088
Ref: #8643
Reviewed-by: Athan Reines <kgryte@gmail.com>

Author: officiallyanee

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

@@ -96,12 +96,14 @@ static double rand_double( void ) {
 */
 static double benchmark1( int iterations, int len ) {
 	double elapsed;
-	double x[ len ];
-	double y[ len ];
+	double *x;
+	double *y;
 	double t;
 	int i;
 
 	const double param[5] = { 0.0, 0.0, 0.0, 0.0, 0.0 };
+	x = (double *) malloc( len * sizeof( double ) );
+	y = (double *) malloc( len * sizeof( double ) );
 	for ( i = 0; i < len; i++ ) {
 		x[ i ] = ( rand_double()*200.0 ) - 100.0;
 		y[ i ] = ( rand_double()*200.0 ) - 100.0;
@@ -119,6 +121,8 @@ static double benchmark1( int iterations, int len ) {
 	if ( y[ 0 ] != y[ 0 ] ) {
 		printf( "should not return NaN\n" );
 	}
+	free( x );
+	free( y );
 	return elapsed;
 }
 
@@ -131,12 +135,14 @@ static double benchmark1( int iterations, int len ) {
 */
 static double benchmark2( int iterations, int len ) {
 	double elapsed;
-	double x[ len ];
-	double y[ len ];
+	double *x;
+	double *y;
 	double t;
 	int i;
 
 	const double param[5] = { 0.0, 0.0, 0.0, 0.0, 0.0 };
+	x = (double *) malloc( len * sizeof( double ) );
+	y = (double *) malloc( len * sizeof( double ) );
 	for ( i = 0; i < len; i++ ) {
 		x[ i ] = ( rand_double()*200.0 ) - 100.0;
 		y[ i ] = ( rand_double()*200.0 ) - 100.0;
@@ -154,6 +160,8 @@ static double benchmark2( int iterations, int len ) {
 	if ( y[ 0 ] != y[ 0 ] ) {
 		printf( "should not return NaN\n" );
 	}
+	free( x );
+	free( y );
 	return elapsed;
 }