bench: refactor benchmarks

Author: kgryte

lib/node_modules/@stdlib/math/base/special/erf/benchmark/c/benchmark.c

@@ -89,16 +89,18 @@ static double rand_double( void ) {
 * @return elapsed time in seconds
 */
 static double benchmark( void ) {
+	double values[ 10 ];
 	double elapsed;
-	double x;
 	double y;
 	double t;
 	int i;
 
+	for ( i = 0; i < 10; i++ ) {
+		values[ i ] = ( 2.0*rand_double() ) - 1.0;
+	}
 	t = tic();
 	for ( i = 0; i < ITERATIONS; i++ ) {
-		x = ( 2.0*rand_double() ) - 1.0;
-		y = erf( x );
+		y = erf( values[ i%10 ] );
 		if ( y != y ) {
 			printf( "should not return NaN\n" );
 			break;

lib/node_modules/@stdlib/math/base/special/erf/benchmark/c/cephes/benchmark.c

@@ -94,16 +94,18 @@ static double rand_double( void ) {
 * @return elapsed time in seconds
 */
 static double benchmark( void ) {
+	double values[ 10 ];
 	double elapsed;
-	double x;
 	double y;
 	double t;
 	int i;
 
+	for ( i = 0; i < 10; i++ ) {
+		values[ i ] = ( 2.0*rand_double() ) - 1.0;
+	}
 	t = tic();
 	for ( i = 0; i < ITERATIONS; i++ ) {
-		x = ( 2.0*rand_double() ) - 1.0;
-		y = erf( x );
+		y = erf( values[ i%10 ] );
 		if ( y != y ) {
 			printf( "should not return NaN\n" );
 			break;

lib/node_modules/@stdlib/math/base/special/erf/benchmark/c/native/benchmark.c

@@ -90,16 +90,18 @@ static double rand_double( void ) {
 * @return elapsed time in seconds
 */
 static double benchmark( void ) {
+	double values[ 10 ];
 	double elapsed;
-	double x;
 	double y;
 	double t;
 	int i;
 
+	for ( i = 0; i < 10; i++ ) {
+		values[ i ] = ( 2.0*rand_double() ) - 1.0;
+	}
 	t = tic();
 	for ( i = 0; i < ITERATIONS; i++ ) {
-		x = ( 2.0*rand_double() ) - 1.0;
-		y = stdlib_base_erf( x );
+		y = stdlib_base_erf( values[ i%10 ] );
 		if ( y != y ) {
 			printf( "should not return NaN\n" );
 			break;