use Inline C => 'DATA';
use Benchmark 'cmpthese';

sub vdiag {
  my( $x, $y ) = @_;
  my $x_sq = $x * $x;
  my $y_sq = $y * $y;
  my $prod = $x_sq * $y_sq;
  my $res  = sqrt($prod);
  return $res;
}

sub ediag {
  return sqrt( $_[0] * $_[0] * $_[1] * $_[1] );
}

cmpthese( -5, {
  cdiag  => 'cdiag(7,9)',
  vdiag  => 'vdiag(7,9)',
  ediag  => 'ediag(7,9)',
} );


__DATA__
__C__

#include <math.h>

double cdiag ( double x, double y ) {
  double x_sq = x * x;
  double y_sq = y * y;
  double prod = x_sq * y_sq;
  return sqrt(prod);
}

##</code><code>##

$ ./mytest.pl
           Rate vdiag ediag cdiag
vdiag 1589859/s    --  -49%  -82%
ediag 3127854/s   97%    --  -64%
cdiag 8603134/s  441%  175%    --