comment on

On my laptop, the following shaves 4 seconds from one-time stringification per key.

# Return the list of dead cells surrounding a cell
sub get_dead_cells {
   my ( $cells, $x0, $y0 ) = ( shift->{Cells}, @_ );
   my ( $x1, $x2, $y1, $y2 ) = ( $x0 - 1, $x0 + 1, $y0 - 1, $y0 + 1 );
   my ( $k1, $k2, $k3, $k4, $k5, $k6, $k7, $k8 );

   ( ( $k1 = "$x1:$y1" ) x !( 0 + exists $cells->{ $k1 } ),
     ( $k2 = "$x1:$y0" ) x !( 0 + exists $cells->{ $k2 } ),
     ( $k3 = "$x1:$y2" ) x !( 0 + exists $cells->{ $k3 } ),
     ( $k4 = "$x0:$y1" ) x !( 0 + exists $cells->{ $k4 } ),
     ( $k5 = "$x0:$y2" ) x !( 0 + exists $cells->{ $k5 } ),
     ( $k6 = "$x2:$y1" ) x !( 0 + exists $cells->{ $k6 } ),
     ( $k7 = "$x2:$y0" ) x !( 0 + exists $cells->{ $k7 } ),
     ( $k8 = "$x2:$y2" ) x !( 0 + exists $cells->{ $k8 } ) );
}
[download]

To not allocate the key variables each time, another 2 seconds reduction is possible with the state feature.

use feature 'state';

# Return the list of dead cells surrounding a cell
sub get_dead_cells {
   my ( $cells, $x0, $y0 ) = ( shift->{Cells}, @_ );
   my ( $x1, $x2, $y1, $y2 ) = ( $x0 - 1, $x0 + 1, $y0 - 1, $y0 + 1 );

   state ( $k1, $k2, $k3, $k4, $k5, $k6, $k7, $k8 );

   ( ( $k1 = "$x1:$y1" ) x !( 0 + exists $cells->{ $k1 } ),
     ( $k2 = "$x1:$y0" ) x !( 0 + exists $cells->{ $k2 } ),
     ( $k3 = "$x1:$y2" ) x !( 0 + exists $cells->{ $k3 } ),
     ( $k4 = "$x0:$y1" ) x !( 0 + exists $cells->{ $k4 } ),
     ( $k5 = "$x0:$y2" ) x !( 0 + exists $cells->{ $k5 } ),
     ( $k6 = "$x2:$y1" ) x !( 0 + exists $cells->{ $k6 } ),
     ( $k7 = "$x2:$y0" ) x !( 0 + exists $cells->{ $k7 } ),
     ( $k8 = "$x2:$y2" ) x !( 0 + exists $cells->{ $k8 } ) );
}
[download]

Regards, Mario

In reply to Re^3: High Performance Game of Life by marioroy
in thread High Performance Game of Life by eyepopslikeamosquito

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