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I didn't know that! Is the logic behind replacing the sub with a string expression, to fool the cache?

use Benchmark 'cmpthese'; cmpthese(-2, { predecl => ' my $y; my $x; for $x (1..10000) { $y+=$x } ', lexical => ' my $y; for my $x (1..10000) { $y+=$x } ', }); __END__
Rate lexical predecl lexical 3996/s -- -0% predecl 4001/s 0% --

vs

use Benchmark 'cmpthese'; cmpthese(-2, { predecl => sub { my $y; my $x; for $x (1..10000) { $y+=$x } }, lexical => sub { my $y; for my $x (1..10000) { $y+=$x } }, });
Rate predecl lexical predecl 4011/s -- -0% lexical 4015/s 0% --

Which is more or less what haukex and choroba demonstrated.


In reply to Re^3: declaring lexical variables in shortest scope: performance? by bliako
in thread declaring lexical variables in shortest scope: performance? by bliako

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