You did only do the unpack to an array once--not every time you needed a number--didn't you?

If that is the case, I'd benchmark combining substr and unpack against the other options: 

my $str = ...;

sub fetchOne{ unpack 'a4', substr $str, $_[ 0 ] * 4, 4 }

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In reply to Re^3: Null-stripping performance by BrowserUk
in thread Null-stripping performance by qiau

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