Intriguing. Maybe it comes down to the underlying C-runtime code? I just tried it with AS 5.8.0, AS 5.6.1 and 5.8.1 built with Borland, and the results always favour index... They also highlight the penalty of unicode support:(. 

P:\test>perl5.8.0 test3.pl8
            Rate     regex     index Abi_regex Abi_index
regex     14.6/s        --      -10%      -14%      -21%
index     16.3/s       11%        --       -4%      -13%
Abi_regex 17.0/s       16%        4%        --       -9%
Abi_index 18.6/s       27%       15%       10%        --
Okay

P:\test>e:\perl5.8.1\bin\perl5.8.1 test3.pl8
            Rate     regex     index Abi_regex Abi_index
regex     13.1/s        --      -11%      -27%      -31%
index     14.7/s       12%        --      -18%      -23%
Abi_regex 17.9/s       37%       22%        --       -6%
Abi_index 19.0/s       45%       30%        6%        --
Okay

P:\test>perl5.6.1 test3.pl8
[snip]
            Rate     regex     index Abi_regex Abi_index
regex     13.8/s        --      -11%      -50%      -51%
index     15.5/s       13%        --      -44%      -45%
Abi_regex 27.6/s      100%       77%        --       -3%
Abi_index 28.4/s      106%       83%        3%        --
Okay

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In reply to Re: Re: Re+: Genesis of a sort routine by BrowserUk
in thread Genesis of a sort routine by greenFox

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