Hi,
case of strings could also use some optimization
does it still call fpc_ansistr_compare_equal ?
fpc could hash the strings, or build a trie, even testing the length
first would help
Cheers,
Benito
Am 03.08.2018 um 21:57 schrieb J. Gareth Moreton:
Hi everyone,
So I'm pondering about attempting to implement the binary search system I
devised for case blocks. To find the correct case label, you need to
iterate a search loop a fixed maximum of ceil(log2(n)) times, where n is
the number of individual case values (excluding "else"). Given that this
is quite a low number and I managed to get the loop itself down to just 8
instructions (not including the comparison and conditional jump at the
end), this could be unwrapped for low values of ceil(log2(n))... possibly
up to 7 or 8, I'd say. However, if an exact match is found early, how
serious is the penalty of having a conditional jump forward on each
unrolled iteration for x86-64, whether it's taken or not? (This would be
the equivalent of a Break command)
Gareth aka. Kit
_______________________________________________
fpc-devel maillist - fpc-devel@lists.freepascal.org
http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
_______________________________________________
fpc-devel maillist - fpc-devel@lists.freepascal.org
http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
