Jonas Maebe wrote:
On 10 dec 2005, at 22:09, darekM wrote:
I've see that reverse-complement benchmark <http://
shootout.alioth.debian.org/benchmark.php?test=revcomp&lang=all> for
FPC is very slow. I discover, that problem is with readln, that
function consume about 90% of time.
In my test (Mac OS X/PPC, rtl and program compiled with register
variables, text buffer of 64kb) readln's overheid is negligible. The
large cost comes from writeln. The reason the C version is so much
faster is because its output is buffered as well. We automatically
flush the output after each writeln (i.e. after each writeln of 60
characters), while in C this only happens at the very end of the
program for 128kb of characters at a time.
Another speed improvement will be disabling IO checks for write, {$I-}
I normally wouldn't recomend doing so, but for this test it either
passes or fails.
Marc
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