On Sat, Dec 27, 2003 at 06:17:34PM -0500, Dan Sugalski wrote: > Also, you might want to make sure you've built Parrot with > optimizations on. By default we don't enable GCC's -O to do any > optimization, and that does slow things down a bunch. On the other > hand, it makes debugging a whole lot easier. Perl 5 is built with > full optimization, so that'll make quite a difference. (Pass the > --optimize flag to Configure.pl to enable it, and expect the core ops > files to chew massive amounts of RAM and swap while it happens)
For benchmarking with gcc 3.x on x86 I'm tending to use -O2 -falign-loops=16 -falign-jumps=16 -falign-functions=16 -falign-labels=16 -mpreferred-stack-boundary=4 -minline-all-stringops to disable the default code placement options, which as far as I can tell from the documentation chose whether to pad code to better alignments based on the amount of padding that would be needed. These defaults mean that changing the size of earlier parts of the object file can affect the alignment (and hence speed) of loops you didn't change. This is very confusing. Nicholas Clark
