On Fri, May 13, 2011 at 9:54 AM, cobines <cobi...@gmail.com> wrote: > 2011/5/13 Ben <ben.smith.li...@gmail.com>: >> On 12/05/2011 20:54, cobines wrote: >>> >>> I'm running it on Windows XP i386, compiled with FPC 2.5.1 17430. >>> >> >> >> I tried this on my system which runs 64-bit Linux with FPC 2.4.3 (64-bit). >> >> Using -O, -O2 or -O3 command line parameters. In each case, the >> generated executable runs exactly the same. They actually have the exact >> same result: 828ms >> >> So here, with or without "optimization", it makes zero difference. Which >> is weird in it's own way. > > On x86_64 it seems MMX instructions are used with or without > optimizations enabled. Those instructions can operate on memory as > well as on registers so there is no additional step where registers > are written to memory. > > So I tried with "fpc -OpPENTIUM ..." but MMX instructions are not > generated anyway for i386. > > I tried on Linux i386 and have the same thing, so this is only on i386 I > think.
So, not to use the option -O in i386? When I compile FPC sources, on Win32 XP SP3, using make, the option is used. I'm confusing now... Marcos Douglas _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
