Hi, On Sat, Jul 30, 2011 at 3:48 AM, Jeremy Hall <gcc.hall@xxxxxxxxx> wrote: >> I don't have any x86-64 (int64) systems. Is it better to use 64-bit on >> x86-64 even with the larger memory footprint (because the programming >> model is better (more registers, etc))? > > I'd say yes. As you suggest, there is more to x64 than the memory > footprint. There are there are twice as many general purpose > registers amongst other things. So for example more function > arguments are passed in registers than on the stack. > > Here are some figures for a small program compiled identically on both > 32 and 64 bits. > > 32 bit code > Insns 15506, Jumps 3218, Mem refs 3819, Stack refs 1671 > 64 bit code > Insns 14631, Jumps 3158, Mem refs 3142, Stack refs 1042 > > The 64 bit executable was only about 10% larger. > > Jeremy > I was actually referring to the runtime size (data segment). I've never actually tried to build a PPC 64-bit Firefox (i.e. I have a 64-bit PPC box). I'd like to see the data size usage compared to 32-bit. kevin
