This is the mail archive of the
gcc-help@gcc.gnu.org
mailing list for the GCC project.
Re: Compiling gcc in 64 bits mode
- From: kevin diggs <diggskevin38 at gmail dot com>
- To: Jeremy Hall <gcc dot hall at gmail dot com>
- Cc: gcc-help at gcc dot gnu dot org
- Date: Mon, 1 Aug 2011 13:23:01 -0500
- Subject: Re: Compiling gcc in 64 bits mode
- References: <CADJRTM3CkB0QPj33e+ZBR1C4Kt6HRemQ=J9WoMBLj66iOrn0Zg@mail.gmail.com>
Hi,
On Sat, Jul 30, 2011 at 3:48 AM, Jeremy Hall <gcc.hall@gmail.com> 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