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Re: x86-64 and large code model questions/bugs
- From: Andi Kleen <andi at firstfloor dot org>
- To: sje at cup dot hp dot com
- Cc: gcc at gcc dot gnu dot org
- Date: Tue, 27 Jan 2009 12:31:07 +0100
- Subject: Re: x86-64 and large code model questions/bugs
- References: <200901262226.n0QMQK824731@evrst7.cup.hp.com>
Steve Ellcey <sje@cup.hp.com> writes:
> The first one is: would it be reasonable to compile crt files with
> -mcmodel=large by default on the x86-64 linux platform? Currently the
> crt files are not compiled with this option and that makes it impossible
> to compile a program where the text segment is above 4GB (for example)
Over 2GB.
> because the crt files can't handle the large code model if they aren't
> compiled with this option.
My understanding is that this would likely break old linkers which
didn't do all large model relocations correctly. Right now they
work as long as you don't need the large model.
BTW the standard way to work around large model issues if your
code isn't really that large but you just want to move it is to move
parts of the programs into a .so and compile -fPIC. large is only
really needed if you really have gigantic programs (but then gcc
tends to be also quite slow on them)
-Andi
--
ak@linux.intel.com -- Speaking for myself only.