From: Ian Lance Taylor <iant@google.com>
To: Daniel Mierswa <impulze@impulze.org>
Cc: gcc-help@gcc.gnu.org
Subject: Re: Inline ASM and stack/base pointer
Date: Thu, 09 Jun 2011 18:09:00 -0000 [thread overview]
Message-ID: <mcrr5723nfg.fsf@coign.corp.google.com> (raw)
In-Reply-To: <4DF0F706.5050803@impulze.org> (Daniel Mierswa's message of "Thu, 09 Jun 2011 16:38:30 +0000")
Daniel Mierswa <impulze@impulze.org> writes:
> I was wondering how to overcome the issue that evolves when parameters
> (inputs) to the inline assembly are passed relative to ebp/esp and
> modifying those pointers in the inline assembly. Basically
> __asm__("push %ecx\nmov %0, %edx\n"::"m"(variable)); could set '%0' to
> 4(%esp) or similar which would no longer represent the same location
> once I use push/pop in my asm. Is it possible to explicitly state that
> GCC passes those relative to esp _or_ ebp so I can safely modify at
> least one pointer (i.e. reserve stack space)? Or are there any other
> ways to overcome this issue? Thanks in advance.
Add "%esp" to your clobber list. That should force the compiler to pass
any stack variables using an offset from %ebp.
Ian
next prev parent reply other threads:[~2011-06-09 17:49 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-09 15:22 Daniel Mierswa
2011-06-09 18:09 ` Ian Lance Taylor [this message]
2011-06-09 18:47 ` kevin diggs
2011-06-09 19:53 ` Ian Lance Taylor
2011-06-09 20:26 ` Daniel Mierswa
2011-06-09 20:41 ` Daniel Mierswa
[not found] ` <BANLkTikg+N_E=OYU-wU2Od=2rsh=K=Ktsg@mail.gmail.com>
2011-06-09 23:12 ` Daniel Mierswa
2011-06-10 1:21 ` Ian Lance Taylor
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