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Re: "=rXX" asm constraints on powerpc?
- From: Marcus Brinkmann <Marcus dot Brinkmann at ruhr-uni-bochum dot de>
- To: gcc-help at gnu dot org
- Date: Mon, 22 Sep 2003 19:27:48 +0200
- Subject: Re: "=rXX" asm constraints on powerpc?
- References: <20030922161348.GD627@212.23.136.22>
On Mon, Sep 22, 2003 at 06:13:48PM +0200, Marcus Brinkmann wrote:
> I want to implement system call stubs on PPC. The code I want to end up
> this is the following ("tlbia" is really used as a slow system call here,
> that returns a pointer and three ints in r3 to r6):
I might just have misunderstood the wording in the gcc manual. It seemed to
me that gcc doesn't guarantee me that a register I allocate for a local
variable is really used for that variable. But the manual only says that it
is not tied to that variable _at all times_. At some times, and I assume
now that at all times it matters to me (in the asm statement), it will be
tied to that variable.
In that circumstances, I can do what I want to do with local vars in the
right registers, without explicit mr instructions.
Thanks,
Marcus
--
`Rhubarb is no Egyptian god.' GNU http://www.gnu.org marcus@gnu.org
Marcus Brinkmann The Hurd http://www.gnu.org/software/hurd/
Marcus.Brinkmann@ruhr-uni-bochum.de
http://www.marcus-brinkmann.de/