Re: Arg pointer and SSE code

[Jan Hubicka <jh at suse dot cz>]

> On Wed, Feb 21, 2001 at 08:52:20PM +0100, Jan Hubicka wrote:
> > Enabling -msse makes gcc to always use register 4 for arg pointer
> > (if I am not mistaken) independently whether TImodes are used or not.
> 
> Yes, this is a major problem.
What can be really sweet is chance to have arg pointer as pseudo - so we will
do spilling.
Even if register 4 is used only for functions using TImodes and SSE, we will run
into trouble with ASM inlines that generally wants all registers.

We need the argument pointer usually just shortly in the prologue and then
in epilogue.  In rest of code it can be hapilly spilled.
> 
> > Question remains, how to determine if we need the alignment code. 
> 
> cfun->stack_alignment_needed?  That might change through
:) I've introduced it for such purposes..
> different rounds of reload, as TImode values get spilled,
> but elimination is prepared for that sort of thing.
Really? That sounds like good news for me.
Why we don't use it for the PIC pointer then as well?

Honza
> 
> 
> r~