Re: [rs6000] Fix ICE with -fstack-limit-register and large frames

[Segher Boessenkool <segher@kernel.crashing.org>]

On Fri, Jun 02, 2017 at 10:27:33AM +0200, Eric Botcazou wrote:
> > Could you make the expander handle it, instead?  It's as simple as (after
> > the double-reg thing) add "if operands[1] is reg 0, force_reg operands[2]".
> > I'll do it if you prefer.
> 
> Probably, because I'm not sure how this can work, as you cannot create new 
> pseudos here.

Because you cannot during reload, or another reason?  We always use LRA
on powerpc nowadays, and LRA can deal with this.

> > [ the patch is broken here ]
> 
> It applies just fine for me though.  But it could probably use add_operand 
> instead of satisfies_constraint_I in the condition.

Only the first hunk (rs6000.md) applies, the rest is ignored (there is a
blank line here instead of a diff header).

add_operand would be better, yeah.

> > > /* { dg-do compile } */
> > > /* { dg-options "-fstack-limit-register=r2" } */
> > 
> > Please use a different register, r2 already has different functions in
> > most ABIs.  It *probably* will compile anyway, but :-)
> 
> It's a straight copy of gcc.target/powerpc/pr48344-1.c though.

I see.  We'll fix it :-)


Segher