Help with define_insn and constraints

[Dave Korn]

> -----Original Message-----
> From: Richard Henderson 
> Sent: 23 December 2004 23:00
> To: Ian Lance Taylor
> Cc: Dave Korn; 'Robert Baruch'; gcc
> Subject: Re: Help with define_insn and constraints
> 
> On Thu, Dec 23, 2004 at 04:37:40PM -0500, Ian Lance Taylor wrote:
> > >  ?? In your first post, you said you had 19 hard regs.  
> Does this not imply
> > > you're trying to keep your frame pointer in a pseudo ??
> > 
> > In gcc, it's normal for the frame pointer to be a pseudo which is
> > eliminated to the stack pointer, or, in the case of a function which
> > calls alloca, to be eliminated to some hard register which serves as
> > the so-called hard frame pointer.  See FRAME_POINTER_REGNUM and
> > HARD_FRAME_POINTER_REGNUM.
> 
> No.  The frame pointer is *never* a pseudo.  Sometimes a fake
> hard register, but never a pseudo.
> 
> 
> r~


  So perhaps reload is trying to find a hard reg to assign to the frame pointer,
and in order to do so it has to spill some other hard reg on the stack, and
before it can do that it has to assign a hard reg to the frame pointer, so ....
?


    cheers, 
      DaveK
-- 
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