[Bug target/34091] [4.2/4.3 Regression] ICE in reload_cse_simplify_operands, at postreload.c:392

["dave at hiauly1 dot hia dot nrc dot ca" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #12 from dave at hiauly1 dot hia dot nrc dot ca  2007-11-24 22:14 -------
Subject: Re:  [4.2/4.3 Regression] ICE in reload_cse_simplify_operands, at
postreload.c:392

> > I haven't seen the paradoxical subreg in a float/fix conversion
> > insns with the current patch.  I did see this in some of the first
> > versions of pa_cannot_change_mode_class.  I think I eliminated
> > this problem by prevent mode changes in the FP registers:
> > 
> >   if (MAYBE_FP_REG_CLASS_P (class))
> >       return true;
> > 
> > Due you think this problem is latent?
> 
> On SPARC or on the PA even with CANNOT_CHANGE_MODE_CLASS?

I meant on the PA using the CANNOT_CHANGE_MODE_CLASS patch.

What I saw when mode changes were allowed was something like
the following:

set (subreg:SI (mem:HI)) (fix:SI (fix:SF))

where the mem was a spilled HImode pseudo.  At the time,
I thought I had stopped mode changes to QImode/HImode in
the FPU registers but I believe they got tied to DImode.

Dave


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34091