Re: Load hoisting bug

[Richard Henderson <rth at redhat dot com>]

On Fri, Dec 07, 2001 at 05:16:28PM -0700, law@redhat.com wrote:
>   > 	We have not had enough fun with loop optimizations lately, so I
>   > found one...
>   > 
>   > 	The divconst-3.c regression on AIX which appeared at the beginning
>   > of November is due to GCC miscompiling itself.  The miscompilation is
>   > caused by a loop optimization which was not safe.
> [ ... ]
> Note that the handling of hard registers in loops changed in early November.
> I believe this is the patch:
> 
>         * loop.c (loop_regs_scan):  Don't invalidate PIC register.
> 
> You might try without that patch and see if this problem goes away.

It will go away.  The problem is almost certainly the DImode.
There's a missing HARD_REGNO_NREGS somewhere in the loop code.


r~