This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH]: HC11 regression, don't rely on REG_WAS_0 notes
- From: Kazu Hirata <kazu at cs dot umass dot edu>
- To: stcarrez at nerim dot fr
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Mon, 31 Mar 2003 16:34:03 -0500 (EST)
- Subject: Re: [PATCH]: HC11 regression, don't rely on REG_WAS_0 notes
- References: <3E88A996.7010401@nerim.fr>
Hi Stephane,
> I was too optimistic in thinking the REG_WAS_0 notes could be used.
> They can in some cases. But they are not removed in other cases and
> this results in wrong value to be set (reg is
> incremented/decremented instead of loading +1/-1 in it, but since
> the previous reg value is *not* 0, we get a wrong value).
Can you achieve the same with move2add in reload1.c? As long as you
define costs correctly, you'll benefit from the move2add optimization.
Kazu Hirata