This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH] Avoid extending lifetime of likely spilled hard regs in ifcvt before reload (PR rtl-optimization/56484)
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: gcc-patches at gcc dot gnu dot org, Uros Bizjak <ubizjak at gmail dot com>
- Date: Tue, 05 Mar 2013 18:28:13 +0100
- Subject: Re: [PATCH] Avoid extending lifetime of likely spilled hard regs in ifcvt before reload (PR rtl-optimization/56484)
- References: <20130305162646.GJ12913@tucnak.redhat.com>
> Without this patch, ifcvt extends lifetime of %eax hard register,
> which causes reload/LRA ICE later on. Combiner and other passes try hard
> not to do that, even ifcvt has code for it if x is a hard register a few
> lines below it, but in this case the hard register is SET_SRC (set_b).
>
> With this patch we just use the pseudo (x) which has been initialized
> from the hard register before the conditional.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> 2013-03-05 Jakub Jelinek <jakub@redhat.com>
>
> PR rtl-optimization/56484
> * ifcvt.c (noce_process_if_block): Before reload if else_bb
> is NULL, avoid extending lifetimes of hard registers in
> likely to spilled or small register classes.
ifcvt.c tests only small_register_classes_for_mode_p in the other places, so
do you really need class_likely_spilled_p here?
--
Eric Botcazou