Re: [Qemu-devel] [PATCH] target-xtensa: de-optimize EXTUI

[Aurelien Jarno <aurelien@aurel32.net>]

On Wed, Sep 26, 2012 at 03:05:18AM +0400, Max Filippov wrote:
> On Wed, Sep 26, 2012 at 2:57 AM, Aurelien Jarno <aurelien@aurel32.net> wrote:
> > Now that and with 0xff, 0xffff and 0xffffffff is optimized in
> > tcg/tcg-op.h, there is no need to do it in target-xtensa/translate.c.
> >
> > Cc: Max Filippov <jcmvbkbc@gmail.com>
> > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> > ---
> >  target-xtensa/translate.c |   15 +--------------
> >  1 file changed, 1 insertion(+), 14 deletions(-)
> >
> > diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
> > index ba3ffcb..c1358ee 100644
> > --- a/target-xtensa/translate.c
> > +++ b/target-xtensa/translate.c
> > @@ -1835,20 +1835,7 @@ static void disas_xtensa_insn(DisasContext *dc)
> >                  } else {
> >                      tcg_gen_mov_i32(tmp, cpu_R[RRR_T]);
> >                  }
> 
> I guess shri above may be de-optimized as well.
> In any case Acked-by: Max Filippov <jcmvbkbc@gmail.com>

Good catch, I looked for some patterns in the targets code, and didn't
see this one. I'll send an updated patch.

> > -
> > -                switch (maskimm) {
> > -                case 0xff:
> > -                    tcg_gen_ext8u_i32(cpu_R[RRR_R], tmp);
> > -                    break;
> > -
> > -                case 0xffff:
> > -                    tcg_gen_ext16u_i32(cpu_R[RRR_R], tmp);
> > -                    break;
> > -
> > -                default:
> > -                    tcg_gen_andi_i32(cpu_R[RRR_R], tmp, maskimm);
> > -                    break;
> > -                }
> > +                tcg_gen_andi_i32(cpu_R[RRR_R], tmp, maskimm);
> >                  tcg_temp_free(tmp);
> >              }
> >              break;
> > --
> > 1.7.10.4
> >
> >
> 
> -- 
> Thanks.
> -- Max
> 
> 

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net