[Mesa-dev] [PATCH 4/9] i965: Compact acc_wr_control only on Gen6+.

[Iago Toral]

On Tue, 2015-10-20 at 10:51 +0200, Iago Toral wrote:
> On Mon, 2015-10-19 at 21:09 -0700, Matt Turner wrote:
> > It only exists on Gen6+, and the next patches will add compaction
> > support for the (unused) field in the same location on earlier
> > platforms.
> 
> The docs say that this exists also in ILK at least. See Page 131 of:
> https://01.org/sites/default/files/documentation/ilk_ihd_os_vol4_part2_july_28_10_0.pdf

Also, there is mention to compaction of this field in the same ILK doc,
in page 101.

> However, I see some places in the i965 code where dealing with this is
> surrounded by if (gen >= 6)... 
> 
> Is this a bug in the ILK documentation?
> 
> Iago
> 
> > ---
> >  src/mesa/drivers/dri/i965/brw_eu_compact.c | 10 ++++++++--
> >  1 file changed, 8 insertions(+), 2 deletions(-)
> > 
> > diff --git a/src/mesa/drivers/dri/i965/brw_eu_compact.c b/src/mesa/drivers/dri/i965/brw_eu_compact.c
> > index facf3cd..b122dec 100644
> > --- a/src/mesa/drivers/dri/i965/brw_eu_compact.c
> > +++ b/src/mesa/drivers/dri/i965/brw_eu_compact.c
> > @@ -1016,7 +1016,10 @@ brw_try_compact_instruction(const struct brw_device_info *devinfo,
> >     if (!set_subreg_index(devinfo, &temp, src, is_immediate))
> >        return false;
> >  
> > -   compact(acc_wr_control);
> > +   if (devinfo->gen >= 6) {
> > +      compact(acc_wr_control);
> > +   }
> > +
> >     compact(cond_modifier);
> >  
> >     if (devinfo->gen <= 6)
> > @@ -1224,7 +1227,10 @@ brw_uncompact_instruction(const struct brw_device_info *devinfo, brw_inst *dst,
> >  
> >     set_uncompacted_subreg(devinfo, dst, src);
> >  
> > -   uncompact(acc_wr_control);
> > +   if (devinfo->gen >= 6) {
> > +      uncompact(acc_wr_control);
> > +   }
> > +
> >     uncompact(cond_modifier);
> >  
> >     if (devinfo->gen <= 6)
>