Looking at the docs a bit, it looks like we should never have been using predicate_normal for if's in the first place
Reviewed-by: Jason Ekstrand <jason.ekstr...@intel.com> On Sat, Oct 10, 2015 at 4:24 AM, Alejandro Piñeiro <apinhe...@igalia.com> wrote: > --- > > I already talked about this with Jason Ekstrand and Matt Turner > privately, but just in case somebody else jump to the review: > > When using BRW_PREDICATE_NORMAL, the if will use all the channels of > the register flag. But nir_if only reads from one channel, so that > is not needed. Another hint showing that this is safe: the MOV that > put the condition on f0 is calling get_nir_src with just one > component. That will return always a source with swizzle > BRW_SWIZZLE_XXXX, so that component is the only to be used. > > This commit is not needed/solving anything per-se, but it is needed in > order to be able to implement vec4_cmod_propagation with a good > overall outcome. > > src/mesa/drivers/dri/i965/brw_vec4_nir.cpp | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp > b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp > index 41bd80d..e05745f 100644 > --- a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp > +++ b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp > @@ -193,7 +193,9 @@ vec4_visitor::nir_emit_if(nir_if *if_stmt) > vec4_instruction *inst = emit(MOV(dst_null_d(), condition)); > inst->conditional_mod = BRW_CONDITIONAL_NZ; > > - emit(IF(BRW_PREDICATE_NORMAL)); > + /* We can just predicate based on the X channel, as the condition only > + * reads from one channel */ > + emit(IF(BRW_PREDICATE_ALIGN16_REPLICATE_X)); > > nir_emit_cf_list(&if_stmt->then_list); > > -- > 2.1.4 > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
