[Mesa-dev] [PATCH] glsl: Make sure that packed varyings reflect always_active_io properly.

[Eric Anholt]

The always_active_io flag was only set according to the first variable
that got packed in, so NIR io compaction would end up compacting XFB
varyings that shouldn't move at that point.
---

This doesn't fix my XFB issues on V3D, but seems like a step in the
right direction.  Packing always_active_io variables with
non-always_active_io variables seems questionable to me, though.

 src/compiler/glsl/lower_packed_varyings.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/compiler/glsl/lower_packed_varyings.cpp b/src/compiler/glsl/lower_packed_varyings.cpp
index 5c1eed719f26..5bd6c92ed992 100644
--- a/src/compiler/glsl/lower_packed_varyings.cpp
+++ b/src/compiler/glsl/lower_packed_varyings.cpp
@@ -729,12 +729,17 @@ lower_packed_varyings_visitor::get_packed_varying_deref(
       unpacked_var->insert_before(packed_var);
       this->packed_varyings[slot] = packed_var;
    } else {
+      ir_variable *var = this->packed_varyings[slot];
+
+      /* The slot needs to be marked as always active if any variable that got
+       * packed there was.
+       */
+      var->data.always_active_io |= unpacked_var->data.always_active_io;
+
       /* For geometry shader inputs, only update the packed variable name the
        * first time we visit each component.
        */
       if (this->gs_input_vertices == 0 || vertex_index == 0) {
-         ir_variable *var = this->packed_varyings[slot];
-
          if (var->is_name_ralloced())
             ralloc_asprintf_append((char **) &var->name, ",%s", name);
          else
-- 
2.18.0.rc2