glsl: Pack integer and double varyings as flat even if interpolation mode is none

v2: Also update varying_matches::compute_packing_class().  Suggested by
Timothy Arceri.

Signed-off-by: Ian Romanick <[email protected]>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96358
Reviewed-by: Kenneth Graunke <[email protected]>
Cc: "12.0" <[email protected]>
Cc: Gregory Hainaut <[email protected]>
Cc: Ilia Mirkin <[email protected]>

3 files changed, 15 insertions, 6 deletions

diff --git a/src/compiler/glsl/ir.h b/src/compiler/glsl/ir.h
index cd56a2a9f52..1325e3533fe 100644
--- a/src/compiler/glsl/ir.h
+++ b/src/compiler/glsl/ir.h
@@ -590,6 +590,13 @@ public:
       return this->u.state_slots;
    }
 
+   inline bool is_interpolation_flat() const
+   {
+      return this->data.interpolation == INTERP_QUALIFIER_FLAT ||
+             this->type->contains_integer() ||
+             this->type->contains_double();
+   }
+
    inline bool is_name_ralloced() const
    {
       return this->name != ir_variable::tmp_name;
diff --git a/src/compiler/glsl/link_varyings.cpp b/src/compiler/glsl/link_varyings.cpp
index 473626b7a16..76d0be1c61d 100644
--- a/src/compiler/glsl/link_varyings.cpp
+++ b/src/compiler/glsl/link_varyings.cpp
@@ -1611,7 +1611,8 @@ varying_matches::compute_packing_class(const ir_variable *var)
    unsigned packing_class = var->data.centroid | (var->data.sample << 1) |
                             (var->data.patch << 2);
    packing_class *= 4;
-   packing_class += var->data.interpolation;
+   packing_class += var->is_interpolation_flat()
+      ? unsigned(INTERP_QUALIFIER_FLAT) : var->data.interpolation;
    return packing_class;
 }
 
diff --git a/src/compiler/glsl/lower_packed_varyings.cpp b/src/compiler/glsl/lower_packed_varyings.cpp
index a897d2fb59b..2b347399cea 100644
--- a/src/compiler/glsl/lower_packed_varyings.cpp
+++ b/src/compiler/glsl/lower_packed_varyings.cpp
@@ -273,11 +273,11 @@ lower_packed_varyings_visitor::run(struct gl_linked_shader *shader)
          continue;
 
       /* This lowering pass is only capable of packing floats and ints
-       * together when their interpolation mode is "flat".  Therefore, to be
-       * safe, caller should ensure that integral varyings always use flat
-       * interpolation, even when this is not required by GLSL.
+       * together when their interpolation mode is "flat".  Treat integers as
+       * being flat when the interpolation mode is none.
        */
       assert(var->data.interpolation == INTERP_QUALIFIER_FLAT ||
+             var->data.interpolation == INTERP_QUALIFIER_NONE ||
              !var->type->contains_integer());
 
       /* Clone the variable for program resource list before
@@ -607,7 +607,7 @@ lower_packed_varyings_visitor::get_packed_varying_deref(
    if (this->packed_varyings[slot] == NULL) {
       char *packed_name = ralloc_asprintf(this->mem_ctx, "packed:%s", name);
       const glsl_type *packed_type;
-      if (unpacked_var->data.interpolation == INTERP_QUALIFIER_FLAT)
+      if (unpacked_var->is_interpolation_flat())
          packed_type = glsl_type::ivec4_type;
       else
          packed_type = glsl_type::vec4_type;
@@ -627,7 +627,8 @@ lower_packed_varyings_visitor::get_packed_varying_deref(
       packed_var->data.centroid = unpacked_var->data.centroid;
       packed_var->data.sample = unpacked_var->data.sample;
       packed_var->data.patch = unpacked_var->data.patch;
-      packed_var->data.interpolation = unpacked_var->data.interpolation;
+      packed_var->data.interpolation = packed_type == glsl_type::ivec4_type
+         ? unsigned(INTERP_QUALIFIER_FLAT) : unpacked_var->data.interpolation;
       packed_var->data.location = location;
       packed_var->data.precision = unpacked_var->data.precision;
       packed_var->data.always_active_io = unpacked_var->data.always_active_io;