nir: Add a concept of per-member structs and a lowering pass

This adds a concept of "members" to a variable with an interface type.
It allows you to specify the full variable data for each member of the
interface instead of once for the variable.  We also add a lowering pass
to lower those variables to a sequence of variables and rewrite all the
derefs accordingly.

Acked-by: Rob Clark <[email protected]>
Acked-by: Bas Nieuwenhuizen <[email protected]>
Acked-by: Dave Airlie <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/compiler/nir/nir_clone.c b/src/compiler/nir/nir_clone.c
index 7236f0872a7..76121d05a7e 100644
--- a/src/compiler/nir/nir_clone.c
+++ b/src/compiler/nir/nir_clone.c
@@ -161,6 +161,14 @@ nir_variable_clone(const nir_variable *var, nir_shader *shader)
    }
    nvar->interface_type = var->interface_type;
 
+   nvar->num_members = var->num_members;
+   if (var->num_members) {
+      nvar->members = ralloc_array(nvar, struct nir_variable_data,
+                                   var->num_members);
+      memcpy(nvar->members, var->members,
+             var->num_members * sizeof(*var->members));
+   }
+
    return nvar;
 }