nir: Pass a type_size() function pointer into nir_lower_io().

Previously, there were four type_size() functions in play - the i965
compiler backend defined scalar and vec4 type_size() functions, and
nir_lower_io contained its own similar functions.

In fact, the i965 driver used nir_lower_io() and then looped over the
components using its own type_size - meaning both were in play.  The
two are /basically/ the same, but not exactly in obscure cases like
subroutines and images.

This patch removes nir_lower_io's functions, and instead makes the
driver supply a function pointer.  This gives the driver ultimate
flexibility in deciding how it wants to count things, reduces code
duplication, and improves consistency.

v2 (Jason Ekstrand):
 - One side-effect of passing in a function pointer is that nir_lower_io is
   now aware of and properly allocates space for image uniforms, allowing
   us to drop hacks in the backend

Signed-off-by: Kenneth Graunke <[email protected]>
Reviewed-by: Jason Ekstrand <[email protected]>
v2 Reviewed-by: Kenneth Graunke <[email protected]>

2 files changed, 11 insertions, 18 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
index 6dda299c990..b32f8a75e73 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
@@ -239,18 +239,7 @@ fs_visitor::nir_setup_uniform(nir_variable *var)
       }
 
       if (storage->type->is_image()) {
-         /* Images don't get a valid location assigned by nir_lower_io()
-          * because their size is driver-specific, so we need to allocate
-          * space for them here at the end of the parameter array.
-          */
-         var->data.driver_location = uniforms;
-         unsigned size =
-            BRW_IMAGE_PARAM_SIZE * MAX2(storage->array_elements, 1);
-
-         setup_image_uniform_values(uniforms, storage);
-
-         param_size[uniforms] = size;
-         uniforms += size;
+         setup_image_uniform_values(index, storage);
       } else {
          unsigned slots = storage->type->component_slots();
          if (storage->array_elements)
diff --git a/src/mesa/drivers/dri/i965/brw_nir.c b/src/mesa/drivers/dri/i965/brw_nir.c
index b5788fa2e33..3d04363ee1e 100644
--- a/src/mesa/drivers/dri/i965/brw_nir.c
+++ b/src/mesa/drivers/dri/i965/brw_nir.c
@@ -22,6 +22,7 @@
  */
 
 #include "brw_nir.h"
+#include "brw_shader.h"
 #include "glsl/glsl_parser_extras.h"
 #include "glsl/nir/glsl_to_nir.h"
 #include "program/prog_to_nir.h"
@@ -113,19 +114,22 @@ brw_create_nir(struct brw_context *brw,
       nir_assign_var_locations_direct_first(nir, &nir->uniforms,
                                             &nir->num_direct_uniforms,
                                             &nir->num_uniforms,
-                                            is_scalar);
-      nir_assign_var_locations(&nir->outputs, &nir->num_outputs, is_scalar);
+                                            type_size_scalar);
+      nir_assign_var_locations(&nir->inputs, &nir->num_inputs, type_size_scalar);
+      nir_assign_var_locations(&nir->outputs, &nir->num_outputs, type_size_scalar);
+      nir_lower_io(nir, type_size_scalar);
    } else {
       nir_assign_var_locations(&nir->uniforms,
                                &nir->num_uniforms,
-                               is_scalar);
+                               type_size_vec4);
+
+      nir_assign_var_locations(&nir->inputs, &nir->num_inputs, type_size_vec4);
 
       foreach_list_typed(nir_variable, var, node, &nir->outputs)
          var->data.driver_location = var->data.location;
-   }
-   nir_assign_var_locations(&nir->inputs, &nir->num_inputs, is_scalar);
 
-   nir_lower_io(nir, is_scalar);
+      nir_lower_io(nir, type_size_vec4);
+   }
 
    nir_validate_shader(nir);