i965: take care of doubles when lowering VS inputs

Input attributes can require 2 vec4 or 1 vec4 depending on whether they
are double-precision or not.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/mesa/drivers/dri/i965/brw_fs.cpp

@@ -545,6 +545,19 @@ type_size_vec4_times_4(const struct glsl_type *type)
    return 4 * type_size_vec4(type);
 }
 
+/* Attribute arrays are loaded as one vec4 per element (or matrix column),
+ * except for double-precision types, which are loaded as one dvec4.
+ */
+extern "C" int
+type_size_vs_input(const struct glsl_type *type)
+{
+   if (type->is_double()) {
+      return type_size_vec4(type) / 2;
+   } else {
+      return type_size_vec4(type);
+   }
+}
+
 /**
  * Create a MOV to read the timestamp register.
  *

src/mesa/drivers/dri/i965/brw_nir.c

@@ -23,6 +23,7 @@
 
 #include "brw_nir.h"
 #include "brw_shader.h"
+#include "compiler/glsl_types.h"
 #include "compiler/nir/glsl_to_nir.h"
 #include "compiler/nir/nir_builder.h"
 #include "program/prog_to_nir.h"
@@ -205,7 +206,7 @@ brw_nir_lower_vs_inputs(nir_shader *nir,
     * loaded as one vec4 or dvec4 per element (or matrix column), depending on
     * whether it is a double-precision type or not.
     */
-   nir_lower_io(nir, nir_var_shader_in, type_size_vec4);
+   nir_lower_io(nir, nir_var_shader_in, type_size_vs_input);
 
    /* This pass needs actual constants */
    nir_opt_constant_folding(nir);

src/mesa/drivers/dri/i965/brw_shader.h

@@ -294,6 +294,7 @@ struct gl_shader *brw_new_shader(struct gl_context *ctx, GLuint name, GLuint typ
 int type_size_scalar(const struct glsl_type *type);
 int type_size_vec4(const struct glsl_type *type);
 int type_size_vec4_times_4(const struct glsl_type *type);
+int type_size_vs_input(const struct glsl_type *type);
 
 unsigned tesslevel_outer_components(GLenum tes_primitive_mode);
 unsigned tesslevel_inner_components(GLenum tes_primitive_mode);