[Mesa-dev] [PATCH 5/5] glsl: Update array access tracker of function parameters.

[Fabian Bieler]

Uniform arrays are subject to beeing shrunk if higher members were not accessed.
Update the max_array_access flag so array members that were only accessed in
the function are not optimized away.

This fixes Piglit test
spec/glsl-1.10/execution/samplers/in-parameter-array.shader_test.

Signed-off-by: Fabian Bieler <fabianbieler at fastmail.fm>
---
 src/glsl/ast_function.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/glsl/ast_function.cpp b/src/glsl/ast_function.cpp
index 00e0c05..9378894 100644
--- a/src/glsl/ast_function.cpp
+++ b/src/glsl/ast_function.cpp
@@ -322,6 +322,18 @@ generate_call(exec_list *instructions, ir_function_signature *sig,
 	    assert (!"Illegal formal parameter mode");
 	    break;
 	 }
+      } else if (formal->type->is_array()) {
+	 /* Update the max_array_access field for array parameters.
+	  * If the max_array_access of the formal parameter is zero, chances
+	  * are we haven't parsed the function yet. Just set the array access
+	  * to the whole array in that case.
+	  */
+	 const unsigned max_array_access = (formal->max_array_access != 0)
+	    ? formal->max_array_access : (formal->type->array_size() - 1);
+	 ir_variable *var = actual->whole_variable_referenced();
+	 if (var)
+	    var->max_array_access =
+	       MAX2(var->max_array_access, max_array_access);
       }
 
       actual_iter.next();
-- 
1.8.1.2