mesa: Fix and speedup gl_array_object::_MaxElement computation.

Use a bitmask approach to compute gl_array_object::_MaxElement.
To make this work correctly depending on the shader type actually used,
make use of the newly introduced typed bitmask getters.
With this change I gain about 5% draw time on some osgviewer examples.

Signed-off-by: Mathias Fröhlich <[email protected]>
Reviewed-by: Brian Paul <[email protected]>

1 files changed, 27 insertions, 14 deletions

diff --git a/src/mesa/main/arrayobj.c b/src/mesa/main/arrayobj.c
index 29bfed8f51e..3287745432f 100644
--- a/src/mesa/main/arrayobj.c
+++ b/src/mesa/main/arrayobj.c
@@ -280,15 +280,26 @@ remove_array_object( struct gl_context *ctx, struct gl_array_object *obj )
 
 
 /**
- * Helper for update_arrays().
- * \return  min(current min, array->_MaxElement).
+ * Helper for _mesa_update_array_object_max_element().
+ * \return  min(arrayObj->VertexAttrib[*]._MaxElement).
  */
 static GLuint
-update_min(GLuint min, struct gl_client_array *array)
+compute_max_element(struct gl_array_object *arrayObj, GLbitfield64 enabled)
 {
-   assert(array->Enabled);
-   _mesa_update_array_max_element(array);
-   return MIN2(min, array->_MaxElement);
+   GLuint min = ~((GLuint)0);
+   
+   while (enabled) {
+      struct gl_client_array *client_array;
+      GLint attrib = ffsll(enabled) - 1;
+      enabled ^= BITFIELD64_BIT(attrib);
+      
+      client_array = &arrayObj->VertexAttrib[attrib];
+      assert(client_array->Enabled);
+      _mesa_update_array_max_element(client_array);
+      min = MIN2(min, client_array->_MaxElement);
+   }
+   
+   return min;
 }
 
 
@@ -299,17 +310,19 @@ void
 _mesa_update_array_object_max_element(struct gl_context *ctx,
                                       struct gl_array_object *arrayObj)
 {
-   GLbitfield64 enabled = arrayObj->_Enabled;
-   GLuint min = ~0u;
-
-   while (enabled) {
-      GLint attrib = ffsll(enabled) - 1;
-      enabled &= ~BITFIELD64_BIT(attrib);
-      min = update_min(min, &arrayObj->VertexAttrib[attrib]);
+   GLbitfield64 enabled;
+
+   if (!ctx->VertexProgram._Current ||
+       ctx->VertexProgram._Current == ctx->VertexProgram._TnlProgram) {
+      enabled = _mesa_array_object_get_enabled_ff(arrayObj);
+   } else if (ctx->VertexProgram._Current->IsNVProgram) {
+      enabled = _mesa_array_object_get_enabled_nv(arrayObj);
+   } else {
+      enabled = _mesa_array_object_get_enabled_arb(arrayObj);
    }
 
    /* _MaxElement is one past the last legal array element */
-   arrayObj->_MaxElement = min;
+   arrayObj->_MaxElement = compute_max_element(arrayObj, enabled);
 }