r300/compiler: Fix bug in rc_get_variables()

Variables that write to the same source select need to pe paired
together otherwise the register allocator might fail.

https://bugs.freedesktop.org/show_bug.cgi?id=36753

diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_variable.c b/src/mesa/drivers/dri/r300/compiler/radeon_variable.c
index 33181bdcc888c96551312e1f5aad029bece47fe2..938fb8421f295a348737fa30e609a8a3c36797a3 100644 (file)
--- a/src/mesa/drivers/dri/r300/compiler/radeon_variable.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_variable.c
@@ -292,20 +292,20 @@ struct rc_variable * rc_variable(
 }
 
 static void get_variable_helper(
-       struct rc_list ** aborted_list,
        struct rc_list ** variable_list,
-       unsigned int aborted,
        struct rc_variable * variable)
 {
-       if (aborted) {
-               rc_list_add(aborted_list, rc_list(&variable->C->Pool, variable));
-       } else {
-               rc_list_add(variable_list, rc_list(&variable->C->Pool, variable));
+       struct rc_list * list_ptr;
+       for (list_ptr = *variable_list; list_ptr; list_ptr = list_ptr->Next) {
+               if (readers_intersect(variable, list_ptr->Item)) {
+                       rc_variable_add_friend(list_ptr->Item, variable);
+                       return;
+               }
        }
+       rc_list_add(variable_list, rc_list(&variable->C->Pool, variable));
 }
 
 static void get_variable_pair_helper(
-       struct rc_list ** aborted_list,
        struct rc_list ** variable_list,
        struct radeon_compiler * c,
        struct rc_instruction * inst,
@@ -338,8 +338,7 @@ static void get_variable_pair_helper(
        }
        new_var = rc_variable(c, file, sub_inst->DestIndex, writemask,
                                                                &reader_data);
-       get_variable_helper(aborted_list, variable_list, reader_data.Abort,
-                                                               new_var);
+       get_variable_helper(variable_list, new_var);
 }
 
 /**
@@ -352,10 +351,7 @@ static void get_variable_pair_helper(
 struct rc_list * rc_get_variables(struct radeon_compiler * c)
 {
        struct rc_instruction * inst;
-       struct rc_list * aborted_list = NULL;
        struct rc_list * variable_list = NULL;
-       struct rc_list * var_ptr;
-       struct rc_list * search_ptr;
 
        for (inst = c->Program.Instructions.Next;
                                        inst != &c->Program.Instructions;
@@ -372,43 +368,15 @@ struct rc_list * rc_get_variables(struct radeon_compiler * c)
                        new_var = rc_variable(c, inst->U.I.DstReg.File,
                                inst->U.I.DstReg.Index,
                                inst->U.I.DstReg.WriteMask, &reader_data);
-                       get_variable_helper(&aborted_list, &variable_list,
-                                               reader_data.Abort, new_var);
+                       get_variable_helper(&variable_list, new_var);
                } else {
-                       get_variable_pair_helper(&aborted_list, &variable_list,
-                                       c, inst, &inst->U.P.RGB);
-                       get_variable_pair_helper(&aborted_list, &variable_list,
-                                       c, inst, &inst->U.P.Alpha);
+                       get_variable_pair_helper(&variable_list, c, inst,
+                                                       &inst->U.P.RGB);
+                       get_variable_pair_helper(&variable_list, c, inst,
+                                                       &inst->U.P.Alpha);
                }
        }
 
-       /* The aborted_list contains a list of variables that might share a
-        * reader with another variable.  We need to search through this list
-        * and pair together variables that do share the same reader.
-        */
-       while (aborted_list) {
-               struct rc_list * search_ptr_next;
-               struct rc_variable * var;
-               var_ptr = aborted_list;
-               for (var = var_ptr->Item; var; var = var->Friend) {
-
-                       search_ptr = var_ptr->Next;
-                       while(search_ptr) {
-                               search_ptr_next = search_ptr->Next;
-                               if (readers_intersect(var, search_ptr->Item)){
-                                       rc_list_remove(&aborted_list,
-                                                       search_ptr);
-                                       rc_variable_add_friend(var,
-                                                       search_ptr->Item);
-                               }
-                               search_ptr = search_ptr_next;
-                       }
-               }
-               rc_list_remove(&aborted_list, var_ptr);
-               rc_list_add(&variable_list, rc_list(
-                       &((struct rc_variable*)(var_ptr->Item))->C->Pool,
-                       var_ptr->Item));
-       }
        return variable_list;
 }