glsl2: Don't tree-grafting out assignment to an out variable.

Fixes:
glsl-deadcode-varying.

diff --git a/src/glsl/ir_tree_grafting.cpp b/src/glsl/ir_tree_grafting.cpp
index 38034a6197797f208aca36a5d9532ad2c6302f03..1a742f412cb8f7f84ecf23044adfc48a00172ffd 100644 (file)
--- a/src/glsl/ir_tree_grafting.cpp
+++ b/src/glsl/ir_tree_grafting.cpp
@@ -319,6 +319,10 @@ tree_grafting_basic_block(ir_instruction *bb_first,
       if (!lhs_var)
         continue;
 
+      if (lhs_var->mode == ir_var_out ||
+         lhs_var->mode == ir_var_inout)
+        continue;
+
       struct variable_entry *entry = info->refs->get_variable_entry(lhs_var);
 
       if (!entry->declaration ||