[Mesa-dev] [PATCH 2.5/4] glsl: Reduce overhead in conditional discard optimization

[Thomas Helland]

Don't descend into assignments. This is the same optimization
that is already done in opt_if_simplification.
---
 src/compiler/glsl/opt_conditional_discard.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/compiler/glsl/opt_conditional_discard.cpp b/src/compiler/glsl/opt_conditional_discard.cpp
index 6d8a23460d..d7cb2069ed 100644
--- a/src/compiler/glsl/opt_conditional_discard.cpp
+++ b/src/compiler/glsl/opt_conditional_discard.cpp
@@ -46,12 +46,23 @@ public:
    }
 
    ir_visitor_status visit_leave(ir_if *);
+   ir_visitor_status visit_enter(ir_assignment *);
 
    bool progress;
 };
 
 } /* anonymous namespace */
 
+/* We only care about the top level "if" instructions, so don't
+ * descend into expressions.
+ */
+ir_visitor_status
+opt_conditional_discard_visitor::visit_enter(ir_assignment *ir)
+{
+   (void) ir;
+   return visit_continue_with_parent;
+}
+
 bool
 opt_conditional_discard(exec_list *instructions)
 {
-- 
2.12.2