glsl: Optimize triop_csel with all-true or all-false.

Reviewed-by: Matt Turner <mattst88@gmail.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp
index 7863fe8f9c..1b4d319366 100644
--- a/src/glsl/opt_algebraic.cpp
+++ b/src/glsl/opt_algebraic.cpp
@@ -571,6 +571,13 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
       }
       break;
 
+   case ir_triop_csel:
+      if (is_vec_one(op_const[0]))
+	 return ir->operands[1];
+      if (is_vec_zero(op_const[0]))
+	 return ir->operands[2];
+      break;
+
    default:
       break;
    }