[Mesa-dev] [PATCH 1/6] glsl: Optimize ~~x into x.

[Eric Anholt]

---
 src/glsl/opt_algebraic.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp
index 332f0b7..6b0d992 100644
--- a/src/glsl/opt_algebraic.cpp
+++ b/src/glsl/opt_algebraic.cpp
@@ -218,6 +218,18 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
       this->mem_ctx = ralloc_parent(ir);
 
    switch (ir->operation) {
+   case ir_unop_bit_not:
+      if (op_expr[0] == NULL)
+	 break;
+
+      switch (op_expr[0]->operation) {
+      case ir_unop_bit_not:
+         return abs(op_expr[0]->operands[0]);
+      default:
+         break;
+      }
+      break;
+
    case ir_unop_abs:
       if (op_expr[0] == NULL)
 	 break;
-- 
1.8.5.2