[Mesa-dev] [PATCH 3/3] glsl: Optimize division by two with a right shift.

[Matt Turner]

---
 src/glsl/opt_algebraic.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp
index 778638c..50342ac 100644
--- a/src/glsl/opt_algebraic.cpp
+++ b/src/glsl/opt_algebraic.cpp
@@ -421,6 +421,9 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
       }
       if (is_vec_one(op_const[1]))
         return ir->operands[0];
+      if (is_vec_two(op_const[1]) && ir->type->is_integer()) {
+         return rshift(ir->operands[0], new(mem_ctx) ir_constant(1));
+      }
       break;
 
    case ir_binop_dot:
-- 
1.8.3.2

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