[Mesa-dev] [PATCH 2/3] glsl: Optimize clamp(x, 0.0, b), where b < 1.0 as saturate(min(x, b))

[Abdiel Janulgue]

Signed-off-by: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
---
 src/glsl/opt_algebraic.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp
index 8d7609d..0d694b6 100644
--- a/src/glsl/opt_algebraic.cpp
+++ b/src/glsl/opt_algebraic.cpp
@@ -589,6 +589,10 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
             /* Found a min (max(x, 0), 1.0) */
             if (outer_const->is_one() && inner_val_a->is_zero())
                return saturate(inner_val_b);
+
+            /* Found a min (max(x, 0.0) b), where b < 1.0 */
+            if ((outer_const->get_float_component(0) < 1.0f) && inner_val_b->is_zero())
+               return saturate(expr(ir_binop_min, inner_val_a, outer_const));
          }
       }
 
-- 
1.9.1