[Mesa-dev] [PATCH 2/6] glsl: Optimize log(exp(x)) and exp(log(x)) into x.

[Eric Anholt]

---
 src/glsl/opt_algebraic.cpp | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp
index 6b0d992..4aa49e5 100644
--- a/src/glsl/opt_algebraic.cpp
+++ b/src/glsl/opt_algebraic.cpp
@@ -252,6 +252,42 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
       }
       break;
 
+   case ir_unop_exp:
+      if (op_expr[0] == NULL)
+	 break;
+
+      if (op_expr[0]->operation == ir_unop_log) {
+         return op_expr[0]->operands[0];
+      }
+      break;
+
+   case ir_unop_log:
+      if (op_expr[0] == NULL)
+	 break;
+
+      if (op_expr[0]->operation == ir_unop_exp) {
+         return op_expr[0]->operands[0];
+      }
+      break;
+
+   case ir_unop_exp2:
+      if (op_expr[0] == NULL)
+	 break;
+
+      if (op_expr[0]->operation == ir_unop_log2) {
+         return op_expr[0]->operands[0];
+      }
+      break;
+
+   case ir_unop_log2:
+      if (op_expr[0] == NULL)
+	 break;
+
+      if (op_expr[0]->operation == ir_unop_exp2) {
+         return op_expr[0]->operands[0];
+      }
+      break;
+
    case ir_unop_logic_not: {
       enum ir_expression_operation new_op = ir_unop_logic_not;
 
-- 
1.8.5.2