[Mesa-dev] [PATCH 3/6] glsl: Optimize pow(x, 1) -> x.

[Eric Anholt]

total instructions in shared programs: 1627826 -> 1627754 (-0.00%)
instructions in affected programs:     6640 -> 6568 (-1.08%)
GAINED:                                0
LOST:                                  0

(HoN and savage2)
---
 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 4aa49e5..918982a 100644
--- a/src/glsl/opt_algebraic.cpp
+++ b/src/glsl/opt_algebraic.cpp
@@ -475,6 +475,10 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
       if (is_vec_one(op_const[0]))
          return op_const[0];
 
+      /* x^1 == x */
+      if (is_vec_one(op_const[1]))
+         return ir->operands[0];
+
       /* pow(2,x) == exp2(x) */
       if (is_vec_two(op_const[0]))
          return expr(ir_unop_exp2, ir->operands[1]);
-- 
1.8.5.2