From: Matt Turner <mattst88@gmail.com>
Date: Mon, 24 Feb 2014 23:00:44 +0000 (-0800)
Subject: glsl: Optimize lrp(0, y, a) into y * a.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ecc6c3d4ab31c6cd848bce02790000c165a02229;p=mesa.git

glsl: Optimize lrp(0, y, a) into y * a.

Helps two programs in shader-db:

instructions in affected programs:     254 -> 234 (-7.87%)

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
---

diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp
index 1b4d319366c..28f95a44c7f 100644
--- a/src/glsl/opt_algebraic.cpp
+++ b/src/glsl/opt_algebraic.cpp
@@ -568,6 +568,8 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
          return ir->operands[1];
       } else if (ir->operands[0]->equals(ir->operands[1])) {
          return ir->operands[0];
+      } else if (is_vec_zero(op_const[0])) {
+         return mul(ir->operands[1], ir->operands[2]);
       }
       break;