From: Matt Turner <mattst88@gmail.com>
Date: Mon, 4 Jun 2012 20:17:12 +0000 (-0400)
Subject: glsl: Check for zero vectors in ir_binop_dot
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d7bef19c7ff40f0b83a42fdb8509eed3ad1e40a3;p=mesa.git

glsl: Check for zero vectors in ir_binop_dot

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
---

diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp
index d3976126050..5a9881dbebe 100644
--- a/src/glsl/opt_algebraic.cpp
+++ b/src/glsl/opt_algebraic.cpp
@@ -309,6 +309,13 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
       }
       break;
 
+   case ir_binop_dot:
+      if (is_vec_zero(op_const[0]) || is_vec_zero(op_const[1])) {
+	 this->progress = true;
+	 return ir_constant::zero(mem_ctx, ir->type);
+      }
+      break;
+
    case ir_binop_logic_and:
       /* FINISHME: Also simplify (a && a) to (a). */
       if (is_vec_one(op_const[0])) {