From: Eric Anholt <eric@anholt.net>
Date: Thu, 31 Oct 2013 07:10:32 +0000 (-0700)
Subject: glsl: Apply the transformation "(a || a) -> a" in opt_algebraic.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ee2704826264eba22d095c3e1e03a8532b7bd1e6;p=mesa.git

glsl: Apply the transformation "(a || a) -> a" in opt_algebraic.

total instructions in shared programs: 1732385 -> 1732373 (-0.00%)
instructions in affected programs:     416 -> 404 (-2.88%)
GAINED:                                0
LOST:                                  0

(That's 4 already-short fragment shaders in dota2)

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
---

diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp
index a07e153ae92..3da27e5d61c 100644
--- a/src/glsl/opt_algebraic.cpp
+++ b/src/glsl/opt_algebraic.cpp
@@ -388,7 +388,6 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
       break;
 
    case ir_binop_logic_or:
-      /* FINISHME: Also simplify (a || a) to (a). */
       if (is_vec_zero(op_const[0])) {
 	 return ir->operands[1];
       } else if (is_vec_zero(op_const[1])) {
@@ -407,6 +406,9 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
           */
          return logic_not(logic_and(op_expr[0]->operands[0],
                                     op_expr[1]->operands[0]));
+      } else if (ir->operands[0]->equals(ir->operands[1])) {
+         /* (a || a) == a */
+         return ir->operands[0];
       }
       break;