Mesa (10.1): glsl: Don't vectorize horizontal expressions.

[Ian Romanick]

Module: Mesa
Branch: 10.1
Commit: 3305b9c96b8c1f00e66bda59aa69b44a5ff861db
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=3305b9c96b8c1f00e66bda59aa69b44a5ff861db

Author: Matt Turner <mattst88 at gmail.com>
Date:   Sat Feb 22 16:35:15 2014 -0800

glsl: Don't vectorize horizontal expressions.

Cc: "10.1" <mesa-stable at lists.freedesktop.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75224
(cherry picked from commit 4bd7f1d044eee17587d6523322303a61aeb8d660)

---

 src/glsl/opt_vectorize.cpp |   15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/glsl/opt_vectorize.cpp b/src/glsl/opt_vectorize.cpp
index dba303d..13faac0 100644
--- a/src/glsl/opt_vectorize.cpp
+++ b/src/glsl/opt_vectorize.cpp
@@ -83,6 +83,7 @@ public:
    virtual ir_visitor_status visit_enter(ir_assignment *);
    virtual ir_visitor_status visit_enter(ir_swizzle *);
    virtual ir_visitor_status visit_enter(ir_dereference_array *);
+   virtual ir_visitor_status visit_enter(ir_expression *);
    virtual ir_visitor_status visit_enter(ir_if *);
    virtual ir_visitor_status visit_enter(ir_loop *);
 
@@ -303,6 +304,20 @@ ir_vectorize_visitor::visit_enter(ir_dereference_array *ir)
    return visit_continue_with_parent;
 }
 
+/**
+ * Upon entering an ir_expression, remove the current assignment from further
+ * consideration if the expression operates horizontally on vectors.
+ */
+ir_visitor_status
+ir_vectorize_visitor::visit_enter(ir_expression *ir)
+{
+   if (ir->is_horizontal()) {
+      this->current_assignment = NULL;
+      return visit_continue_with_parent;
+   }
+   return visit_continue;
+}
+
 /* Since there is no statement to visit between the "then" and "else"
  * instructions try to vectorize before, in between, and after them to avoid
  * combining statements from different basic blocks.