Mesa (7.9): glsl: Add a virtual as_discard() method.

[Ian Romanick]

Module: Mesa
Branch: 7.9
Commit: 1e2e387a157e4eb5d0816ae958bdb0637a2cfc9b
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=1e2e387a157e4eb5d0816ae958bdb0637a2cfc9b

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Wed Nov 24 21:33:07 2010 -0800

glsl: Add a virtual as_discard() method.

NOTE: This is candidate for the 7.9 branch.
(cherry picked from commit 1eb7a81f2e43842acd59929ce65db2142b69134d)

---

 src/glsl/ir.h |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index fa246b5..e0347fb 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -125,6 +125,7 @@ public:
    virtual class ir_if *                as_if()               { return NULL; }
    virtual class ir_swizzle *           as_swizzle()          { return NULL; }
    virtual class ir_constant *          as_constant()         { return NULL; }
+   virtual class ir_discard *           as_discard()          { return NULL; }
    /*@}*/
 
 protected:
@@ -1044,6 +1045,11 @@ public:
 
    virtual ir_visitor_status accept(ir_hierarchical_visitor *);
 
+   virtual ir_discard *as_discard()
+   {
+      return this;
+   }
+
    ir_rvalue *condition;
 };
 /*@}*/