[gtk+/wip/otte/shader: 51/98] gskslexpression: Add spv writing optimization

[Benjamin Otte <otte src gnome org>]

commit 4a40d24be70630e67aed7eead435ce7b17791041
Author: Benjamin Otte <otte redhat com>
Date:   Tue Oct 10 04:02:08 2017 +0200

    gskslexpression: Add spv writing optimization
    
    For assignable expressions, we can always use an access chain to query
    the value. Access chains are not just faster, they also contain lots of
    optimizations for merging swizzles and whatnot.

 gsk/gskslexpression.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)
---
diff --git a/gsk/gskslexpression.c b/gsk/gskslexpression.c
index e8abf0a..f40b27d 100644
--- a/gsk/gskslexpression.c
+++ b/gsk/gskslexpression.c
@@ -2655,5 +2655,16 @@ guint32
 gsk_sl_expression_write_spv (const GskSlExpression *expression,
                              GskSpvWriter          *writer)
 {
+  GskSpvAccessChain *chain;
+  guint32 result_id;
+
+  chain = gsk_sl_expression_get_spv_access_chain (expression, writer);
+  if (chain)
+    {
+      result_id = gsk_spv_access_chain_load (chain);
+      gsk_spv_access_chain_free (chain);
+      return result_id;
+    }
+
   return expression->class->write_spv (expression, writer);
 }