Mesa (master): mesa: port the LastLookedUpVAO optimisation to _mesa_lookup_vao()

[Samuel Pitoiset]

Module: Mesa
Branch: master
Commit: 5946806064db29f6bf13a44307326be4d1a0f3f4
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=5946806064db29f6bf13a44307326be4d1a0f3f4

Author: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Date:   Thu Aug 24 15:53:34 2017 +0200

mesa: port the LastLookedUpVAO optimisation to _mesa_lookup_vao()

It was only used in the errors path.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Reviewed-by: Timothy Arceri <tarceri at itsqueeze.com>

---

 src/mesa/main/arrayobj.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/mesa/main/arrayobj.c b/src/mesa/main/arrayobj.c
index 600177cc5c..88a5702f41 100644
--- a/src/mesa/main/arrayobj.c
+++ b/src/mesa/main/arrayobj.c
@@ -66,11 +66,23 @@
 struct gl_vertex_array_object *
 _mesa_lookup_vao(struct gl_context *ctx, GLuint id)
 {
-   if (id == 0)
+   if (id == 0) {
       return NULL;
-   else
-      return (struct gl_vertex_array_object *)
-         _mesa_HashLookupLocked(ctx->Array.Objects, id);
+   } else {
+      struct gl_vertex_array_object *vao;
+
+      if (ctx->Array.LastLookedUpVAO &&
+          ctx->Array.LastLookedUpVAO->Name == id) {
+         vao = ctx->Array.LastLookedUpVAO;
+      } else {
+         vao = (struct gl_vertex_array_object *)
+            _mesa_HashLookupLocked(ctx->Array.Objects, id);
+
+         _mesa_reference_vao(ctx, &ctx->Array.LastLookedUpVAO, vao);
+      }
+
+      return vao;
+   }
 }