Mesa (master): mesa: Avoid flagging _NEW_VIEWPORT on redundant viewport updates.

[Kenneth Graunke]

Module: Mesa
Branch: master
Commit: 95073a2dca03a48f4c77bc846a4a6d1f0eb81ae6
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=95073a2dca03a48f4c77bc846a4a6d1f0eb81ae6

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Fri Sep 26 15:13:30 2014 -0700

mesa: Avoid flagging _NEW_VIEWPORT on redundant viewport updates.

Cuts the number of i965 color calculator viewport uploads by 100x
(11017983 -> 113385) in 'x11perf -gc' with Glamor in Xephyr.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Brian Paul <brianp at vmware.com>
Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

---

 src/mesa/main/viewport.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/mesa/main/viewport.c b/src/mesa/main/viewport.c
index 6545bf6..222ae30 100644
--- a/src/mesa/main/viewport.c
+++ b/src/mesa/main/viewport.c
@@ -58,6 +58,12 @@ set_viewport_no_notify(struct gl_context *ctx, unsigned idx,
                 ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
    }
 
+   if (ctx->ViewportArray[idx].X == x &&
+       ctx->ViewportArray[idx].Width == width &&
+       ctx->ViewportArray[idx].Y == y &&
+       ctx->ViewportArray[idx].Height == height)
+      return;
+
    ctx->ViewportArray[idx].X = x;
    ctx->ViewportArray[idx].Width = width;
    ctx->ViewportArray[idx].Y = y;