i965: Prefer Y-tiling on Gen6+.

In the past, we preferred X-tiling for color buffers because our BLT
code couldn't handle Y-tiling.  However, the BLT paths have been largely
replaced by BLORP on Gen6+, which can handle any kind of tiling.

We hadn't measured any performance improvement in the past, but that's
probably because compressed textures were all untiled anyway.

Improves performance in GLB27_TRex_C24Z16_FixedTime by 7.69231%.

v2: Rebase on top of Eric's untiled-for-larger-than-aperture changes.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

diff --git a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
index 859bcd6..38c0149 100644 (file)
--- a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
+++ b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
@@ -346,7 +346,7 @@ intel_miptree_choose_tiling(struct intel_context *intel,
 
    if (width0 >= 64) {
       if (ALIGN(mt->total_width * mt->cpp, 512) < 32768)
-         return I915_TILING_X;
+         return intel->gen >= 6 ? I915_TILING_Y : I915_TILING_X;
 
       perf_debug("%dx%d miptree too large to blit, falling back to untiled",
                  mt->total_width, mt->total_height);