[PATCH] wined3d/resource: Performance improvement

[Patrick Rudolph]

Tests on Windows showed that mapping a buffer with flags WINED3D_MAP_DISCARD
and WINED3D_MAP_NOOVERWRITE is valid combination. Writing reliable tests
is difficult as the driver is free to choose when using discard.

Unigine Heavon maps a lot of buffers with both flags, but run on about
85% GPU-load, as WINE removes both hints and the game has to wait for
the buffer to be mapped.

Pass both flags to the driver.

Unigine Heavon's score increased from 580 to 700, which is an increase of 20%.

Tested on:
OpenGL renderer string: Gallium 0.4 on AMD BARTS (DRM 2.43.0 / 4.5.7-300.fc24.x86_64, LLVM 3.8.0)
OpenGL core profile version string: 3.3 (Core Profile) Mesa 12.1.0-devel (git-60c68c5)

This patch hasn't been tested on other GPUs and drivers.

Signed-off-by: Patrick Rudolph <siro at das-labor.org>
---
 dlls/wined3d/resource.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/dlls/wined3d/resource.c b/dlls/wined3d/resource.c
index be7dfb4..ea26a9f 100644
--- a/dlls/wined3d/resource.c
+++ b/dlls/wined3d/resource.c
@@ -363,12 +363,8 @@ DWORD wined3d_resource_sanitize_map_flags(const struct wined3d_resource *resourc
             return 0;
         }
     }
-    else if ((flags & (WINED3D_MAP_DISCARD | WINED3D_MAP_NOOVERWRITE))
-            == (WINED3D_MAP_DISCARD | WINED3D_MAP_NOOVERWRITE))
-    {
-        WARN("WINED3D_MAP_DISCARD and WINED3D_MAP_NOOVERWRITE used together, ignoring.\n");
-        return 0;
-    }
+    /* Unigine Heavon uses DISCARD and NOOVERWRITE at the same time.
+     * Tests showed that it's a valid combination. */
     else if (flags & (WINED3D_MAP_DISCARD | WINED3D_MAP_NOOVERWRITE)
             && !(resource->usage & WINED3DUSAGE_DYNAMIC))
     {
-- 
2.7.4