sna: Store damage-all in the low bit of the damage pointer

Avoid the function call overhead by inspecting the low bit to see if it
is all-damaged already.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 11 insertions, 9 deletions

diff --git a/src/sna/sna_composite.c b/src/sna/sna_composite.c
index b1bee98b..f8f61f5a 100644
--- a/src/sna/sna_composite.c
+++ b/src/sna/sna_composite.c
@@ -763,18 +763,20 @@ sna_composite_rectangles(CARD8		 op,
 		goto fallback;
 	}
 
-	assert_pixmap_contains_box(pixmap, RegionExtents(&region));
-
 	/* Clearing a pixmap after creation is a common operation, so take
 	 * advantage and reduce further damage operations.
 	 */
-	if (region.data == NULL &&
-	    region.extents.x2 - region.extents.x1 == pixmap->drawable.width &&
-	    region.extents.y2 - region.extents.y1 == pixmap->drawable.height)
-		sna_damage_all(&priv->gpu_damage,
-			       pixmap->drawable.width, pixmap->drawable.height);
-	else
-		sna_damage_add(&priv->gpu_damage, &region);
+	if (!DAMAGE_IS_ALL(priv->gpu_damage)) {
+		assert_pixmap_contains_box(pixmap, RegionExtents(&region));
+
+		if (region.data == NULL &&
+		    region.extents.x2 - region.extents.x1 == pixmap->drawable.width &&
+		    region.extents.y2 - region.extents.y1 == pixmap->drawable.height)
+			sna_damage_all(&priv->gpu_damage,
+				       pixmap->drawable.width, pixmap->drawable.height);
+		else
+			sna_damage_add(&priv->gpu_damage, &region);
+	}
 
 	goto done;