[PATCH 2/2] glamor: use write only for putimage in some cases

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

Ilia pointed out that xlock -mode wator is slow, this speeds it
up by avoiding the ReadPixels on every frame.

The current criteria for putimage is

a) ALU copy operation
b) planemask all set
c) region is contained inside pCompositeClip

Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 glamor/glamor_image.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/glamor/glamor_image.c b/glamor/glamor_image.c
index 3158749..a190d3e 100644
--- a/glamor/glamor_image.c
+++ b/glamor/glamor_image.c
@@ -88,7 +88,19 @@ static void
 glamor_put_image_bail(DrawablePtr drawable, GCPtr gc, int depth, int x, int y,
                       int w, int h, int leftPad, int format, char *bits)
 {
-    if (glamor_prepare_access_box(drawable, GLAMOR_ACCESS_RW, x, y, w, h))
+    int access = GLAMOR_ACCESS_RW;
+
+    if (gc->alu == GXcopy && glamor_pm_is_solid(gc->depth, gc->planemask)) {
+	BoxRec box;
+	box.x1 = x;
+	box.y1 = y;
+	box.x2 = x + w;
+	box.y2 = y + h;
+
+	if (RegionContainsRect(gc->pCompositeClip, &box))
+            access = GLAMOR_ACCESS_WO;
+    }
+    if (glamor_prepare_access_box(drawable, access, x, y, w, h))
         fbPutImage(drawable, gc, depth, x, y, w, h, leftPad, format, bits);
     glamor_finish_access(drawable);
 }
-- 
2.5.0