sna: Rework the num_threads refinement to avoid the division

We can replace the division by a multiplication.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/src/sna/sna_trapezoids_mono.c b/src/sna/sna_trapezoids_mono.c
index 790863e8..2f7a2bb8 100644
--- a/src/sna/sna_trapezoids_mono.c
+++ b/src/sna/sna_trapezoids_mono.c
@@ -843,7 +843,7 @@ mono_trapezoids_span_converter(struct sna *sna,
 		y = extents.y1;
 		h = extents.y2 - extents.y1;
 		h = (h + num_threads - 1) / num_threads;
-		num_threads = (extents.y2 - extents.y1 + h - 1) / h;
+		num_threads -= (num_threads-1) * h >= extents.y2 - extents.y1;
 
 		for (n = 1; n < num_threads; n++) {
 			threads[n] = threads[0];