sna/traps: Unroll insertion sort

As the compiler cannot know the loop is bounded by a sentinel, manually
unroll it.

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

1 files changed, 8 insertions, 0 deletions

diff --git a/src/sna/sna_trapezoids.c b/src/sna/sna_trapezoids.c
index 33ea3bbb..8e735efe 100644
--- a/src/sna/sna_trapezoids.c
+++ b/src/sna/sna_trapezoids.c
@@ -556,6 +556,14 @@ cell_list_find(struct cell_list *cells, int x)
 			break;
 
 		tail = tail->next;
+		if (tail->next->x > x)
+			break;
+
+		tail = tail->next;
+		if (tail->next->x > x)
+			break;
+
+		tail = tail->next;
 	} while (1);
 
 	if (tail->x != x)