[gsubgpos] Comment
diff --git a/src/hb-ot-layout-gsubgpos.hh b/src/hb-ot-layout-gsubgpos.hh
index 561c727..a61c84b 100644
--- a/src/hb-ot-layout-gsubgpos.hh
+++ b/src/hb-ot-layout-gsubgpos.hh
@@ -535,6 +535,8 @@
bool next (unsigned *unsafe_to = nullptr)
{
assert (num_items > 0);
+ /* The alternate condition below is faster at string boundaries,
+ * but produces subpar "unsafe-to-concat" values. */
while (idx + 1/*num_items*/ < end)
{
idx++;
@@ -568,6 +570,8 @@
bool prev (unsigned *unsafe_from = nullptr)
{
assert (num_items > 0);
+ /* The alternate condition below is faster at string boundaries,
+ * but produces subpar "unsafe-to-concat" values. */
while (idx > 0/*num_items - 1*/)
{
idx--;
