Improved comments.

1 files changed, 2 insertions, 1 deletions

diff --git a/readme.md b/readme.md
index 5c76d63..264c790 100644
--- a/readme.md
+++ b/readme.md
@@ -41,7 +41,8 @@ Task Time Tracker
 - [x] Check if next/previous is safe against overflows/underflows using https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html
 - [x] Confirm delete_task operation by show confirmation message on selected line (horizontally centered).
 - [x] Check totals update speedup using https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html
-	- For 1M entries, generic C code runs in 12.0ms while special approaches using builtins or SIMD takes around 9.5ms. Not worth the effort.
+	- For 1M entries, generic C code runs in 12.0ms while special approaches using builtins or SIMD takes around 9.5ms.
+	- Used optimization described [here](https://stackoverflow.com/questions/17580118/signed-saturated-add-of-64-bit-ints).
 - [x] Allow to jump to specific task by index number using key `g` and `G`;
 - [x] Move task to (using task_t tmp_task + memcpy) using key `m` and `M`;
 - [x] Rethink keys;