add comment on special operations

diff --git a/src/add/nmigen_add_experiment.py b/src/add/nmigen_add_experiment.py
index f6e10fe5437f9bde26a61ce22aceb6f427ff72fb..38af9437579077f8b233f8d65340d22d45e61ae9 100644 (file)
--- a/src/add/nmigen_add_experiment.py
+++ b/src/add/nmigen_add_experiment.py
@@ -244,6 +244,8 @@ class FPADD:
 
             # ******
             # special cases: NaNs, infs, zeros, denormalised
+            # NOTE: some of these are unique to add.  see "Special Operations"
+            # https://steve.hollasch.net/cgindex/coding/ieeefloat.html
 
             with m.State("special_cases"):