(no commit message)

diff --git a/openpower/sv/bitmanip.mdwn b/openpower/sv/bitmanip.mdwn
index fb052cbfd210b49531030e8ce7110c05a1dd008b..b8e27037c97b3b76651f62e6a415bd77dee4c770 100644 (file)
--- a/openpower/sv/bitmanip.mdwn
+++ b/openpower/sv/bitmanip.mdwn
@@ -308,7 +308,11 @@ uint_xlen_t bmextrev(RA, RB, sh)
 
 # grev
 
-based on RV bitmanip, this is also known as a butterfly network
+based on RV bitmanip, this is also known as a butterfly network. however
+where a butterfly network allows setting of every crossbar setting in
+every row and every column, generalised-reverse (grev) only allows
+a per-row decision: every entry in the same row must either switch or
+not-switch.
 
 <img src="https://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Butterfly_Network.jpg/474px-Butterfly_Network.jpg" />