From: lkcl <lkcl@web>
Date: Thu, 18 Feb 2021 16:13:37 +0000 (+0000)
Subject: (no commit message)
X-Git-Tag: convert-csv-opcode-to-binary~156
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=3f0ca5a2ee36c8983b88ae4e96933c3f8f8958e9;p=libreriscv.git

---

diff --git a/openpower/sv/bitmanip.mdwn b/openpower/sv/bitmanip.mdwn
index d56cd788c..403320efc 100644
--- a/openpower/sv/bitmanip.mdwn
+++ b/openpower/sv/bitmanip.mdwn
@@ -109,6 +109,17 @@ ops
 | NN | RA | RB  | RC  | 11    | 1  | 1110 110 |Rc| clmulh  |
 | NN | RA | RB  |     |       |    | NN11 110 |Rc| rsvd  |
 
+# count leading/trailing zeros with mask
+
+in v3.1 p105
+
+```
+count = 0
+do i = 0 to 63 if((RB)i=1) then do
+if((RS)i=1) then break end end count ← count + 1
+RA ← EXTZ64(count)
+```
+
 # bit to byte permute
 
 similar to matrix permute in RV bitmanip, which has XOR and OR variants