From: lkcl <lkcl@web>
Date: Sat, 25 Jun 2022 15:53:30 +0000 (+0100)
Subject: (no commit message)
X-Git-Tag: opf_rfc_ls005_v1~1528
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=63f095b29823628a9c89959358c9ea05e6080bd4;p=libreriscv.git

---

diff --git a/openpower/sv/vector_ops.mdwn b/openpower/sv/vector_ops.mdwn
index c510bcc4b..cdda04758 100644
--- a/openpower/sv/vector_ops.mdwn
+++ b/openpower/sv/vector_ops.mdwn
@@ -39,9 +39,9 @@ BM2-Form
 
 |0..5  |6..10|11..15|16..20|21-25|26|27..31| Form |
 |------|-----|------|------|-----|--|------|------|
-| PO   |  RS |   RA |   RB |mode |L |   XO | BM2-Form |
+| PO   |  RS |   RA |   RB |bm   |L |   XO | BM2-Form |
 
-* bmask RT,RA,RB,mode,L
+* bmask RT,RA,RB,bm,L
 
 The patterns within the pseudocode for AMD TBM and x86 BMI1 are
 as follows:
@@ -52,8 +52,10 @@ as follows:
 
 Thus it makes sense to create a single instruction
 that covers all of these.  A crucial addition that is essential
-for Scalable Vector usage however is the second mask parameter
-(RB).
+for Scalable Vector usage as Predicate Masks, is the second mask parameter
+(RB).  The additional paramater, L, if set, will leave bits of RA masked
+by RB unaltered, otherwise those bits are set to zero. Note that when `RB=0`
+then instead of reading from the register file the mask is set to all ones.
 
 Executable pseudocode demo: