From: lkcl <lkcl@web>
Date: Fri, 29 Apr 2022 11:44:14 +0000 (+0100)
Subject: (no commit message)
X-Git-Tag: opf_rfc_ls005_v1~2545^2~1
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=60f1032fe907e0129cc510d43db334344785c26a;p=libreriscv.git

---

diff --git a/openpower/sv/biginteger/analysis.mdwn b/openpower/sv/biginteger/analysis.mdwn
index 3024a02e7..a19e6bdcc 100644
--- a/openpower/sv/biginteger/analysis.mdwn
+++ b/openpower/sv/biginteger/analysis.mdwn
@@ -492,6 +492,13 @@ allows the instruction to perform full parallel vector div/mod,
 or act in loop-back mode for big-int division by a scalar,
 or for a single scalar 128/64 div/mod.
 
+Again, just as with `sv.madded` and `sv.adde`, adventurous implementors
+may perform massively-wide DIV/MOD by transparently merging (fusing)
+the Vector element operations together, only inputting a single RC and
+outputting the last RC. Where efficient algorithms such as Goldschmidt
+are deployed internally this could dramatically reduce the cycle completion
+time for massive Vector DIV/MOD.
+
 Just as with `divdeu` on which this instruction is based an overflow
 detection is required.  When the divisor is too small compared to
 the dividend then the result may not fit into 64 bit.  Knuth's