From: lkcl <lkcl@web>
Date: Sat, 5 Oct 2019 09:31:52 +0000 (+0100)
Subject: (no commit message)
X-Git-Tag: convert-csv-opcode-to-binary~3896
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=8d84db3e5788078924e399c5fdbc37f71f4ee5e7;p=libreriscv.git

---

diff --git a/simple_v_extension/vector_ops.mdwn b/simple_v_extension/vector_ops.mdwn
index e45b9642f..71d45fbfb 100644
--- a/simple_v_extension/vector_ops.mdwn
+++ b/simple_v_extension/vector_ops.mdwn
@@ -131,6 +131,16 @@ Pseudocode in c:
         return result;
     }
 
+## Vector Normalisation (not included)
+
+Vector normalisation may be performed through dot product, recip square root and multiplication:
+
+    fdot F3, F1, F1 # vector dot with self
+    rcpsqrta F3, F3
+    fscale,0 F2, F3, F1
+
+Or it may be performed through VLEN (Vector length) and division.
+
 ## Vector length
 
 * rd=scalar, vs1=vec (SUBVL=1)
@@ -144,6 +154,8 @@ The scalar length of a vector:
 
     sqrt(x[0]^2 + x[1]^2 + ...).
 
+One option is for this to be a macro op fusion sequence, with inverse-sqrt also being a second macro op sequence suitable for normalisation.
+
 ## Vector distance
 
 * VDIST rd, vs1, vs2