From 6251e5d5257e525b54c7722ba09e2683339f13a3 Mon Sep 17 00:00:00 2001
From: lkcl <lkcl@web>
Date: Tue, 19 Apr 2022 13:07:43 +0100
Subject: [PATCH]

---
 openpower/isa/svfixedarith.mdwn | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/openpower/isa/svfixedarith.mdwn b/openpower/isa/svfixedarith.mdwn
index 23fad0402..e51e292b2 100644
--- a/openpower/isa/svfixedarith.mdwn
+++ b/openpower/isa/svfixedarith.mdwn
@@ -30,6 +30,17 @@ Special Registers Altered:
 
     None
 
+# Twin Multiply and Add  Doubleword
+
+<!-- SVP64: RC-as-source and RC-as-dest have separate EXTRA2 -->
+<!-- RT, RA have EXTRA2 marking. RB is always scalar (r0-31) -->
+* maddx RT,RA,RB,RC
+
+    prod[0:127] <- (RA) * (RB)
+    sum[0:127] <- EXTZ(RC) + prod
+    RT <- sum[64:127]
+    RC <- sum[0:63]
+
 # Twin Multiply and Subtract Doubleword
 
 * msubx RT,RA,RB,RC
-- 
2.30.2