From 74f0cc0d08b9de219e60a085c0a6bb8b482c404f Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Sat, 11 Jul 2020 11:13:09 +0100
Subject: [PATCH] add overflow to mullw

---
 openpower/isa/fixedarith.mdwn | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/openpower/isa/fixedarith.mdwn b/openpower/isa/fixedarith.mdwn
index 65425d2ef..4447bd80f 100644
--- a/openpower/isa/fixedarith.mdwn
+++ b/openpower/isa/fixedarith.mdwn
@@ -350,6 +350,8 @@ Pseudo-code:
 
     prod[0:63] <- MULS((RA)[32:63], (RB)[32:63])
     RT <- prod
+    overflow <- (prod[32:64] != 0x0000_0000) &
+                (prod[32:64] != 0xffff_ffff)
 
 Special Registers Altered:
 
-- 
2.30.2