From: lkcl <lkcl@web>
Date: Thu, 27 Apr 2023 18:55:31 +0000 (+0100)
Subject: (no commit message)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=0d05ab3b21846ce13cee2b022625d79ee8fcddbf;p=libreriscv.git

---

diff --git a/openpower/sv/twin_butterfly.mdwn b/openpower/sv/twin_butterfly.mdwn
index 7aa8f3200..a8983dbb5 100644
--- a/openpower/sv/twin_butterfly.mdwn
+++ b/openpower/sv/twin_butterfly.mdwn
@@ -40,15 +40,16 @@ BF-Form
 
 Pseudo-code:
 
-    RT2 <- RT + 1
+```
     sum <- (RA) + (RB)
     diff <- (RA) - (RB)
-    prod1 <- MUL(RC, sum)
-    prod2 <- MUL(RC, diff)
-    res1 <- ROTL64(prod1, SH)
+    prod1 <- MUL(RC, sum)   # TODO: pick hi-half
+    prod2 <- MUL(RC, diff)  # TODO: pick hi-half
+    res1 <- ROTL64(prod1, SH) # TODO shift the other way (63-SH?)
     res2 <- ROTL64(prod2, SH)
-    RT <- (RT) + res1
-    RT2 <- (RT2) + res2
+    RT <- res1
+    RS <- res2
+```
 
 Special Registers Altered: