From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Tue, 31 Aug 2021 11:19:49 +0000 (+0100)
Subject: adjusted popcntw to simplify by using temp vars
X-Git-Tag: xlen-bcd~56
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=cc990388b1f29c87f4d7ff53edbef9d34312b6f8;p=openpower-isa.git

adjusted popcntw to simplify by using temp vars
https://bugs.libre-soc.org/show_bug.cgi?id=671#c50
e <- (XLEN/2)-1
s <- i*XLEN/2
---

diff --git a/openpower/isa/fixedlogical.mdwn b/openpower/isa/fixedlogical.mdwn
index c301678c..3ab769d5 100644
--- a/openpower/isa/fixedlogical.mdwn
+++ b/openpower/isa/fixedlogical.mdwn
@@ -333,12 +333,14 @@ X-Form
 
 Pseudo-code:
 
+    e <- (XLEN/2)-1
     do i = 0 to 1
+       s <- i*XLEN/2
        n <-  0
-       do j = 0 to ((XLEN/2)-1)
-          if (RS)[(i*(XLEN/2))+j] = 1 then
+       do j = 0 to e
+          if (RS)[s+j] = 1 then
               n <- n+1
-       RA[(i*(XLEN/2)):(i*(XLEN/2))+((XLEN/2)-1)] <- n
+       RA[s:s+e] <- n
 
 Special Registers Altered: