From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Mon, 30 Aug 2021 12:50:21 +0000 (+0100)
Subject: fix RANGE function, reverse direction needed
X-Git-Tag: xlen-bcd~96
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=c7258236ed3bbd872c18064b7ae5cd56a64ffece;p=openpower-isa.git

fix RANGE function, reverse direction needed
---

diff --git a/src/openpower/decoder/helpers.py b/src/openpower/decoder/helpers.py
index 09f2324a..b1d9eb4c 100644
--- a/src/openpower/decoder/helpers.py
+++ b/src/openpower/decoder/helpers.py
@@ -19,17 +19,17 @@ MODS = trunc_rems
 """
 Links:
 * https://bugs.libre-soc.org/show_bug.cgi?id=324 - add trunc_div and trunc_rem
+* https://bugs.libre-soc.org/show_bug.cgi?id=671#c38 - RANGE (and bugfixes)
 """
 
 
 def RANGE(start, end):
     if start > end:
+        # reverse direction
         # auto-subtract-one (sigh) due to python range
-        end -= 1
-    else:
-        # auto-add-one (sigh) due to python range
-        end += 1
-    return range(start, end)
+        return range(start, end-1, -1)
+    # auto-add-one (sigh) due to python range
+    return range(start, end+1)
 
 
 def exts(value, bits):