From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Tue, 30 Apr 2019 01:58:21 +0000 (+0100)
Subject: minor code-shuffle on sqrt() fn
X-Git-Tag: ls180-24jan2020~1099
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=7541ca979084de96ebdf292e1baa0a03af64d3fc;p=ieee754fpu.git

minor code-shuffle on sqrt() fn
---

diff --git a/src/add/fsqrt.py b/src/add/fsqrt.py
index c88aea39..a87af61d 100644
--- a/src/add/fsqrt.py
+++ b/src/add/fsqrt.py
@@ -23,30 +23,24 @@ def sqrtsimple(num):
 def sqrt(num):
     D = num # D is input (from num)
     Q = 0
-    R = 0
-    r = 0 # remainder
+    R = 0 # remainder
     for i in range(64, -1, -1): # negative ranges are weird...
 
-        if (R>=0):
-
-            R = (R<<2)|((D>>(i+i))&3)
-            R = R-((Q<<2)|1) #/*-Q01*/
+        R = (R<<2)|((D>>(i+i))&3)
 
+        if R >= 0:
+            R -= ((Q<<2)|1) # -Q01
         else:
+            R += ((Q<<2)|3) # +Q11
 
-            R = (R<<2)|((D>>(i+i))&3)
-            R = R+((Q<<2)|3) #/*+Q11*/
-
-        if (R>=0):
-            Q = (Q<<1)|1 #/*new Q:*/
-        else:
-            Q = (Q<<1)|0 #/*new Q:*/
+        Q <<= 1
+        if R >= 0:
+            Q |= 1 # new Q
 
+    if R < 0:
+        R = R + ((Q<<1)|1)
 
-    if (R<0):
-        R = R+((Q<<1)|1)
-        r = R
-    return Q, r
+    return Q, R
 
 
 # grabbed these from unit_test_single (convenience, this is just experimenting)