From 6e5a49de25f294a184d04a0e5051b27e0f3f88d5 Mon Sep 17 00:00:00 2001
From: Neale Pickett <neale@lanl.gov>
Date: Mon, 21 Apr 2008 12:19:22 -0600
Subject: [PATCH] Make sum() macro a little easier to understand

---
 magic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/magic.c b/magic.c
index bc1b326..c59add1 100644
--- a/magic.c
+++ b/magic.c
@@ -34,8 +34,8 @@
 
 #define sum(a, b, v, m)     \
   if (b < -v) {             \
-    a = -1 * (b + v);       \
     v *= -1;                \
+    a = v - b;              \
   } else if (m - b <= v) {  \
     v *= -1;                \
     a = m - (m - b) + v;    \