From a92fa257afdd8027bd7bb517f7b9dd2f77ed03fe Mon Sep 17 00:00:00 2001
From: Patrick Niklaus <patrick.niklaus@student.kit.edu>
Date: Mon, 6 Mar 2017 23:53:52 +0000
Subject: [PATCH] Fix off-by-one in fallback MSB function

---
 include/util/msb.hpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/util/msb.hpp b/include/util/msb.hpp
index fda09f2f0..8bc458f3c 100644
--- a/include/util/msb.hpp
+++ b/include/util/msb.hpp
@@ -22,7 +22,8 @@ template <typename T> std::size_t msb(T value)
         value >>= 1u;
         msb++;
     }
-    return msb;
+    BOOST_ASSERT(msb > 0);
+    return msb-1;
 }
 
 #if (defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)) && __x86_64__