From: Gabriel Corona <gabriel.corona@loria.fr>
Date: Tue, 24 Jun 2014 11:29:28 +0000 (+0200)
Subject: [mc] Avoid loosing meaningful bits ot pair.p2 when hashing pointer pair
X-Git-Tag: v3_12~956^2~1^2~4
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/499a538e83b504eae266c45d7e3555df86996b1e

[mc] Avoid loosing meaningful bits ot pair.p2 when hashing pointer pair
---

diff --git a/src/mc/mc_compare.cpp b/src/mc/mc_compare.cpp
index 5a7c634617..6eaa3bf79f 100644
--- a/src/mc/mc_compare.cpp
+++ b/src/mc/mc_compare.cpp
@@ -29,9 +29,10 @@ typedef struct s_pointers_pair {
 namespace boost {
   template<>
   struct hash<s_pointers_pair> {
-    typedef uint64_t result_type;
+    typedef uintptr_t result_type;
     result_type operator()(s_pointers_pair const& x) const {
-      return (result_type) x.p1 ^ (result_type) x.p2 << 8;
+      return (result_type) x.p1 ^
+        ((result_type) x.p2 << 8 | (result_type) x.p2 >> (8*sizeof(uintptr_t) - 8));
     }
   };
 }