Index: Objects/object.c
===================================================================
--- Objects/object.c	(révision 69444)
+++ Objects/object.c	(copie de travail)
@@ -1073,7 +1073,23 @@
 _Py_HashPointer(void *p)
 {
 #if SIZEOF_LONG >= SIZEOF_VOID_P
-	return (long)p;
+	unsigned long x = (unsigned long) p;
+	/* bottom 4 bits are likely to be 0, or at least non-significant;
+	   shift the remaining bits to the right so as to avoid excessive
+	   hash collisions for dicts and sets */
+	x = (x >> 4) + (x << (8*SIZEOF_LONG - 4));
+	if (x == (unsigned long) -1)
+		x = -2;
+	return x;
+/* 64-bit Windows has sizeof(long) == 4 and sizeof(void *) == 8 */
+#elif SIZEOF_VOID_P == SIZEOF_LONG*2
+	size_t y = (size_t)p;
+	unsigned long x;
+	x = (unsigned long) (y >> 8*SIZEOF_LONG) + (unsigned long) (y >> 4) +
+	    (unsigned long) (y << (8*SIZEOF_LONG - 4));
+	if (x == (unsigned long) -1)
+		x = -2;
+	return x;
 #else
 	/* convert to a Python long and hash that */
 	PyObject* longobj;