X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=lib%2Fhashfunc.h;h=cc799476a87938e6349e786c6b6f4d72de9c2df1;hb=8107422b6cc0fda08e55218a3a79ff1580779a95;hp=d79e44ecfdaf695439a026496287ccab2e9ef76b;hpb=b0cbde12a98264c2629b52f618678e7f1eacf097;p=libucw.git

diff --git a/lib/hashfunc.h b/lib/hashfunc.h
index d79e44ec..cc799476 100644
--- a/lib/hashfunc.h
+++ b/lib/hashfunc.h
@@ -3,6 +3,9 @@
  *	routines
  *
  *	(c) 2002, Robert Spalek <robert@ucw.cz>
+ *
+ *	This software may be freely distributed and used according to the terms
+ *	of the GNU Lesser General Public License.
  */
 
 #ifndef _SHERLOCK_HASHFUNC_H
@@ -30,6 +33,13 @@ uns hash_block(const byte *str, uns len) CONST;
 
 uns hash_string_nocase(const byte *str) CONST;
 
-static inline uns CONST hash_int(uns x) { return 6442450967*x; }
+/*
+ *  We hash integers by multiplying by a reasonably large prime with
+ *  few ones in its binary form (to gave the compiler the possibility
+ *  of using shifts and adds on architectures where multiplication
+ *  instructions are slow).
+ */
+static inline uns CONST hash_int(uns x) { return 0x01008041*x; }
+static inline uns CONST hash_pointer(void *x) { return hash_int((uns)x); }
 
 #endif