X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=hv.h;h=a9fc9fb9af42cbca8847592fe8c8d050596b8c8b;hb=e42c74e1bbeb8832945ac76bd2905217353ae440;hp=f8cf2b968f0cc524b40f10565d57c582eab4c06c;hpb=da58a35d3e499cdd492619302eb044ac1841788f;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/hv.h b/hv.h
index f8cf2b9..a9fc9fb 100644
--- a/hv.h
+++ b/hv.h
@@ -1,6 +1,6 @@
 /*    hv.h
  *
- *    Copyright (c) 1991-2000, Larry Wall
+ *    Copyright (c) 1991-2001, Larry Wall
  *
  *    You may distribute under the terms of either the GNU General Public
  *    License or the Artistic License, as specified in the README file.
@@ -43,14 +43,22 @@ struct xpvhv {
 };
 
 /* hash a key */
+/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins */
+/* from requirements by Colin Plumb. */
+/* (http://burtleburtle.net/bob/hash/doobs.html) */
 #define PERL_HASH(hash,str,len) \
      STMT_START	{ \
 	register const char *s_PeRlHaSh = str; \
 	register I32 i_PeRlHaSh = len; \
 	register U32 hash_PeRlHaSh = 0; \
-	while (i_PeRlHaSh--) \
-	    hash_PeRlHaSh = hash_PeRlHaSh * 33 + *s_PeRlHaSh++; \
-	(hash) = hash_PeRlHaSh + (hash_PeRlHaSh>>5); \
+	while (i_PeRlHaSh--) { \
+	    hash_PeRlHaSh += *s_PeRlHaSh++; \
+	    hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
+	    hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
+	} \
+	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
+	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
+	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
     } STMT_END
 
 /*