1 files changed, 70 insertions, 0 deletions
diff --git a/libelf/dl-hash.h b/libelf/dl-hash.h
new file mode 100644
index 00000000..c8e89626
--- /dev/null
+++ b/libelf/dl-hash.h
@@ -0,0 +1,70 @@
+/* Compute hash value for given string according to ELF standard.
+   Copyright (C) 1995-1998, 2002, 2004 Free Software Foundation, Inc.
+   Written by Ulrich Drepper <drepper@redhat.com>, 1995.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, version 2.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#ifndef _DL_HASH_H
+#define _DL_HASH_H	1
+
+
+/* This is the hashing function specified by the ELF ABI.  In the
+   first five operations no overflow is possible so we optimized it a
+   bit.  */
+static inline unsigned int
+__attribute__ ((__pure__))
+_dl_elf_hash (const char *name)
+{
+  const unsigned char *iname = (const unsigned char *) name;
+  unsigned int hash = (unsigned int) *iname++;
+  if (*iname != '\0')
+    {
+      hash = (hash << 4) + (unsigned int) *iname++;
+      if (*iname != '\0')
+	{
+	  hash = (hash << 4) + (unsigned int) *iname++;
+	  if (*iname != '\0')
+	    {
+	      hash = (hash << 4) + (unsigned int) *iname++;
+	      if (*iname != '\0')
+		{
+		  hash = (hash << 4) + (unsigned int) *iname++;
+		  while (*iname != '\0')
+		    {
+		      unsigned int hi;
+		      hash = (hash << 4) + (unsigned int) *iname++;
+		      hi = hash & 0xf0000000;
+
+		      /* The algorithm specified in the ELF ABI is as
+			 follows:
+
+			 if (hi != 0)
+			 hash ^= hi >> 24;
+
+			 hash &= ~hi;
+
+			 But the following is equivalent and a lot
+			 faster, especially on modern processors.  */
+
+		      hash ^= hi;
+		      hash ^= hi >> 24;
+		    }
+		}
+	    }
+	}
+    }
+  return hash;
+}
+
+#endif /* dl-hash.h */