diff options
| -rw-r--r-- | epan/proto.c | 18 | ||||
| -rw-r--r-- | wsutil/Makefile.common | 1 | ||||
| -rw-r--r-- | wsutil/bits_ctz.h | 48 |
3 files changed, 52 insertions, 15 deletions
diff --git a/epan/proto.c b/epan/proto.c index bd81825512..07c775bd01 100644 --- a/epan/proto.c +++ b/epan/proto.c @@ -29,6 +29,8 @@ #include <ctype.h> #include <glib.h> #include <float.h> + +#include <wsutil/bits_ctz.h> #include <wsutil/swar.h> #include "packet.h" @@ -5603,21 +5605,7 @@ fill_label_number64(field_info *fi, gchar *label_str, gboolean is_signed) int hfinfo_bitshift(const header_field_info *hfinfo) { - const guint32 bitmask = hfinfo->bitmask; - -#if defined(__GNUC__) && ((__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)) - g_assert(bitmask != 0); - - return __builtin_ctz(bitmask); -#else - /* From http://graphics.stanford.edu/~seander/bithacks.html#ZerosOnRightMultLookup */ - static const int table[32] = { - 0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8, - 31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9 - }; - - return table[((guint32)((bitmask & -(gint32)bitmask) * 0x077CB531U)) >> 27]; -#endif + return ws_ctz(hfinfo->bitmask); } int diff --git a/wsutil/Makefile.common b/wsutil/Makefile.common index 7332d97d8e..4d2ab79376 100644 --- a/wsutil/Makefile.common +++ b/wsutil/Makefile.common @@ -62,6 +62,7 @@ LIBWSUTIL_SRC = \ # Header files that are not generated from other files LIBWSUTIL_INCLUDES = \ aes.h \ + bits_ctz.h \ crash_info.h \ crc6.h \ crc7.h \ diff --git a/wsutil/bits_ctz.h b/wsutil/bits_ctz.h new file mode 100644 index 0000000000..7fa9cd87ad --- /dev/null +++ b/wsutil/bits_ctz.h @@ -0,0 +1,48 @@ +/* + * bitz_ctz.h + * + * $Id$ + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * 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; either version 2 + * of the License, or (at your option) any later version. + * + * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#ifndef __WSUTIL_BITS_CTZ_H__ +#define __WSUTIL_BITS_CTZ_H__ + +#include <glib.h> + +static inline int +ws_ctz(guint32 x) +{ +#if defined(__GNUC__) && ((__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)) + g_assert(x != 0); + + return __builtin_ctz(x); +#else + /* From http://graphics.stanford.edu/~seander/bithacks.html#ZerosOnRightMultLookup */ + static const int table[32] = { + 0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8, + 31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9 + }; + + return table[((guint32)((x & -(gint32)x) * 0x077CB531U)) >> 27]; +#endif +} + +#endif /* __WSUTIL_BITS_CTZ_H__ */ |