ed0b19b94b
There are protocols out there that have 64-bit wide bit mask fields, so make the internal representation and bitfield decoders 64-bit aware. For this, the ws_ctz() fallback and bits_count_ones() have to be tweaked slightly. Change-Id: I19237b954a69c9e6c55864f281993c1e8731a233 Reviewed-on: https://code.wireshark.org/review/4158 Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com> Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org> Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com> Reviewed-by: Michael Mann <mmann78@netscape.net>
61 lines
1.6 KiB
C
61 lines
1.6 KiB
C
/*
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* bitz_ctz.h
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#ifndef __WSUTIL_BITS_CTZ_H__
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#define __WSUTIL_BITS_CTZ_H__
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#include <glib.h>
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#if defined(__GNUC__) && ((__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4))
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static inline int
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ws_ctz(guint64 x)
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{
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return __builtin_ctzll(x);
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}
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#else
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static inline int
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__ws_ctz32(guint32 x)
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{
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/* From http://graphics.stanford.edu/~seander/bithacks.html#ZerosOnRightMultLookup */
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static const int table[32] = {
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0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
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31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
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};
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return table[((guint32)((x & -(gint32)x) * 0x077CB531U)) >> 27];
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}
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static inline int
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ws_ctz(guint64 x)
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{
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guint32 hi = x >> 32;
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guint32 lo = (guint32) x;
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if (lo == 0)
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return 32 + __ws_ctz32(hi);
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else
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return __ws_ctz32(lo);
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}
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#endif
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#endif /* __WSUTIL_BITS_CTZ_H__ */
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