forked from osmocom/wireshark
69 lines
1.6 KiB
C
69 lines
1.6 KiB
C
/** @file
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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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* SPDX-License-Identifier: GPL-2.0-or-later
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*/
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#ifndef __WSUTIL_SIGN_EXT_H__
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#define __WSUTIL_SIGN_EXT_H__
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#include <glib.h>
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#include <wsutil/ws_assert.h>
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/* sign extension routines */
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static inline guint32
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ws_sign_ext32(guint32 val, int no_of_bits)
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{
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ws_assert (no_of_bits >= 0 && no_of_bits <= 32);
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if ((no_of_bits == 0) || (no_of_bits == 32))
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return val;
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/*
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* Don't shift signed values left; that's not valid in C99, at
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* least, if the value is negative or if the shift count is
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* the number of bits in the value - 1, and we might get
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* compile-time or run-time complaints about that.
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*/
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if (val & (1U << (no_of_bits-1)))
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val |= (0xFFFFFFFFU << no_of_bits);
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return val;
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}
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static inline guint64
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ws_sign_ext64(guint64 val, int no_of_bits)
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{
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ws_assert (no_of_bits >= 0 && no_of_bits <= 64);
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if ((no_of_bits == 0) || (no_of_bits == 64))
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return val;
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/*
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* Don't shift signed values left; that's not valid in C99, at
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* least, if the value is negative or if the shift count is
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* the number of bits in the value - 1, and we might get
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* compile-time or run-time complaints about that.
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*/
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if (val & (G_GUINT64_CONSTANT(1) << (no_of_bits-1)))
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val |= (G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF) << no_of_bits);
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return val;
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}
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/*
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static inline guint64
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ws_sign_ext64(guint64 val, int no_of_bits)
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{
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gint64 sval = (val << (64 - no_of_bits));
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return (guint64) (sval >> (64 - no_of_bits));
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}
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*/
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#endif /* __WSUTIL_SIGN_EXT_H__ */
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