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/*
* sign_ext.h
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef __WSUTIL_SIGN_EXT_H__
#define __WSUTIL_SIGN_EXT_H__
#include <glib.h>
/* sign extension routines */
static inline guint32
ws_sign_ext32(guint32 val, int no_of_bits)
{
g_assert (no_of_bits >= 0 && no_of_bits <= 32);
if ((no_of_bits == 0) || (no_of_bits == 32))
return val;
/*
* Don't shift signed values left; that's not valid in C99, at
* least, if the value is negative or if the shift count is
* the number of bits in the value - 1, and we might get
* compile-time or run-time complaints about that.
*/
if (val & (1U << (no_of_bits-1)))
val |= (0xFFFFFFFFU << no_of_bits);
return val;
}
static inline guint64
ws_sign_ext64(guint64 val, int no_of_bits)
{
g_assert (no_of_bits >= 0 && no_of_bits <= 64);
if ((no_of_bits == 0) || (no_of_bits == 64))
return val;
/*
* Don't shift signed values left; that's not valid in C99, at
* least, if the value is negative or if the shift count is
* the number of bits in the value - 1, and we might get
* compile-time or run-time complaints about that.
*/
if (val & (G_GUINT64_CONSTANT(1) << (no_of_bits-1)))
val |= (G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF) << no_of_bits);
return val;
}
/*
static inline guint64
ws_sign_ext64(guint64 val, int no_of_bits)
{
gint64 sval = (val << (64 - no_of_bits));
return (guint64) (sval >> (64 - no_of_bits));
}
*/
#endif /* __WSUTIL_SIGN_EXT_H__ */
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