mariadb/storage/innobase/include/ut0byte.ic

/*****************************************************************************

Copyright (c) 1994, 2009, Innobase Oy. All Rights Reserved.

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 of the License.

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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

*****************************************************************************/

/**************************************************************//**
@file include/ut0byte.ic
Utilities for byte operations

Created 5/30/1994 Heikki Tuuri
*******************************************************************/

/*******************************************************//**
Creates a 64-bit integer out of two 32-bit integers.
@return	created dulint */
UNIV_INLINE
ib_uint64_t
ut_ull_create(
/*==========*/
	ulint	high,	/*!< in: high-order 32 bits */
	ulint	low)	/*!< in: low-order 32 bits */
{
	ut_ad(high <= ULINT32_MASK);
	ut_ad(low <= ULINT32_MASK);
	return(((ib_uint64_t) high) << 32 | low);
}

/********************************************************//**
Rounds a 64-bit integer downward to a multiple of a power of 2.
@return	rounded value */
UNIV_INLINE
ib_uint64_t
ut_uint64_align_down(
/*=================*/
	ib_uint64_t	 n,		/*!< in: number to be rounded */
	ulint		 align_no)	/*!< in: align by this number
					which must be a power of 2 */
{
	ut_ad(align_no > 0);
	ut_ad(ut_is_2pow(align_no));

	return(n & ~((ib_uint64_t) align_no - 1));
}

/********************************************************//**
Rounds ib_uint64_t upward to a multiple of a power of 2.
@return	rounded value */
UNIV_INLINE
ib_uint64_t
ut_uint64_align_up(
/*===============*/
	ib_uint64_t	 n,		/*!< in: number to be rounded */
	ulint		 align_no)	/*!< in: align by this number
					which must be a power of 2 */
{
	ib_uint64_t	align_1 = (ib_uint64_t) align_no - 1;

	ut_ad(align_no > 0);
	ut_ad(ut_is_2pow(align_no));

	return((n + align_1) & ~align_1);
}

/*********************************************************//**
The following function rounds up a pointer to the nearest aligned address.
@return	aligned pointer */
UNIV_INLINE
void*
ut_align(
/*=====*/
	const void*	ptr,		/*!< in: pointer */
	ulint		align_no)	/*!< in: align by this number */
{
	ut_ad(align_no > 0);
	ut_ad(((align_no - 1) & align_no) == 0);
	ut_ad(ptr);

	ut_ad(sizeof(void*) == sizeof(ulint));

	return((void*)((((ulint)ptr) + align_no - 1) & ~(align_no - 1)));
}

/*********************************************************//**
The following function rounds down a pointer to the nearest
aligned address.
@return	aligned pointer */
UNIV_INLINE
void*
ut_align_down(
/*==========*/
	const void*	ptr,		/*!< in: pointer */
	ulint		align_no)	/*!< in: align by this number */
{
	ut_ad(align_no > 0);
	ut_ad(((align_no - 1) & align_no) == 0);
	ut_ad(ptr);

	ut_ad(sizeof(void*) == sizeof(ulint));

	return((void*)((((ulint)ptr)) & ~(align_no - 1)));
}

/*********************************************************//**
The following function computes the offset of a pointer from the nearest
aligned address.
@return	distance from aligned pointer */
UNIV_INLINE
ulint
ut_align_offset(
/*============*/
	const void*	ptr,		/*!< in: pointer */
	ulint		align_no)	/*!< in: align by this number */
{
	ut_ad(align_no > 0);
	ut_ad(((align_no - 1) & align_no) == 0);
	ut_ad(ptr);

	ut_ad(sizeof(void*) == sizeof(ulint));

	return(((ulint)ptr) & (align_no - 1));
}

/*****************************************************************//**
Gets the nth bit of a ulint.
@return	TRUE if nth bit is 1; 0th bit is defined to be the least significant */
UNIV_INLINE
ibool
ut_bit_get_nth(
/*===========*/
	ulint	a,	/*!< in: ulint */
	ulint	n)	/*!< in: nth bit requested */
{
	ut_ad(n < 8 * sizeof(ulint));
#if TRUE != 1
# error "TRUE != 1"
#endif
	return(1 & (a >> n));
}

/*****************************************************************//**
Sets the nth bit of a ulint.
@return	the ulint with the bit set as requested */
UNIV_INLINE
ulint
ut_bit_set_nth(
/*===========*/
	ulint	a,	/*!< in: ulint */
	ulint	n,	/*!< in: nth bit requested */
	ibool	val)	/*!< in: value for the bit to set */
{
	ut_ad(n < 8 * sizeof(ulint));
#if TRUE != 1
# error "TRUE != 1"
#endif
	if (val) {
		return(((ulint) 1 << n) | a);
	} else {
		return(~((ulint) 1 << n) & a);
	}
}