~drizzle-trunk/drizzle/development

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

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.

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

St, Fifth Floor, Boston, MA 02110-1301 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);

	}

}