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 /* SPDX-License-Identifier: BSD-2-Clause */
 
 /**
  * @file
  *
  * @ingroup RTEMSScorePriorityBitmap
  *
  * @brief This header file provides interfaces of the
  *   @ref RTEMSScorePriorityBitmap which are only used by the implementation.
  */
 
 /*
  *  COPYRIGHT (c) 1989-2010.
  *  On-Line Applications Research Corporation (OAR).
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef _RTEMS_SCORE_PRIORITYBITMAPIMPL_H
 #define _RTEMS_SCORE_PRIORITYBITMAPIMPL_H
 
 #include <rtems/score/prioritybitmap.h>
 
 #include <string.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /**
  * @addtogroup RTEMSScorePriority
  *
  * @{
  */
 
 /**
  *  This table is used by the generic bitfield routines to perform
  *  a highly optimized bit scan without the use of special CPU
  *  instructions.
  */
 extern const unsigned char _Bitfield_Leading_zeros[256];
 
 /**
  * @brief Returns the bit number of the first bit set in the specified value.
  *
  * The correspondence between the bit number and actual bit position is CPU
  * architecture dependent.  The search for the first bit set may run from most
  * to least significant bit or vice-versa.
  *
  * @param value The value to bit scan.
  *
  * @return The bit number of the first bit set.
  *
  * @see _Priority_Bits_index() and _Priority_Mask().
  */
 static inline unsigned int _Bitfield_Find_first_bit(
   unsigned int value
 )
 {
   unsigned int bit_number;
 
 #if ( CPU_USE_GENERIC_BITFIELD_CODE == FALSE )
   _CPU_Bitfield_Find_first_bit( value, bit_number );
 #elif defined(__GNUC__)
   bit_number = (unsigned int) __builtin_clz( value )
     - __SIZEOF_INT__ * __CHAR_BIT__ + 16;
 #else
   if ( value < 0x100 ) {
     bit_number = _Bitfield_Leading_zeros[ value ] + 8;
   } else { \
     bit_number = _Bitfield_Leading_zeros[ value >> 8 ];
   }
 #endif
 
   return bit_number;
 }
 
 /**
  * @brief Returns the priority bit mask for the specified major or minor bit
  * number.
  *
  * @param bit_number The bit number for which we need a mask.
  *
  * @return The priority bit mask.
  */
 static inline Priority_bit_map_Word _Priority_Mask(
   unsigned int bit_number
 )
 {
 #if ( CPU_USE_GENERIC_BITFIELD_CODE == FALSE )
   return _CPU_Priority_Mask( bit_number );
 #else
   return (Priority_bit_map_Word) ( 0x8000u >> bit_number );
 #endif
 }
 
 /**
  * @brief Returns the bit index position for the specified major or minor bit
  * number.
  *
  * @param bit_number The bit number for which we need an index.
  *
  * @return The corresponding array index into the priority bit map.
  */
 static inline unsigned int _Priority_Bits_index(
   unsigned int bit_number
 )
 {
 #if ( CPU_USE_GENERIC_BITFIELD_CODE == FALSE )
   return _CPU_Priority_bits_index( bit_number );
 #else
   return bit_number;
 #endif
 }
 
 /**
  * @brief Returns the major portion of the_priority.
  *
  * @param the_priority The priority of which we want the major portion.
  *
  * @return The major portion of the priority.
  */
 static inline unsigned int _Priority_Major( unsigned int the_priority )
 {
   return the_priority / 16;
 }
 
 /**
  * @brief Returns the minor portion of the_priority.
  *
  * @param the_priority The priority of which we want the minor portion.
  *
  * @return The minor portion of the priority.
  */
 static inline unsigned int _Priority_Minor( unsigned int the_priority )
 {
   return the_priority % 16;
 }
 
 /**
  * @brief Initializes a bit map.
  *
  * @param[out] bit_map The bit map to initialize.
  */
 static inline void _Priority_bit_map_Initialize(
   Priority_bit_map_Control *bit_map
 )
 {
   memset( bit_map, 0, sizeof( *bit_map ) );
 }
 
 /**
  * @brief Adds Priority queue bit map information.
  *
  * Priority Queue implemented by bit map.
  *
  * @param[out] bit_map The bit map to be altered by @a bit_map_info.
  * @param bit_map_info The information with which to alter @a bit_map.
  */
 static inline void _Priority_bit_map_Add (
   Priority_bit_map_Control     *bit_map,
   Priority_bit_map_Information *bit_map_info
 )
 {
   *bit_map_info->minor |= bit_map_info->ready_minor;
   bit_map->major_bit_map |= bit_map_info->ready_major;
 }
 
 /**
  * @brief Removes Priority queue bit map information.
  *
  * Priority Queue implemented by bit map.
  *
  * @param[out] bit_map The bit map to be altered by @a bit_map_info.
  * @param bit_map_info The information with which to alter @a bit_map.
  */
 static inline void _Priority_bit_map_Remove (
   Priority_bit_map_Control     *bit_map,
   Priority_bit_map_Information *bit_map_info
 )
 {
   *bit_map_info->minor &= bit_map_info->block_minor;
   if ( *bit_map_info->minor == 0 )
     bit_map->major_bit_map &= bit_map_info->block_major;
 }
 
 /**
  * @brief Gets highest portion of Priority queue bit map.
  *
  * @param bit_map The bitmap to get the highest portion from.
  *
  * @return The highest portion of the bitmap.
  */
 static inline unsigned int _Priority_bit_map_Get_highest(
   const Priority_bit_map_Control *bit_map
 )
 {
   unsigned int minor;
   unsigned int major;
 
   major = _Bitfield_Find_first_bit( bit_map->major_bit_map );
   minor = _Bitfield_Find_first_bit( bit_map->bit_map[ major ] );
 
   return (_Priority_Bits_index( major ) << 4) +
           _Priority_Bits_index( minor );
 }
 
 /**
  * @brief Checks if the Priority queue bit map is empty.
  *
  * @param bit_map The bit map of which to check if it is empty.
  *
  * @retval true The Priority queue bit map is empty
  * @retval false The Priority queue bit map is not empty.
  */
 static inline bool _Priority_bit_map_Is_empty(
   const Priority_bit_map_Control *bit_map
 )
 {
   return bit_map->major_bit_map == 0;
 }
 
 /**
  * @brief Initializes the bit map information.
  *
  * @param bit_map The bit map for the initialization of the bit
  *      map information.
  * @param[out] bit_map_info The bit map information to initialize.
  * @param new_priority The new priority for the initialization
  *      of the bit map information.
  */
 static inline void _Priority_bit_map_Initialize_information(
   Priority_bit_map_Control     *bit_map,
   Priority_bit_map_Information *bit_map_info,
   unsigned int                  new_priority
 )
 {
   unsigned int major;
   unsigned int minor;
   Priority_bit_map_Word mask;
 
   major = _Priority_Major( new_priority );
   minor = _Priority_Minor( new_priority );
 
   bit_map_info->minor = &bit_map->bit_map[ _Priority_Bits_index( major ) ];
 
   mask = _Priority_Mask( major );
   bit_map_info->ready_major = mask;
   bit_map_info->block_major = (Priority_bit_map_Word) ~mask;
 
   mask = _Priority_Mask( minor );
   bit_map_info->ready_minor = mask;
   bit_map_info->block_minor = (Priority_bit_map_Word) ~mask;
 }
 
 /** @} */
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif
 /* end of include file */

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