forked from xuos/xiuos
				
			
		
			
				
	
	
		
			67 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			67 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
 | |
| * Copyright (c) 2020 AIIT XUOS Lab
 | |
| * XiUOS is licensed under Mulan PSL v2.
 | |
| * You can use this software according to the terms and conditions of the Mulan PSL v2.
 | |
| * You may obtain a copy of Mulan PSL v2 at:
 | |
| *        http://license.coscl.org.cn/MulanPSL2
 | |
| * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 | |
| * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 | |
| * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 | |
| * See the Mulan PSL v2 for more details.
 | |
| */
 | |
| 
 | |
| /**
 | |
| * @file:    bitmap.c
 | |
| * @brief:   calculate the highest priority
 | |
| * @version: 1.0
 | |
| * @author:  AIIT XUOS Lab
 | |
| * @date:    2020/3/15
 | |
| *
 | |
| */
 | |
| 
 | |
| #include <xs_assign.h>
 | |
| 
 | |
| const uint8 LeaderZeroCount[] =
 | |
| {
 | |
|     8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
 | |
|     3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
 | |
|     2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
 | |
|     2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
 | |
|     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 | |
|     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 | |
|     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 | |
|     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 | |
|     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
|     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
|     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
|     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
|     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
|     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
|     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
|     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 | |
| };
 | |
| 
 | |
| int PrioCaculate(uint32 bitmap)
 | |
| {
 | |
|     if (bitmap & 0xff000000)
 | |
|     {
 | |
|         return 31 - LeaderZeroCount[(bitmap & 0xff000000) >> 24];
 | |
|     }
 | |
|     else if (bitmap & 0xff0000)
 | |
|     {
 | |
|         return 23 - LeaderZeroCount[(bitmap & 0xff0000) >> 16];
 | |
|     }
 | |
|     else if (bitmap & 0xff00)
 | |
|     {
 | |
|         return 15 - LeaderZeroCount[(bitmap & 0xff00) >> 8];
 | |
|     }
 | |
|     else if (bitmap & 0xff)
 | |
|     {
 | |
|         return 7 - LeaderZeroCount[bitmap & 0xff];
 | |
|     }
 | |
|     else
 | |
|     {
 | |
|         return 0;
 | |
|     }
 | |
| }
 |