mirror of
				https://sourceware.org/git/glibc.git
				synced 2025-10-30 10:45:40 +03:00 
			
		
		
		
	
		
			
				
	
	
		
			101 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			101 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Macros to swap the order of bytes in integer values.
 | |
|    Copyright (C) 1997-2017 Free Software Foundation, Inc.
 | |
|    This file is part of the GNU C Library.
 | |
| 
 | |
|    The GNU C Library is free software; you can redistribute it and/or
 | |
|    modify it under the terms of the GNU Lesser General Public
 | |
|    License as published by the Free Software Foundation; either
 | |
|    version 2.1 of the License, or (at your option) any later version.
 | |
| 
 | |
|    The GNU C Library 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
 | |
|    Lesser General Public License for more details.
 | |
| 
 | |
|    You should have received a copy of the GNU Lesser General Public
 | |
|    License along with the GNU C Library; if not, see
 | |
|    <http://www.gnu.org/licenses/>.  */
 | |
| 
 | |
| #if !defined _BYTESWAP_H && !defined _NETINET_IN_H && !defined _ENDIAN_H
 | |
| # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
 | |
| #endif
 | |
| 
 | |
| #ifndef _BITS_BYTESWAP_H
 | |
| #define _BITS_BYTESWAP_H 1
 | |
| 
 | |
| /* Swap bytes in 16 bit value.  */
 | |
| #define __bswap_constant_16(x) \
 | |
|      ((unsigned short int)((((x) >> 8) & 0xff) | (((x) & 0xff) << 8)))
 | |
| 
 | |
| /* Get __bswap_16.  */
 | |
| #include <bits/byteswap-16.h>
 | |
| 
 | |
| /* Swap bytes in 32 bit value.  */
 | |
| #define __bswap_constant_32(x) \
 | |
|      ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) |		      \
 | |
|       (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24))
 | |
| 
 | |
| #if defined __GNUC__ && __GNUC__ >= 2
 | |
| # define __bswap_32(x) \
 | |
|      (__extension__							      \
 | |
|       ({ unsigned int __v, __x = (x);					      \
 | |
| 	 if (__builtin_constant_p (x))					      \
 | |
| 	   __v = __bswap_constant_32 (__x);				      \
 | |
| 	 else								      \
 | |
| 	   __asm__ __volatile__ ("shl %0 = %1, 32 ;;"			      \
 | |
| 				 "mux1 %0 = %0, @rev ;;"		      \
 | |
| 				 : "=r" (__v)				      \
 | |
| 				 : "r" ((unsigned int) (__x)));		      \
 | |
| 	 __v; }))
 | |
| #else
 | |
| static __inline unsigned int
 | |
| __bswap_32 (unsigned int __bsx)
 | |
| {
 | |
|   return __bswap_constant_32 (__bsx);
 | |
| }
 | |
| #endif
 | |
| 
 | |
| 
 | |
| /* Swap bytes in 64 bit value.  */
 | |
| #if defined __GNUC__ && __GNUC__ >= 2
 | |
| # define __bswap_constant_64(x) \
 | |
|      (__extension__ ((((x) & 0xff00000000000000ul) >> 56)		      \
 | |
| 		     | (((x) & 0x00ff000000000000ul) >>  40)		      \
 | |
| 		     | (((x) & 0x0000ff0000000000ul) >> 24)		      \
 | |
| 		     | (((x) & 0x000000ff00000000ul) >> 8)		      \
 | |
| 		     | (((x) & 0x00000000ff000000ul) << 8)		      \
 | |
| 		     | (((x) & 0x0000000000ff0000ul) << 24)		      \
 | |
| 		     | (((x) & 0x000000000000ff00ul) << 40)		      \
 | |
| 		     | (((x) & 0x00000000000000fful) << 56)))
 | |
| 
 | |
| # define __bswap_64(x) \
 | |
|      (__extension__							      \
 | |
|       ({ unsigned long int __v, __x = (x);				      \
 | |
| 	 if (__builtin_constant_p (x))					      \
 | |
| 	   __v = __bswap_constant_64 (__x);				      \
 | |
| 	 else								      \
 | |
| 	   __asm__ __volatile__ ("mux1 %0 = %1, @rev ;;"		      \
 | |
| 				 : "=r" (__v)				      \
 | |
| 				 : "r" ((unsigned long int) (__x)));	      \
 | |
| 	 __v; }))
 | |
| 
 | |
| #else
 | |
| # define __bswap_constant_64(x) \
 | |
|      ((((x) & 0xff00000000000000ul) >> 56)				      \
 | |
|       | (((x) & 0x00ff000000000000ul) >>  40)				      \
 | |
|       | (((x) & 0x0000ff0000000000ul) >> 24)				      \
 | |
|       | (((x) & 0x000000ff00000000ul) >> 8)				      \
 | |
|       | (((x) & 0x00000000ff000000ul) << 8)				      \
 | |
|       | (((x) & 0x0000000000ff0000ul) << 24)				      \
 | |
|       | (((x) & 0x000000000000ff00ul) << 40)				      \
 | |
|       | (((x) & 0x00000000000000fful) << 56))
 | |
| 
 | |
| static __inline unsigned long int
 | |
| __bswap_64 (unsigned long int __bsx)
 | |
| {
 | |
|   return __bswap_constant_64 (__bsx);
 | |
| }
 | |
| #endif
 | |
| 
 | |
| #endif /* _BITS_BYTESWAP_H */
 |