xref: /netbsd-src/external/gpl3/gdb.old/dist/libctf/swap.h (revision 6881a4007f077b54e5f51159c52b9b25f57deb0d)
17d62b00eSchristos /* Interface to byteswapping functions.
2*6881a400Schristos    Copyright (C) 2006-2022 Free Software Foundation, Inc.
37d62b00eSchristos 
47d62b00eSchristos    This file is part of libctf.
57d62b00eSchristos 
67d62b00eSchristos    libctf is free software; you can redistribute it and/or modify it under
77d62b00eSchristos    the terms of the GNU General Public License as published by the Free
87d62b00eSchristos    Software Foundation; either version 3, or (at your option) any later
97d62b00eSchristos    version.
107d62b00eSchristos 
117d62b00eSchristos    This program is distributed in the hope that it will be useful, but
127d62b00eSchristos    WITHOUT ANY WARRANTY; without even the implied warranty of
137d62b00eSchristos    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
147d62b00eSchristos    See the GNU General Public License for more details.
157d62b00eSchristos 
167d62b00eSchristos    You should have received a copy of the GNU General Public License
177d62b00eSchristos    along with this program; see the file COPYING.  If not see
187d62b00eSchristos    <http://www.gnu.org/licenses/>.  */
197d62b00eSchristos 
207d62b00eSchristos #ifndef _CTF_SWAP_H
217d62b00eSchristos #define _CTF_SWAP_H
227d62b00eSchristos 
237d62b00eSchristos #include "config.h"
247d62b00eSchristos #include <stdint.h>
25*6881a400Schristos #include <assert.h>
267d62b00eSchristos 
277d62b00eSchristos #ifdef HAVE_BYTESWAP_H
287d62b00eSchristos #include <byteswap.h>
297d62b00eSchristos #endif /* defined(HAVE_BYTESWAP_H) */
307d62b00eSchristos 
317d62b00eSchristos /* Provide our own versions of the byteswap functions.  */
327d62b00eSchristos 
337d62b00eSchristos #if !HAVE_DECL_BSWAP_16
347d62b00eSchristos static inline uint16_t
357d62b00eSchristos bswap_16 (uint16_t v)
367d62b00eSchristos {
377d62b00eSchristos   return ((v >> 8) & 0xff) | ((v & 0xff) << 8);
387d62b00eSchristos }
397d62b00eSchristos #endif /* !HAVE_DECL_BSWAP16 */
407d62b00eSchristos 
417d62b00eSchristos #if !HAVE_DECL_BSWAP_32
427d62b00eSchristos static inline uint32_t
437d62b00eSchristos bswap_32 (uint32_t v)
447d62b00eSchristos {
457d62b00eSchristos   return (  ((v & 0xff000000) >> 24)
467d62b00eSchristos 	  | ((v & 0x00ff0000) >>  8)
477d62b00eSchristos 	  | ((v & 0x0000ff00) <<  8)
487d62b00eSchristos 	  | ((v & 0x000000ff) << 24));
497d62b00eSchristos }
507d62b00eSchristos #endif /* !HAVE_DECL_BSWAP32 */
517d62b00eSchristos 
527d62b00eSchristos #if !HAVE_DECL_BSWAP_64
537d62b00eSchristos static inline uint64_t
547d62b00eSchristos bswap_64 (uint64_t v)
557d62b00eSchristos {
567d62b00eSchristos   return (  ((v & 0xff00000000000000ULL) >> 56)
577d62b00eSchristos 	  | ((v & 0x00ff000000000000ULL) >> 40)
587d62b00eSchristos 	  | ((v & 0x0000ff0000000000ULL) >> 24)
597d62b00eSchristos 	  | ((v & 0x000000ff00000000ULL) >>  8)
607d62b00eSchristos 	  | ((v & 0x00000000ff000000ULL) <<  8)
617d62b00eSchristos 	  | ((v & 0x0000000000ff0000ULL) << 24)
627d62b00eSchristos 	  | ((v & 0x000000000000ff00ULL) << 40)
637d62b00eSchristos 	  | ((v & 0x00000000000000ffULL) << 56));
647d62b00eSchristos }
657d62b00eSchristos #endif /* !HAVE_DECL_BSWAP64 */
667d62b00eSchristos 
67*6881a400Schristos /* < C11? define away static assertions.  */
68*6881a400Schristos 
69*6881a400Schristos #if !defined (__STDC_VERSION__) || __STDC_VERSION__ < 201112L
70*6881a400Schristos #define _Static_assert(cond, err)
71*6881a400Schristos #endif
72*6881a400Schristos 
73*6881a400Schristos /* Swap the endianness of something.  */
74*6881a400Schristos 
75*6881a400Schristos #define swap_thing(x)							\
76*6881a400Schristos   do									\
77*6881a400Schristos     {									\
78*6881a400Schristos       _Static_assert (sizeof (x) == 1 || (sizeof (x) % 2 == 0		\
79*6881a400Schristos 					  && sizeof (x) <= 8),		\
80*6881a400Schristos 		      "Invalid size, update endianness code");		\
81*6881a400Schristos       switch (sizeof (x)) {						\
82*6881a400Schristos       case 2: x = bswap_16 (x); break;					\
83*6881a400Schristos       case 4: x = bswap_32 (x); break;					\
84*6881a400Schristos       case 8: x = bswap_64 (x); break;					\
85*6881a400Schristos       case 1: /* Nothing needs doing */					\
86*6881a400Schristos 	break;								\
87*6881a400Schristos       }									\
88*6881a400Schristos     }									\
89*6881a400Schristos   while (0);
90*6881a400Schristos 
91*6881a400Schristos 
927d62b00eSchristos #endif /* !defined(_CTF_SWAP_H) */
93