xref: /netbsd-src/external/gpl3/gdb/dist/libctf/swap.h (revision 12989c96ee862c63521a9ead8c44629b7a2ba9b1)
18dffb485Schristos /* Interface to byteswapping functions.
2*12989c96Schristos    Copyright (C) 2006-2024 Free Software Foundation, Inc.
38dffb485Schristos 
48dffb485Schristos    This file is part of libctf.
58dffb485Schristos 
68dffb485Schristos    libctf is free software; you can redistribute it and/or modify it under
78dffb485Schristos    the terms of the GNU General Public License as published by the Free
88dffb485Schristos    Software Foundation; either version 3, or (at your option) any later
98dffb485Schristos    version.
108dffb485Schristos 
118dffb485Schristos    This program is distributed in the hope that it will be useful, but
128dffb485Schristos    WITHOUT ANY WARRANTY; without even the implied warranty of
138dffb485Schristos    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
148dffb485Schristos    See the GNU General Public License for more details.
158dffb485Schristos 
168dffb485Schristos    You should have received a copy of the GNU General Public License
178dffb485Schristos    along with this program; see the file COPYING.  If not see
188dffb485Schristos    <http://www.gnu.org/licenses/>.  */
198dffb485Schristos 
208dffb485Schristos #ifndef _CTF_SWAP_H
218dffb485Schristos #define _CTF_SWAP_H
228dffb485Schristos 
238dffb485Schristos #include "config.h"
248dffb485Schristos #include <stdint.h>
254b169a6bSchristos #include <assert.h>
268dffb485Schristos 
278dffb485Schristos #ifdef HAVE_BYTESWAP_H
288dffb485Schristos #include <byteswap.h>
298dffb485Schristos #endif /* defined(HAVE_BYTESWAP_H) */
308dffb485Schristos 
318dffb485Schristos /* Provide our own versions of the byteswap functions.  */
328dffb485Schristos 
338dffb485Schristos #if !HAVE_DECL_BSWAP_16
348dffb485Schristos static inline uint16_t
358dffb485Schristos bswap_16 (uint16_t v)
368dffb485Schristos {
378dffb485Schristos   return ((v >> 8) & 0xff) | ((v & 0xff) << 8);
388dffb485Schristos }
398dffb485Schristos #endif /* !HAVE_DECL_BSWAP16 */
408dffb485Schristos 
418dffb485Schristos #if !HAVE_DECL_BSWAP_32
428dffb485Schristos static inline uint32_t
438dffb485Schristos bswap_32 (uint32_t v)
448dffb485Schristos {
458dffb485Schristos   return (  ((v & 0xff000000) >> 24)
468dffb485Schristos 	  | ((v & 0x00ff0000) >>  8)
478dffb485Schristos 	  | ((v & 0x0000ff00) <<  8)
488dffb485Schristos 	  | ((v & 0x000000ff) << 24));
498dffb485Schristos }
508dffb485Schristos #endif /* !HAVE_DECL_BSWAP32 */
518dffb485Schristos 
528dffb485Schristos #if !HAVE_DECL_BSWAP_64
538dffb485Schristos static inline uint64_t
548dffb485Schristos bswap_64 (uint64_t v)
558dffb485Schristos {
568dffb485Schristos   return (  ((v & 0xff00000000000000ULL) >> 56)
578dffb485Schristos 	  | ((v & 0x00ff000000000000ULL) >> 40)
588dffb485Schristos 	  | ((v & 0x0000ff0000000000ULL) >> 24)
598dffb485Schristos 	  | ((v & 0x000000ff00000000ULL) >>  8)
608dffb485Schristos 	  | ((v & 0x00000000ff000000ULL) <<  8)
618dffb485Schristos 	  | ((v & 0x0000000000ff0000ULL) << 24)
628dffb485Schristos 	  | ((v & 0x000000000000ff00ULL) << 40)
638dffb485Schristos 	  | ((v & 0x00000000000000ffULL) << 56));
648dffb485Schristos }
658dffb485Schristos #endif /* !HAVE_DECL_BSWAP64 */
668dffb485Schristos 
674b169a6bSchristos /* < C11? define away static assertions.  */
684b169a6bSchristos 
694b169a6bSchristos #if !defined (__STDC_VERSION__) || __STDC_VERSION__ < 201112L
70*12989c96Schristos #ifndef _Static_assert
714b169a6bSchristos #define _Static_assert(cond, err)
724b169a6bSchristos #endif
73*12989c96Schristos #endif
744b169a6bSchristos 
754b169a6bSchristos /* Swap the endianness of something.  */
764b169a6bSchristos 
774b169a6bSchristos #define swap_thing(x)							\
784b169a6bSchristos   do									\
794b169a6bSchristos     {									\
804b169a6bSchristos       _Static_assert (sizeof (x) == 1 || (sizeof (x) % 2 == 0		\
814b169a6bSchristos 					  && sizeof (x) <= 8),		\
824b169a6bSchristos 		      "Invalid size, update endianness code");		\
834b169a6bSchristos       switch (sizeof (x)) {						\
844b169a6bSchristos       case 2: x = bswap_16 (x); break;					\
854b169a6bSchristos       case 4: x = bswap_32 (x); break;					\
864b169a6bSchristos       case 8: x = bswap_64 (x); break;					\
874b169a6bSchristos       case 1: /* Nothing needs doing */					\
884b169a6bSchristos 	break;								\
894b169a6bSchristos       }									\
904b169a6bSchristos     }									\
914b169a6bSchristos   while (0);
924b169a6bSchristos 
934b169a6bSchristos 
948dffb485Schristos #endif /* !defined(_CTF_SWAP_H) */
95