From: "Anthony G. Basile" blueness@gentoo.org

On systems where uClibc doesn't provide an arch specific byteswap.h, we fall back on bits/byteswap-common.h. However, there is a bug in this header in the __bswap_constant_64(x) macro. If, for example, a double is passed, we get 'invalid operands to binary &' in which we mismatch a 'double' and 'long long unsigned int'. The newer glibc headers fix this and so we import them. Also, since the inclusion of byteswap.h is not appropriate for assembly code, we guard a portion of endian.h which uses byteswap.h from inclusion in any assembly.

This is needed, for example, for f2fs-tools 1.6.0 on 32-bit big endian PowerPC.

Signed-off-by: Anthony G. Basile blueness@gentoo.org --- include/endian.h | 2 +- libc/sysdeps/linux/common/bits/byteswap-16.h | 34 +++++++ libc/sysdeps/linux/common/bits/byteswap-common.h | 109 ++++++++++++----------- 3 files changed, 92 insertions(+), 53 deletions(-) create mode 100644 libc/sysdeps/linux/common/bits/byteswap-16.h

diff --git a/include/endian.h b/include/endian.h index 23a2654..eb2039e 100644 --- a/include/endian.h +++ b/include/endian.h @@ -66,7 +66,7 @@ # endif #endif

-#ifdef __USE_BSD +#if defined(__USE_BSD) && !defined(__ASSEMBLER__) /* Conversion interfaces. */ # include <byteswap.h>

diff --git a/libc/sysdeps/linux/common/bits/byteswap-16.h b/libc/sysdeps/linux/common/bits/byteswap-16.h new file mode 100644 index 0000000..8063aa8 --- /dev/null +++ b/libc/sysdeps/linux/common/bits/byteswap-16.h @@ -0,0 +1,34 @@ +/* Macros to swap the order of bytes in 16-bit integer values. + Copyright (C) 2012-2016 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/. */ + +#ifndef _BITS_BYTESWAP_H +# error "Never use <bits/byteswap-16.h> directly; include <byteswap.h> instead." +#endif + +#ifdef __GNUC__ +# define __bswap_16(x) \ + (__extension__ \ + ({ unsigned short int __bsx = (unsigned short int) (x); \ + __bswap_constant_16 (__bsx); })) +#else +static __inline unsigned short int +__bswap_16 (unsigned short int __bsx) +{ + return __bswap_constant_16 (__bsx); +} +#endif diff --git a/libc/sysdeps/linux/common/bits/byteswap-common.h b/libc/sysdeps/linux/common/bits/byteswap-common.h index 4941d47..0effea6 100644 --- a/libc/sysdeps/linux/common/bits/byteswap-common.h +++ b/libc/sysdeps/linux/common/bits/byteswap-common.h @@ -1,5 +1,5 @@ /* Macros to swap the order of bytes in integer values. - Copyright (C) 1997,1998,2000,2001,2002,2005 Free Software Foundation, Inc. + Copyright (C) 1997-2016 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 @@ -16,54 +16,40 @@ License along with the GNU C Library; if not, see http://www.gnu.org/licenses/. */

-#if !defined _BYTESWAP_H && !defined _NETINET_IN_H +#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

+#include <features.h> +#include <bits/types.h> + /* Swap bytes in 16 bit value. */ #define __bswap_constant_16(x) \ - ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)) + ((unsigned short int)((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)))

-#ifndef __bswap_non_constant_16 -# define __bswap_non_constant_16(x) __bswap_constant_16(x) -#endif -#ifdef __GNUC__ -# define __bswap_16(x) \ - (__extension__ \ - ({ unsigned short int __bsv, __bsx = (x); \ - if (__builtin_constant_p (__bsx)) \ - __bsv = __bswap_constant_16 (__bsx); \ - else \ - __bsv = __bswap_non_constant_16 (__bsx); \ - __bsv; })) -#else -static __inline unsigned short int -__bswap_16 (unsigned short int __bsx) -{ - return __bswap_constant_16 (__bsx); -} -#endif +/* Get __bswap_16. */ +#include <bits/byteswap-16.h>

/* Swap bytes in 32 bit value. */ #define __bswap_constant_32(x) \ ((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >> 8) | \ (((x) & 0x0000ff00u) << 8) | (((x) & 0x000000ffu) << 24))

-#ifndef __bswap_non_constant_32 -# define __bswap_non_constant_32(x) __bswap_constant_32(x) -#endif #ifdef __GNUC__ -# define __bswap_32(x) \ - (__extension__ \ - ({ unsigned int __bsv, __bsx = (x); \ - if (__builtin_constant_p (__bsx)) \ - __bsv = __bswap_constant_32 (__bsx); \ - else \ - __bsv = __bswap_non_constant_32 (__bsx); \ - __bsv; })) +# if __GNUC_PREREQ (4, 3) +static __inline unsigned int +__bswap_32 (unsigned int __bsx) +{ + return __builtin_bswap32 (__bsx); +} +# else +# define __bswap_32(x) \ + (__extension__ \ + ({ unsigned int __bsx = (x); __bswap_constant_32 (__bsx); })) +# endif #else static __inline unsigned int __bswap_32 (unsigned int __bsx) @@ -72,8 +58,40 @@ __bswap_32 (unsigned int __bsx) } #endif

-#if defined __GNUC__ && __GNUC__ >= 2 /* Swap bytes in 64 bit value. */ +#if __GNUC_PREREQ (2, 0) +# define __bswap_constant_64(x) \ + (__extension__ ((((x) & 0xff00000000000000ull) >> 56) \ + | (((x) & 0x00ff000000000000ull) >> 40) \ + | (((x) & 0x0000ff0000000000ull) >> 24) \ + | (((x) & 0x000000ff00000000ull) >> 8) \ + | (((x) & 0x00000000ff000000ull) << 8) \ + | (((x) & 0x0000000000ff0000ull) << 24) \ + | (((x) & 0x000000000000ff00ull) << 40) \ + | (((x) & 0x00000000000000ffull) << 56))) + +# if __GNUC_PREREQ (4, 3) +static __inline __uint64_t +__bswap_64 (__uint64_t __bsx) +{ + return __builtin_bswap64 (__bsx); +} +# else +# define __bswap_64(x) \ + (__extension__ \ + ({ union { __extension__ __uint64_t __ll; \ + unsigned int __l[2]; } __w, __r; \ + if (__builtin_constant_p (x)) \ + __r.__ll = __bswap_constant_64 (x); \ + else \ + { \ + __w.__ll = (x); \ + __r.__l[0] = __bswap_32 (__w.__l[1]); \ + __r.__l[1] = __bswap_32 (__w.__l[0]); \ + } \ + __r.__ll; })) +# endif +#else # define __bswap_constant_64(x) \ ((((x) & 0xff00000000000000ull) >> 56) \ | (((x) & 0x00ff000000000000ull) >> 40) \ @@ -84,24 +102,11 @@ __bswap_32 (unsigned int __bsx) | (((x) & 0x000000000000ff00ull) << 40) \ | (((x) & 0x00000000000000ffull) << 56))

-# ifndef __bswap_non_constant_64 -# define __bswap_non_constant_64(x) \ - (__extension__ \ - ({ union { __extension__ unsigned long long int __ll; \ - unsigned int __l[2]; } __w, __r; \ - __w.__ll = (x); \ - __r.__l[0] = __bswap_non_constant_32 (__w.__l[1]); \ - __r.__l[1] = __bswap_non_constant_32 (__w.__l[0]); \ - __r.__ll; })) -# endif -# define __bswap_64(x) \ - (__extension__ \ - ({ __extension__ unsigned long long int __ll; \ - if (__builtin_constant_p (x)) \ - __ll = __bswap_constant_64 (x); \ - else \ - __ll = __bswap_non_constant_64 (x); \ - __ll; })) +static __inline __uint64_t +__bswap_64 (__uint64_t __bsx) +{ + return __bswap_constant_64 (__bsx); +} #endif

#endif /* _BITS_BYTESWAP_H */