Date: Wed, 8 Apr 2009 19:06:47 +0000 (UTC) From: Ed Schouten <ed@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r190853 - in head/sys: amd64/include i386/include Message-ID: <200904081906.n38J6ln1071504@svn.freebsd.org>
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Author: ed Date: Wed Apr 8 19:06:47 2009 New Revision: 190853 URL: http://svn.freebsd.org/changeset/base/190853 Log: Implement __bswap16() without using inline assembly. Most compilers nowadays (including GCC) are smart enough to know what's going on and generate more efficient code anyway. Submitted by: Christoph Mallon <christoph.mallon@gmx.de> Modified: head/sys/amd64/include/endian.h head/sys/i386/include/endian.h Modified: head/sys/amd64/include/endian.h ============================================================================== --- head/sys/amd64/include/endian.h Wed Apr 8 18:30:42 2009 (r190852) +++ head/sys/amd64/include/endian.h Wed Apr 8 19:06:47 2009 (r190853) @@ -135,26 +135,6 @@ __extension__ ({ register __uint64_t __X #endif /* __OPTIMIZE__ */ -#define __byte_swap_word_var(x) \ -__extension__ ({ register __uint16_t __X = (x); \ - __asm ("xchgb %h0, %b0" : "+Q" (__X)); \ - __X; }) - -#ifdef __OPTIMIZE__ - -#define __byte_swap_word_const(x) \ - ((((x) & 0xff00) >> 8) | \ - (((x) & 0x00ff) << 8)) - -#define __byte_swap_word(x) (__builtin_constant_p(x) ? \ - __byte_swap_word_const(x) : __byte_swap_word_var(x)) - -#else /* __OPTIMIZE__ */ - -#define __byte_swap_word(x) __byte_swap_word_var(x) - -#endif /* __OPTIMIZE__ */ - static __inline __uint64_t __bswap64(__uint64_t _x) { @@ -172,8 +152,7 @@ __bswap32(__uint32_t _x) static __inline __uint16_t __bswap16(__uint16_t _x) { - - return (__byte_swap_word(_x)); + return (_x << 8 | _x >> 8); } #define __htonl(x) __bswap32(x) Modified: head/sys/i386/include/endian.h ============================================================================== --- head/sys/i386/include/endian.h Wed Apr 8 18:30:42 2009 (r190852) +++ head/sys/i386/include/endian.h Wed Apr 8 19:06:47 2009 (r190853) @@ -109,26 +109,6 @@ __extension__ ({ register __uint32_t __X #endif /* __OPTIMIZE__ */ -#define __byte_swap_word_var(x) \ -__extension__ ({ register __uint16_t __X = (x); \ - __asm ("xchgb %h0, %b0" : "+q" (__X)); \ - __X; }) - -#ifdef __OPTIMIZE__ - -#define __byte_swap_word_const(x) \ - ((((x) & 0xff00) >> 8) | \ - (((x) & 0x00ff) << 8)) - -#define __byte_swap_word(x) (__builtin_constant_p(x) ? \ - __byte_swap_word_const(x) : __byte_swap_word_var(x)) - -#else /* __OPTIMIZE__ */ - -#define __byte_swap_word(x) __byte_swap_word_var(x) - -#endif /* __OPTIMIZE__ */ - static __inline __uint64_t __bswap64(__uint64_t _x) { @@ -149,8 +129,7 @@ __bswap32(__uint32_t _x) static __inline __uint16_t __bswap16(__uint16_t _x) { - - return (__byte_swap_word(_x)); + return (_x << 8 | _x >> 8); } #define __htonl(x) __bswap32(x)
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