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author | ed <ed@FreeBSD.org> | 2009-04-08 19:06:47 +0000 |
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committer | ed <ed@FreeBSD.org> | 2009-04-08 19:06:47 +0000 |
commit | 9141c649b8dd9a1be83d66da54cb8f2f34f7a9be (patch) | |
tree | 1595a4719281107660c01afb844de3b02c3d9bba | |
parent | c781ca9c84dbc014af3281962e1b5ac3f8970ef3 (diff) | |
download | FreeBSD-src-9141c649b8dd9a1be83d66da54cb8f2f34f7a9be.zip FreeBSD-src-9141c649b8dd9a1be83d66da54cb8f2f34f7a9be.tar.gz |
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>
-rw-r--r-- | sys/amd64/include/endian.h | 23 | ||||
-rw-r--r-- | sys/i386/include/endian.h | 23 |
2 files changed, 2 insertions, 44 deletions
diff --git a/sys/amd64/include/endian.h b/sys/amd64/include/endian.h index 24e59e4..60e4b97 100644 --- a/sys/amd64/include/endian.h +++ b/sys/amd64/include/endian.h @@ -135,26 +135,6 @@ __extension__ ({ register __uint64_t __X = (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) diff --git a/sys/i386/include/endian.h b/sys/i386/include/endian.h index 59fa4a5..98fceb6 100644 --- a/sys/i386/include/endian.h +++ b/sys/i386/include/endian.h @@ -109,26 +109,6 @@ __extension__ ({ register __uint32_t __X = (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) |