From 33f725723f525357861abb4b3be8de250b6a7393 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 10 May 2005 19:54:38 +0000 Subject: [PATCH] optimization Originally committed as revision 4212 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/bswap.h | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/libavcodec/bswap.h b/libavcodec/bswap.h index a55dc4664f..2e55337f9a 100644 --- a/libavcodec/bswap.h +++ b/libavcodec/bswap.h @@ -19,7 +19,7 @@ #if defined(ARCH_X86) || defined(ARCH_X86_64) static always_inline uint16_t bswap_16(uint16_t x) { - __asm("xchgb %b0,%h0" : + __asm("rorw $8, %0" : LEGACY_REGS (x) : "0" (x)); return x; @@ -48,12 +48,15 @@ static inline uint64_t bswap_64(uint64_t x) "0" (x)); return x; #else - register union { __extension__ uint64_t __ll; - uint32_t __l[2]; } __x; - asm("xchgl %0,%1": - "=r"(__x.__l[0]),"=r"(__x.__l[1]): - "0"(bswap_32((uint32_t)x)),"1"(bswap_32((uint32_t)(x>>32)))); - return __x.__ll; + union { + uint64_t ll; + struct { + uint32_t l,h; + } l; + } r; + r.l.l = bswap_32 (x); + r.l.h = bswap_32 (x>>32); + return r.ll; #endif } @@ -92,11 +95,17 @@ static always_inline uint16_t bswap_16(uint16_t x){ } static always_inline uint32_t bswap_32(uint32_t x){ - return (x >> 24) | ((x & 0x00ff0000) >> 8) | ((x & 0x0000ff00) << 8) | (x << 24); + x= ((x<<8)&0xFF00FF00) | ((x>>8)&0x00FF00FF); + return (x>>16) | (x<<16); } static inline uint64_t bswap_64(uint64_t x) { +#if 0 + x= ((x<< 8)&0xFF00FF00FF00FF00ULL) | ((x>> 8)&0x00FF00FF00FF00FFULL); + x= ((x<<16)&0xFFFF0000FFFF0000ULL) | ((x>>16)&0x0000FFFF0000FFFFULL); + return (x>>32) | (x<<32); +#else union { uint64_t ll; uint32_t l[2]; @@ -105,6 +114,7 @@ static inline uint64_t bswap_64(uint64_t x) r.l[0] = bswap_32 (w.l[1]); r.l[1] = bswap_32 (w.l[0]); return r.ll; +#endif } #endif /* !ARCH_X86 */