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endian_inl.h: add BSwap64

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Change-Id: I66672b770500294b8f4ee8fa4bf1dfff1119dbe6
This commit is contained in:
James Zern 2014-07-03 11:21:24 -07:00
parent 47779d46c8
commit ee70a90187
2 changed files with 18 additions and 15 deletions
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16
src/utils/bit_reader_inl.h
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@ -72,21 +72,7 @@ static WEBP_INLINE void VP8LoadNewBytes(VP8BitReader* const br) {
br->buf_ += BITS >> 3;
#if !defined(__BIG_ENDIAN__)
#if (BITS > 32)
#if defined(HAVE_BUILTIN_BSWAP)
bits = (bit_t)__builtin_bswap64(in_bits);
#elif defined(_MSC_VER)
bits = (bit_t)_byteswap_uint64(in_bits);
#elif defined(__x86_64__)
__asm__ volatile("bswapq %0" : "=r"(bits) : "0"(in_bits));
#else // generic code for swapping 64-bit values (suggested by bdb@)
bits = (bit_t)in_bits;
bits = ((bits & 0xffffffff00000000ull) >> 32) |
((bits & 0x00000000ffffffffull) << 32);
bits = ((bits & 0xffff0000ffff0000ull) >> 16) |
((bits & 0x0000ffff0000ffffull) << 16);
bits = ((bits & 0xff00ff00ff00ff00ull) >> 8) |
((bits & 0x00ff00ff00ff00ffull) << 8);
#endif
bits = BSwap64(in_bits);
bits >>= 64 - BITS;
#elif (BITS >= 24)
bits = BSwap32(in_bits);

17
src/utils/endian_inl.h
View File

@ -70,4 +70,21 @@ static WEBP_INLINE uint32_t BSwap32(uint32_t x) {
#endif // HAVE_BUILTIN_BSWAP
}
static WEBP_INLINE uint64_t BSwap64(uint64_t x) {
#if defined(HAVE_BUILTIN_BSWAP)
return __builtin_bswap64(x);
#elif defined(__x86_64__)
uint64_t swapped_bytes;
__asm__ volatile("bswapq %0" : "=r"(swapped_bytes) : "0"(x));
return swapped_bytes;
#elif defined(_MSC_VER)
return (uint64_t)_byteswap_uint64(x);
#else // generic code for swapping 64-bit values (suggested by bdb@)
x = ((x & 0xffffffff00000000ull) >> 32) | ((x & 0x00000000ffffffffull) << 32);
x = ((x & 0xffff0000ffff0000ull) >> 16) | ((x & 0x0000ffff0000ffffull) << 16);
x = ((x & 0xff00ff00ff00ff00ull) >> 8) | ((x & 0x00ff00ff00ff00ffull) << 8);
return x;
#endif // HAVE_BUILTIN_BSWAP
}
#endif // WEBP_UTILS_ENDIAN_INL_H_