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Diffstat (limited to 'boost/uuid/detail/uuid_x86.hpp')
| -rw-r--r-- | boost/uuid/detail/uuid_x86.hpp | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/boost/uuid/detail/uuid_x86.hpp b/boost/uuid/detail/uuid_x86.hpp deleted file mode 100644 index 120b8d60dc..0000000000 --- a/boost/uuid/detail/uuid_x86.hpp +++ /dev/null @@ -1,135 +0,0 @@ -/* - * Copyright Andrey Semashev 2013. - * Distributed under the Boost Software License, Version 1.0. - * (See accompanying file LICENSE_1_0.txt or copy at - * http://www.boost.org/LICENSE_1_0.txt) - */ -/*! - * \file uuid/detail/uuid_x86.hpp - * - * \brief This header contains optimized SSE implementation of \c boost::uuid operations. - */ - -#ifndef BOOST_UUID_DETAIL_UUID_X86_HPP_INCLUDED_ -#define BOOST_UUID_DETAIL_UUID_X86_HPP_INCLUDED_ - -// MSVC does not always have immintrin.h (at least, not up to MSVC 10), so include the appropriate header for each instruction set -#if defined(BOOST_UUID_USE_SSE41) -#include <smmintrin.h> -#elif defined(BOOST_UUID_USE_SSE3) -#include <pmmintrin.h> -#else -#include <emmintrin.h> -#endif - -#if defined(BOOST_MSVC) && defined(_M_X64) && !defined(BOOST_UUID_USE_SSE3) && (BOOST_MSVC < 1900 /* Fixed in Visual Studio 2015 */ ) -// At least MSVC 9 (VS2008) and 12 (VS2013) have an optimizer bug that sometimes results in incorrect SIMD code -// generated in Release x64 mode. In particular, it affects operator==, where the compiler sometimes generates -// pcmpeqd with a memory opereand instead of movdqu followed by pcmpeqd. The problem is that uuid can be -// not aligned to 16 bytes and pcmpeqd causes alignment violation in this case. We cannot be sure that other -// MSVC versions are not affected so we apply the workaround for all versions, except VS2015 on up where -// the bug has been fixed. -// -// https://svn.boost.org/trac/boost/ticket/8509#comment:3 -// https://connect.microsoft.com/VisualStudio/feedbackdetail/view/981648#tabs -#define BOOST_UUID_DETAIL_MSVC_BUG981648 -#if BOOST_MSVC >= 1600 -extern "C" void _ReadWriteBarrier(void); -#pragma intrinsic(_ReadWriteBarrier) -#endif -#endif - -namespace boost { -namespace uuids { -namespace detail { - -BOOST_FORCEINLINE __m128i load_unaligned_si128(const uint8_t* p) BOOST_NOEXCEPT -{ -#if defined(BOOST_UUID_USE_SSE3) - return _mm_lddqu_si128(reinterpret_cast< const __m128i* >(p)); -#elif !defined(BOOST_UUID_DETAIL_MSVC_BUG981648) - return _mm_loadu_si128(reinterpret_cast< const __m128i* >(p)); -#elif defined(BOOST_MSVC) && BOOST_MSVC >= 1600 - __m128i mm = _mm_loadu_si128(reinterpret_cast< const __m128i* >(p)); - // Make sure this load doesn't get merged with the subsequent instructions - _ReadWriteBarrier(); - return mm; -#else - // VS2008 x64 doesn't respect _ReadWriteBarrier above, so we have to generate this crippled code to load unaligned data - return _mm_unpacklo_epi64(_mm_loadl_epi64(reinterpret_cast< const __m128i* >(p)), _mm_loadl_epi64(reinterpret_cast< const __m128i* >(p + 8))); -#endif -} - -} // namespace detail - -inline bool uuid::is_nil() const BOOST_NOEXCEPT -{ - __m128i mm = uuids::detail::load_unaligned_si128(data); -#if defined(BOOST_UUID_USE_SSE41) - return _mm_test_all_zeros(mm, mm) != 0; -#else - mm = _mm_cmpeq_epi32(mm, _mm_setzero_si128()); - return _mm_movemask_epi8(mm) == 0xFFFF; -#endif -} - -inline void uuid::swap(uuid& rhs) BOOST_NOEXCEPT -{ - __m128i mm_this = uuids::detail::load_unaligned_si128(data); - __m128i mm_rhs = uuids::detail::load_unaligned_si128(rhs.data); - _mm_storeu_si128(reinterpret_cast< __m128i* >(rhs.data), mm_this); - _mm_storeu_si128(reinterpret_cast< __m128i* >(data), mm_rhs); -} - -inline bool operator== (uuid const& lhs, uuid const& rhs) BOOST_NOEXCEPT -{ - __m128i mm_left = uuids::detail::load_unaligned_si128(lhs.data); - __m128i mm_right = uuids::detail::load_unaligned_si128(rhs.data); - -#if defined(BOOST_UUID_USE_SSE41) - __m128i mm = _mm_xor_si128(mm_left, mm_right); - return _mm_test_all_zeros(mm, mm) != 0; -#else - __m128i mm_cmp = _mm_cmpeq_epi32(mm_left, mm_right); - return _mm_movemask_epi8(mm_cmp) == 0xFFFF; -#endif -} - -inline bool operator< (uuid const& lhs, uuid const& rhs) BOOST_NOEXCEPT -{ - __m128i mm_left = uuids::detail::load_unaligned_si128(lhs.data); - __m128i mm_right = uuids::detail::load_unaligned_si128(rhs.data); - - // To emulate lexicographical_compare behavior we have to perform two comparisons - the forward and reverse one. - // Then we know which bytes are equivalent and which ones are different, and for those different the comparison results - // will be opposite. Then we'll be able to find the first differing comparison result (for both forward and reverse ways), - // and depending on which way it is for, this will be the result of the operation. There are a few notes to consider: - // - // 1. Due to little endian byte order the first bytes go into the lower part of the xmm registers, - // so the comparison results in the least significant bits will actually be the most signigicant for the final operation result. - // This means we have to determine which of the comparison results have the least significant bit on, and this is achieved with - // the "(x - 1) ^ x" trick. - // 2. Because there is only signed comparison in SSE/AVX, we have to invert byte comparison results whenever signs of the corresponding - // bytes are different. I.e. in signed comparison it's -1 < 1, but in unsigned it is the opposite (255 > 1). To do that we XOR left and right, - // making the most significant bit of each byte 1 if the signs are different, and later apply this mask with another XOR to the comparison results. - // 3. pcmpgtw compares for "greater" relation, so we swap the arguments to get what we need. - - const __m128i mm_signs_mask = _mm_xor_si128(mm_left, mm_right); - - __m128i mm_cmp = _mm_cmpgt_epi8(mm_right, mm_left), mm_rcmp = _mm_cmpgt_epi8(mm_left, mm_right); - - mm_cmp = _mm_xor_si128(mm_signs_mask, mm_cmp); - mm_rcmp = _mm_xor_si128(mm_signs_mask, mm_rcmp); - - uint32_t cmp = static_cast< uint32_t >(_mm_movemask_epi8(mm_cmp)), rcmp = static_cast< uint32_t >(_mm_movemask_epi8(mm_rcmp)); - - cmp = (cmp - 1u) ^ cmp; - rcmp = (rcmp - 1u) ^ rcmp; - - return cmp < rcmp; -} - -} // namespace uuids -} // namespace boost - -#endif // BOOST_UUID_DETAIL_UUID_X86_HPP_INCLUDED_ |