diff options
Diffstat (limited to 'contrib/src/boost/uuid/detail/uuid_x86.hpp')
| -rw-r--r-- | contrib/src/boost/uuid/detail/uuid_x86.hpp | 270 |
1 files changed, 135 insertions, 135 deletions
diff --git a/contrib/src/boost/uuid/detail/uuid_x86.hpp b/contrib/src/boost/uuid/detail/uuid_x86.hpp index 2df17d3..5c73670 100644 --- a/contrib/src/boost/uuid/detail/uuid_x86.hpp +++ b/contrib/src/boost/uuid/detail/uuid_x86.hpp @@ -1,135 +1,135 @@ -/*
- * 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_
+/* + * 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 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_epi8(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); + + __m128i mm_cmp = _mm_cmpeq_epi32(mm_left, mm_right); + +#if defined(BOOST_UUID_USE_SSE41) + return _mm_test_all_ones(mm_cmp) != 0; +#else + 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_ |