ceph/src/boost/boost/atomic/detail/hwcaps_gcc_arm.hpp

   1 /*
   2  * Distributed under the Boost Software License, Version 1.0.
   3  * (See accompanying file LICENSE_1_0.txt or copy at
   4  * http://www.boost.org/LICENSE_1_0.txt)
   5  *
   6  * Copyright (c) 2017 Andrey Semashev
   7  */
   8 /*!
   9  * \file   atomic/detail/hwcaps_gcc_arm.hpp
  10  *
  11  * This header defines hardware capabilities macros for ARM
  12  */
  13
  14 #ifndef BOOST_ATOMIC_DETAIL_HWCAPS_GCC_ARM_HPP_INCLUDED_
  15 #define BOOST_ATOMIC_DETAIL_HWCAPS_GCC_ARM_HPP_INCLUDED_
  16
  17 #include <boost/atomic/detail/config.hpp>
  18 #include <boost/atomic/detail/platform.hpp>
  19
  20 #ifdef BOOST_HAS_PRAGMA_ONCE
  21 #pragma once
  22 #endif
  23
  24 #if defined(__GNUC__) && defined(__arm__) && (BOOST_ATOMIC_DETAIL_ARM_ARCH+0) >= 6
  25
  26 #if BOOST_ATOMIC_DETAIL_ARM_ARCH > 6
  27 // ARMv7 and later have dmb instruction
  28 #define BOOST_ATOMIC_DETAIL_ARM_HAS_DMB 1
  29 #endif
  30
  31 #if defined(__ARM_FEATURE_LDREX)
  32
  33 #if (__ARM_FEATURE_LDREX & 1)
  34 #define BOOST_ATOMIC_DETAIL_ARM_HAS_LDREXB_STREXB 1
  35 #endif
  36 #if (__ARM_FEATURE_LDREX & 2)
  37 #define BOOST_ATOMIC_DETAIL_ARM_HAS_LDREXH_STREXH 1
  38 #endif
  39 #if (__ARM_FEATURE_LDREX & 8)
  40 #define BOOST_ATOMIC_DETAIL_ARM_HAS_LDREXD_STREXD 1
  41 #endif
  42
  43 #else // defined(__ARM_FEATURE_LDREX)
  44
  45 #if !(defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6Z__))
  46
  47 // ARMv6k and ARMv7 have 8 and 16-bit ldrex/strex variants, but at least GCC 4.7 fails to compile them. GCC 4.9 is known to work.
  48 #if (__GNUC__ * 100 + __GNUC_MINOR__) >= 409
  49 #define BOOST_ATOMIC_DETAIL_ARM_HAS_LDREXB_STREXB 1
  50 #define BOOST_ATOMIC_DETAIL_ARM_HAS_LDREXH_STREXH 1
  51 #endif
  52
  53 #if !(((defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6ZK__)) && defined(__thumb__)) || defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7M__))
  54 // ARMv6k and ARMv7 except ARMv7-M have 64-bit ldrex/strex variants.
  55 // Unfortunately, GCC (at least 4.7.3 on Ubuntu) does not allocate register pairs properly when targeting ARMv6k Thumb,
  56 // which is required for ldrexd/strexd instructions, so we disable 64-bit support. When targeting ARMv6k ARM
  57 // or ARMv7 (both ARM and Thumb 2) it works as expected.
  58 #define BOOST_ATOMIC_DETAIL_ARM_HAS_LDREXD_STREXD 1
  59 #endif
  60
  61 #endif // !(defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6Z__))
  62
  63 #endif // defined(__ARM_FEATURE_LDREX)
  64
  65 #endif // defined(__GNUC__) && defined(__arm__) && (BOOST_ATOMIC_DETAIL_ARM_ARCH+0) >= 6
  66
  67 #endif // BOOST_ATOMIC_DETAIL_HWCAPS_GCC_ARM_HPP_INCLUDED_