hphp/util/arch.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16
  17 #ifndef incl_HPHP_ARCH_H
  18 #define incl_HPHP_ARCH_H
  19
  20 #include "hphp/util/assertions.h"
  21
  22 namespace HPHP {
  23 ///////////////////////////////////////////////////////////////////////////////
  24
  25 enum class Arch { X64, ARM, PPC64, };
  26
  27 constexpr Arch arch() {
  28 #if defined(__powerpc64__)
  29   return Arch::PPC64;
  30 #elif defined(__aarch64__)
  31   return Arch::ARM;
  32 #else
  33   return Arch::X64;
  34 #endif
  35 }
  36
  37 constexpr bool arch_any() { return false; }
  38
  39 /*
  40  * Convenience helper for guarding on a set of architectures.
  41  */
  42 template<class... Tail>
  43 bool arch_any(Arch a, Tail&&... archs) {
  44   return arch() == a || arch_any(archs...);
  45 }
  46
  47 /*
  48  * MSVC's Preprocessor is completely idiotic, so we have to play by its rules
  49  * and forcefully expand the variadic args so they aren't all interpreted as the
  50  * first argument to func.
  51  */
  52 #define MSVC_GLUE(x, y) x y
  53
  54 /*
  55  * Macro for defining easy arch-dispatch wrappers.
  56  *
  57  * We need to specify the return type explicitly, or else we may drop refs.
  58  */
  59 #define ARCH_SWITCH_CALL(func, ...)                                   \
  60   ([&]() -> decltype(x64::func(__VA_ARGS__)) {                        \
  61     switch (arch()) {                                                 \
  62       case Arch::X64:                                                 \
  63         return x64::MSVC_GLUE(func, (__VA_ARGS__));                   \
  64       case Arch::ARM:                                                 \
  65         return arm::MSVC_GLUE(func, (__VA_ARGS__));                   \
  66       case Arch::PPC64:                                               \
  67         return ppc64::MSVC_GLUE(func, (__VA_ARGS__));                 \
  68     }                                                                 \
  69     not_reached();                                                    \
  70   }())
  71
  72 ///////////////////////////////////////////////////////////////////////////////
  73
  74 }
  75
  76 #endif