offload/DeviceRTL/include/DeviceUtils.h

   1 //===--- DeviceUtils.h - OpenMP device runtime utility functions -- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 //
  10 //===----------------------------------------------------------------------===//
  11
  12 #ifndef OMPTARGET_DEVICERTL_DEVICE_UTILS_H
  13 #define OMPTARGET_DEVICERTL_DEVICE_UTILS_H
  14
  15 #include "DeviceTypes.h"
  16 #include "Shared/Utils.h"
  17
  18 #pragma omp begin declare target device_type(nohost)
  19
  20 namespace utils {
  21
  22 template <typename T> struct type_identity {
  23   using type = T;
  24 };
  25
  26 template <typename T, T v> struct integral_constant {
  27   inline static constexpr T value = v;
  28 };
  29
  30 /// Freestanding SFINAE helpers.
  31 template <class T> struct remove_cv : type_identity<T> {};
  32 template <class T> struct remove_cv<const T> : type_identity<T> {};
  33 template <class T> struct remove_cv<volatile T> : type_identity<T> {};
  34 template <class T> struct remove_cv<const volatile T> : type_identity<T> {};
  35 template <class T> using remove_cv_t = typename remove_cv<T>::type;
  36
  37 using true_type = integral_constant<bool, true>;
  38 using false_type = integral_constant<bool, false>;
  39
  40 template <typename T, typename U> struct is_same : false_type {};
  41 template <typename T> struct is_same<T, T> : true_type {};
  42 template <typename T, typename U>
  43 inline constexpr bool is_same_v = is_same<T, U>::value;
  44
  45 template <typename T> struct is_floating_point {
  46   inline static constexpr bool value =
  47       is_same_v<remove_cv<T>, float> || is_same_v<remove_cv<T>, double>;
  48 };
  49 template <typename T>
  50 inline constexpr bool is_floating_point_v = is_floating_point<T>::value;
  51
  52 template <bool B, typename T = void> struct enable_if;
  53 template <typename T> struct enable_if<true, T> : type_identity<T> {};
  54 template <bool B, typename T = void>
  55 using enable_if_t = typename enable_if<B, T>::type;
  56
  57 template <class T> struct remove_addrspace : type_identity<T> {};
  58 template <class T, int N>
  59 struct remove_addrspace<T [[clang::address_space(N)]]> : type_identity<T> {};
  60 template <class T>
  61 using remove_addrspace_t = typename remove_addrspace<T>::type;
  62
  63 template <typename To, typename From> inline To bitCast(From V) {
  64   static_assert(sizeof(To) == sizeof(From), "Bad conversion");
  65   return __builtin_bit_cast(To, V);
  66 }
  67
  68 /// Return the value \p Var from thread Id \p SrcLane in the warp if the thread
  69 /// is identified by \p Mask.
  70 int32_t shuffle(uint64_t Mask, int32_t Var, int32_t SrcLane, int32_t Width);
  71
  72 int32_t shuffleDown(uint64_t Mask, int32_t Var, uint32_t Delta, int32_t Width);
  73
  74 int64_t shuffleDown(uint64_t Mask, int64_t Var, uint32_t Delta, int32_t Width);
  75
  76 uint64_t ballotSync(uint64_t Mask, int32_t Pred);
  77
  78 /// Return \p LowBits and \p HighBits packed into a single 64 bit value.
  79 uint64_t pack(uint32_t LowBits, uint32_t HighBits);
  80
  81 /// Unpack \p Val into \p LowBits and \p HighBits.
  82 void unpack(uint64_t Val, uint32_t &LowBits, uint32_t &HighBits);
  83
  84 /// Return true iff \p Ptr is pointing into shared (local) memory (AS(3)).
  85 bool isSharedMemPtr(void *Ptr);
  86
  87 /// Return true iff \p Ptr is pointing into (thread) local memory (AS(5)).
  88 bool isThreadLocalMemPtr(void *Ptr);
  89
  90 /// A  pointer variable that has by design an `undef` value. Use with care.
  91 [[clang::loader_uninitialized]] static void *const UndefPtr;
  92
  93 #define OMP_LIKELY(EXPR) __builtin_expect((bool)(EXPR), true)
  94 #define OMP_UNLIKELY(EXPR) __builtin_expect((bool)(EXPR), false)
  95
  96 } // namespace utils
  97
  98 #pragma omp end declare target
  99
 100 #endif