xref: /llvm-project/offload/DeviceRTL/include/DeviceUtils.h (revision 74d5373f49fab0943a45a9214dc7a134f9f112f1)
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<T>, float> || is_same_v<remove_cv_t<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
101