xref: /llvm-project/offload/DeviceRTL/include/Mapping.h (revision 08533a3ee8f3a09a59cf6ac3be59198b26b7f739)
1 //===--------- Mapping.h - OpenMP device runtime mapping helpers -- 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_MAPPING_H
13 #define OMPTARGET_MAPPING_H
14 
15 #include "DeviceTypes.h"
16 
17 namespace ompx {
18 
19 namespace mapping {
20 
21 enum {
22   DIM_X = 0,
23   DIM_Y = 1,
24   DIM_Z = 2,
25 };
26 
27 #pragma omp begin declare target device_type(nohost)
28 
29 inline constexpr uint32_t MaxThreadsPerTeam = 1024;
30 
31 #pragma omp end declare target
32 
33 /// Initialize the mapping machinery.
34 void init(bool IsSPMD);
35 
36 /// Return true if the kernel is executed in SPMD mode.
37 bool isSPMDMode();
38 
39 /// Return true if the kernel is executed in generic mode.
40 bool isGenericMode();
41 
42 /// Return true if the executing thread is the main thread in generic mode.
43 /// These functions will lookup state and it is required that that is OK for the
44 /// thread and location. See also `isInitialThreadInLevel0` for a stateless
45 /// alternative for certain situations, e.g. during initialization.
46 bool isMainThreadInGenericMode();
47 bool isMainThreadInGenericMode(bool IsSPMD);
48 
49 /// Return true if this thread is the initial thread in parallel level 0.
50 ///
51 /// The thread for which this returns true should be used for single threaded
52 /// initialization tasks. We pick a special thread to ensure there are no
53 /// races between the initialization and the first read of initialized state.
54 bool isInitialThreadInLevel0(bool IsSPMD);
55 
56 /// Return true if the executing thread has the lowest Id of the active threads
57 /// in the warp.
58 bool isLeaderInWarp();
59 
60 /// Return a mask describing all active threads in the warp.
61 LaneMaskTy activemask();
62 
63 /// Return a mask describing all threads with a smaller Id in the warp.
64 LaneMaskTy lanemaskLT();
65 
66 /// Return a mask describing all threads with a larget Id in the warp.
67 LaneMaskTy lanemaskGT();
68 
69 /// Return the thread Id in the warp, in [0, getWarpSize()).
70 uint32_t getThreadIdInWarp();
71 
72 /// Return the warp size, thus number of threads in the warp.
73 uint32_t getWarpSize();
74 
75 /// Return the warp id in the block, in [0, getNumberOfWarpsInBlock()]
76 uint32_t getWarpIdInBlock();
77 
78 /// Return the number of warps in the block.
79 uint32_t getNumberOfWarpsInBlock();
80 
81 /// Return the thread Id in the block, in [0, getNumberOfThreadsInBlock(Dim)).
82 uint32_t getThreadIdInBlock(int32_t Dim = DIM_X);
83 
84 /// Return the block size, thus number of threads in the block.
85 uint32_t getNumberOfThreadsInBlock(int32_t Dim = DIM_X);
86 
87 /// Return the block Id in the kernel, in [0, getNumberOfBlocksInKernel(Dim)).
88 uint32_t getBlockIdInKernel(int32_t Dim = DIM_X);
89 
90 /// Return the number of blocks in the kernel.
91 uint32_t getNumberOfBlocksInKernel(int32_t Dim = DIM_X);
92 
93 /// Return the kernel size, thus number of threads in the kernel.
94 uint32_t getNumberOfThreadsInKernel();
95 
96 /// Return the maximal number of threads in the block usable for a team (=
97 /// parallel region).
98 ///
99 /// Note: The version taking \p IsSPMD mode explicitly can be used during the
100 /// initialization of the target region, that is before `mapping::isSPMDMode()`
101 /// can be called by any thread other than the main one.
102 uint32_t getMaxTeamThreads();
103 uint32_t getMaxTeamThreads(bool IsSPMD);
104 
105 /// Return the number of processing elements on the device.
106 uint32_t getNumberOfProcessorElements();
107 
108 } // namespace mapping
109 
110 } // namespace ompx
111 
112 #endif
113