1//===-------- Tasking.cpp - NVPTX OpenMP tasks support ------------ 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// Task implementation support.
10//
11// TODO: We should not allocate and execute the task in two steps. A new API is
12// needed for that though.
13//
14//===----------------------------------------------------------------------===//
15
16#include "DeviceTypes.h"
17#include "DeviceUtils.h"
18#include "Interface.h"
19#include "State.h"
20
21using namespace ompx;
22
23extern "C" {
24
25TaskDescriptorTy *__kmpc_omp_task_alloc(IdentTy *, int32_t, int32_t,
26 size_t TaskSizeInclPrivateValues,
27 size_t SharedValuesSize,
28 TaskFnTy TaskFn) {
29 auto TaskSizeInclPrivateValuesPadded =
30 utils::roundUp(TaskSizeInclPrivateValues, sizeof(void *));
31 auto TaskSizeTotal = TaskSizeInclPrivateValuesPadded + SharedValuesSize;
32 TaskDescriptorTy *TaskDescriptor = (TaskDescriptorTy *)memory::allocGlobal(
33 TaskSizeTotal, "explicit task descriptor");
34 TaskDescriptor->Payload =
35 utils::advancePtr(TaskDescriptor, TaskSizeInclPrivateValuesPadded);
36 TaskDescriptor->TaskFn = TaskFn;
37
38 return TaskDescriptor;
39}
40
41int32_t __kmpc_omp_task(IdentTy *Loc, uint32_t TId,
42 TaskDescriptorTy *TaskDescriptor) {
43 return __kmpc_omp_task_with_deps(Loc, TId, TaskDescriptor, 0, 0, 0, 0);
44}
45
46int32_t __kmpc_omp_task_with_deps(IdentTy *Loc, uint32_t TId,
47 TaskDescriptorTy *TaskDescriptor, int32_t,
48 void *, int32_t, void *) {
49 state::DateEnvironmentRAII DERAII(Loc);
50
51 TaskDescriptor->TaskFn(0, TaskDescriptor);
52
53 memory::freeGlobal(TaskDescriptor, "explicit task descriptor");
54 return 0;
55}
56
57void __kmpc_omp_task_begin_if0(IdentTy *Loc, uint32_t TId,
58 TaskDescriptorTy *TaskDescriptor) {
59 state::enterDataEnvironment(Loc);
60}
61
62void __kmpc_omp_task_complete_if0(IdentTy *Loc, uint32_t TId,
63 TaskDescriptorTy *TaskDescriptor) {
64 state::exitDataEnvironment();
65
66 memory::freeGlobal(TaskDescriptor, "explicit task descriptor");
67}
68
69void __kmpc_omp_wait_deps(IdentTy *Loc, uint32_t TId, int32_t, void *, int32_t,
70 void *) {}
71
72void __kmpc_taskgroup(IdentTy *Loc, uint32_t TId) {}
73
74void __kmpc_end_taskgroup(IdentTy *Loc, uint32_t TId) {}
75
76int32_t __kmpc_omp_taskyield(IdentTy *Loc, uint32_t TId, int) { return 0; }
77
78int32_t __kmpc_omp_taskwait(IdentTy *Loc, uint32_t TId) { return 0; }
79
80void __kmpc_taskloop(IdentTy *Loc, uint32_t TId,
81 TaskDescriptorTy *TaskDescriptor, int,
82 uint64_t *LowerBound, uint64_t *UpperBound, int64_t, int,
83 int32_t, uint64_t, void *) {
84 // Skip task entirely if empty iteration space.
85 if (*LowerBound > *UpperBound)
86 return;
87
88 // The compiler has already stored lb and ub in the TaskDescriptorTy structure
89 // as we are using a single task to execute the entire loop, we can leave
90 // the initial task_t untouched
91 __kmpc_omp_task_with_deps(Loc, TId, TaskDescriptor, 0, 0, 0, 0);
92}
93
94int omp_in_final(void) {
95 // treat all tasks as final... Specs may expect runtime to keep
96 // track more precisely if a task was actively set by users... This
97 // is not explicitly specified; will treat as if runtime can
98 // actively decide to put a non-final task into a final one.
99 return 1;
100}
101
102int omp_get_max_task_priority(void) { return 0; }
103}
104

source code of offload/DeviceRTL/src/Tasking.cpp