1// RUN: %libomp-cxx-compile-and-run
2
3#include <stdio.h>
4#include <omp.h>
5
6#define NT 4
7#define INIT 10
8
9/*
10The test emulates code generation needed for reduction with task modifier on
11parallel construct.
12
13Note: tasks could just use in_reduction clause, but compiler does not accept
14this because of bug: it mistakenly requires reduction item to be shared, which
15is only true for reduction on worksharing and wrong for task reductions.
16*/
17
18//------------------------------------------------
19// OpenMP runtime library routines
20#ifdef __cplusplus
21extern "C" {
22#endif
23extern void *__kmpc_task_reduction_get_th_data(int gtid, void *tg, void *item);
24// extern void* __kmpc_task_reduction_modifier_init(void *loc, int gtid, int
25// flags, int num, void* data);
26extern void *__kmpc_taskred_modifier_init(void *loc, int gtid, int is_ws,
27 int num, void *data);
28extern void __kmpc_task_reduction_modifier_fini(void *loc, int gtid, int is_ws);
29extern int __kmpc_global_thread_num(void *);
30#ifdef __cplusplus
31}
32#endif
33
34//------------------------------------------------
35// Compiler-generated code
36
37typedef struct red_input {
38 void *reduce_shar; /**< shared between tasks item to reduce into */
39 void *reduce_orig; /**< original reduction item used for initialization */
40 size_t reduce_size; /**< size of data item in bytes */
41 // three compiler-generated routines (init, fini are optional):
42 void *reduce_init; /**< data initialization routine (single parameter) */
43 void *reduce_fini; /**< data finalization routine */
44 void *reduce_comb; /**< data combiner routine */
45 unsigned flags; /**< flags for additional info from compiler */
46} red_input_t;
47
48void i_comb(void *lhs, void *rhs) { *(int *)lhs += *(int *)rhs; }
49
50int main() {
51 int var = INIT;
52 int *p_var_orig = &var;
53 int i;
54 omp_set_dynamic(0);
55 omp_set_num_threads(NT);
56#pragma omp parallel private(i) shared(p_var_orig)
57// #pragma omp for reduction(task,+:var)
58#pragma omp for reduction(+ : var)
59 for (i = 0; i < NT; ++i) // single iteration per thread
60 {
61 // generated code, which actually should be placed before
62 // loop iterations distribution, but placed here just to show the idea,
63 // and to keep correctness the loop count is equal to number of threads
64 int gtid = __kmpc_global_thread_num(NULL);
65 void *tg; // pointer to taskgroup (optional)
66 red_input_t r_var;
67 r_var.reduce_shar = &var;
68 r_var.reduce_orig =
69 p_var_orig; // not used in this test but illustrates codegen
70 r_var.reduce_size = sizeof(var);
71 r_var.reduce_init = NULL;
72 r_var.reduce_fini = NULL;
73 r_var.reduce_comb = (void *)&i_comb;
74 tg = __kmpc_taskred_modifier_init(
75 NULL, // ident_t loc;
76 gtid,
77 is_ws: 1, // 1 - worksharing construct, 0 - parallel
78 num: 1, // number of reduction objects
79 data: &r_var // related data
80 );
81 // end of generated code
82 var++;
83#pragma omp task /*in_reduction(+:var)*/ shared(var)
84 {
85 // emulate task reduction here because of compiler bug:
86 // it mistakenly declines to accept in_reduction because var is private
87 // outside.
88 int gtid = __kmpc_global_thread_num(NULL);
89 int *p_var = (int *)__kmpc_task_reduction_get_th_data(gtid, tg, item: &var);
90 *p_var += 1;
91 }
92 if (omp_get_thread_num() > 0) {
93#pragma omp task /*in_reduction(+:var)*/ shared(var)
94 {
95 int gtid = __kmpc_global_thread_num(NULL);
96 int *p_var = (int *)__kmpc_task_reduction_get_th_data(gtid, tg, item: &var);
97 *p_var += 1;
98 }
99 }
100 // generated code, which actually should be placed after loop completion
101 // but before barrier and before loop reduction. It placed here just to show
102 // the idea,
103 // and to keep correctness the loop count is equal to number of threads
104 __kmpc_task_reduction_modifier_fini(NULL, gtid, is_ws: 1);
105 // end of generated code
106 }
107 if (var == INIT + NT * 3 - 1) {
108 printf(format: "passed\n");
109 return 0;
110 } else {
111 printf(format: "failed: var = %d (!= %d)\n", var, INIT + NT * 3 - 1);
112 return 1;
113 }
114}
115

source code of openmp/runtime/test/tasking/kmp_task_modifier_simple_ws_new.cpp