openmp/runtime/test/tasking/omp_task_red_taskloop.c

   1 // RUN: %libomp-compile-and-run
   2
   3 // Parsing error until gcc8:
   4 // UNSUPPORTED: gcc-4, gcc-5, gcc-6, gcc-7, gcc-8
   5
   6 // Parsing error until clang11:
   7 // UNSUPPORTED: clang-10, clang-9, clang-8, clang-7
   8
   9 // No icc compiler support yet
  10 // XFAIL: icc
  11
  12 #include <stdio.h>
  13 #include <omp.h>
  14
  15 int r;
  16
  17 int work(int k, int l)
  18 {
  19   return k + l + 1;
  20 }
  21 void bar(int i) {
  22   #pragma omp taskgroup task_reduction(+:r)
  23  { int th_gen = omp_get_thread_num();
  24   #pragma omp task in_reduction(+:r) firstprivate(i, th_gen)
  25   {
  26     r += work(i, 0);
  27 printf("executing task (%d, 0), th %d (gen by th %d)\n", i, omp_get_thread_num(), th_gen);
  28   }
  29   #pragma omp task in_reduction(+:r) firstprivate(i, th_gen)
  30   {
  31     r += work(i, 1);
  32 printf("executing task (%d, 1), th %d (gen by th %d)\n", i, omp_get_thread_num(), th_gen);
  33   }
  34  }
  35 }
  36 int foo() {
  37   int i;
  38   int th_gen = omp_get_thread_num();
  39   #pragma omp taskgroup task_reduction(+:r)
  40   {
  41     bar(0);
  42   }
  43 printf("th %d passed bar0\n", th_gen);
  44   #pragma omp taskloop reduction(+:r) firstprivate(th_gen)
  45   for (i = 1; i < 4; ++i) {
  46     bar(i);
  47 printf("th %d (gen by th %d) passed bar%d in taskloop\n", omp_get_thread_num(), th_gen, i);
  48   #pragma omp task in_reduction(+:r)
  49     r += i;
  50   }
  51   return 0;
  52 }
  53 // res = ((1+2)+(2+3)+(3+4)+(4+5)+1+2+3) = 30
  54 #define res 30
  55 int main()
  56 {
  57   r = 0;
  58   #pragma omp parallel num_threads(2)
  59   { // barrier ensures threads have started before tasks creation
  60     #pragma omp barrier
  61     // single ensures no race condition between taskgroup reductions
  62     #pragma omp single nowait
  63       foo();
  64   }
  65   if (r == res) {
  66     return 0;
  67   } else {
  68     printf("error r = %d (!= %d)\n", r, res);
  69     return 1;
  70   }
  71 }