openmp/runtime/test/target/target_thread_limit.cpp

   1 // RUN: %libomp-cxx-compile -fopenmp-version=51
   2 // RUN: %libomp-run | FileCheck %s --check-prefix OMP51
   3
   4 #include <stdio.h>
   5 #include <omp.h>
   6
   7 void foo() {
   8 #pragma omp parallel num_threads(10)
   9   { printf("\ntarget: foo(): parallel num_threads(10)"); }
  10 }
  11
  12 int main(void) {
  13
  14   int tl = 4;
  15   printf("\nmain: thread_limit = %d", omp_get_thread_limit());
  16   // OMP51: main: thread_limit = {{[0-9]+}}
  17
  18 #pragma omp target thread_limit(tl)
  19   {
  20     printf("\ntarget: thread_limit = %d", omp_get_thread_limit());
  21     int count = 0;
  22 // OMP51: target: thread_limit = 4
  23 // check whether thread_limit is honoured
  24 #pragma omp parallel reduction(+:count)
  25     { count++; }
  26     printf("\ntarget: parallel: count = %d", count);
  27 // OMP51: target: parallel: count = {{(1|2|3|4)$}}
  28
  29 // check whether num_threads is honoured
  30 #pragma omp parallel num_threads(2)
  31     { printf("\ntarget: parallel num_threads(2)"); }
  32 // OMP51: target: parallel num_threads(2)
  33 // OMP51: target: parallel num_threads(2)
  34 // OMP51-NOT: target: parallel num_threads(2)
  35
  36 // check whether thread_limit is honoured when there is a conflicting
  37 // num_threads
  38 #pragma omp parallel num_threads(10)
  39     { printf("\ntarget: parallel num_threads(10)"); }
  40     // OMP51: target: parallel num_threads(10)
  41     // OMP51: target: parallel num_threads(10)
  42     // OMP51: target: parallel num_threads(10)
  43     // OMP51: target: parallel num_threads(10)
  44     // OMP51-NOT: target: parallel num_threads(10)
  45
  46     // check whether threads are limited across functions
  47     foo();
  48     // OMP51: target: foo(): parallel num_threads(10)
  49     // OMP51: target: foo(): parallel num_threads(10)
  50     // OMP51: target: foo(): parallel num_threads(10)
  51     // OMP51: target: foo(): parallel num_threads(10)
  52     // OMP51-NOT: target: foo(): parallel num_threads(10)
  53
  54     // check if user can set num_threads at runtime
  55     omp_set_num_threads(2);
  56 #pragma omp parallel
  57     { printf("\ntarget: parallel with omp_set_num_thread(2)"); }
  58     // OMP51: target: parallel with omp_set_num_thread(2)
  59     // OMP51: target: parallel with omp_set_num_thread(2)
  60     // OMP51-NOT: target: parallel with omp_set_num_thread(2)
  61
  62     // make sure thread_limit is unaffected by omp_set_num_threads
  63     printf("\ntarget: thread_limit = %d", omp_get_thread_limit());
  64     // OMP51: target: thread_limit = 4
  65   }
  66
  67 // checking consecutive target regions with different thread_limits
  68 #pragma omp target thread_limit(3)
  69   {
  70     printf("\nsecond target: thread_limit = %d", omp_get_thread_limit());
  71     int count = 0;
  72 // OMP51: second target: thread_limit = 3
  73 #pragma omp parallel reduction(+:count)
  74     { count++; }
  75     printf("\nsecond target: parallel: count = %d", count);
  76     // OMP51: second target: parallel: count = {{(1|2|3)$}}
  77   }
  78
  79   // confirm that thread_limit's effects are limited to target region
  80   printf("\nmain: thread_limit = %d", omp_get_thread_limit());
  81   // OMP51: main: thread_limit = {{[0-9]+}}
  82 #pragma omp parallel num_threads(10)
  83   { printf("\nmain: parallel num_threads(10)"); }
  84   // OMP51: main: parallel num_threads(10)
  85   // OMP51: main: parallel num_threads(10)
  86   // OMP51: main: parallel num_threads(10)
  87   // OMP51: main: parallel num_threads(10)
  88   // OMP51: main: parallel num_threads(10)
  89   // OMP51: main: parallel num_threads(10)
  90   // OMP51: main: parallel num_threads(10)
  91   // OMP51: main: parallel num_threads(10)
  92   // OMP51: main: parallel num_threads(10)
  93   // OMP51: main: parallel num_threads(10)
  94   // OMP51-NOT: main: parallel num_threads(10)
  95
  96 // check combined target directives which support thread_limit
  97 // target parallel
  98 #pragma omp target parallel thread_limit(2)
  99   printf("\ntarget parallel thread_limit(2)");
 100   // OMP51: target parallel thread_limit(2)
 101   // OMP51: target parallel thread_limit(2)
 102   // OMP51-NOT: target parallel thread_limit(2)
 103
 104 #pragma omp target parallel num_threads(2) thread_limit(3)
 105   printf("\ntarget parallel num_threads(2) thread_limit(3)");
 106   // OMP51: target parallel num_threads(2) thread_limit(3)
 107   // OMP51: target parallel num_threads(2) thread_limit(3)
 108   // OMP51-NOT: target parallel num_threads(2) thread_limit(3)
 109
 110 #pragma omp target parallel num_threads(3) thread_limit(2)
 111   printf("\ntarget parallel num_threads(3) thread_limit(2)");
 112   // OMP51: target parallel num_threads(3) thread_limit(2)
 113   // OMP51: target parallel num_threads(3) thread_limit(2)
 114   // OMP51-NOT: target parallel num_threads(3) thread_limit(2)
 115
 116 // target parallel for
 117 #pragma omp target parallel for thread_limit(2)
 118   for (int i = 0; i < 5; ++i)
 119     printf("\ntarget parallel for thread_limit(2) : thread num = %d",
 120            omp_get_thread_num());
 121     // OMP51: target parallel for thread_limit(2) : thread num = {{0|1}}
 122     // OMP51: target parallel for thread_limit(2) : thread num = {{0|1}}
 123     // OMP51: target parallel for thread_limit(2) : thread num = {{0|1}}
 124     // OMP51: target parallel for thread_limit(2) : thread num = {{0|1}}
 125     // OMP51: target parallel for thread_limit(2) : thread num = {{0|1}}
 126     // OMP51-NOT: target parallel for thread_limit(3) : thread num = {{0|1}}
 127
 128 // target parallel for simd
 129 #pragma omp target parallel for simd thread_limit(2)
 130   for (int i = 0; i < 5; ++i)
 131     printf("\ntarget parallel for simd thread_limit(2) : thread num = %d",
 132            omp_get_thread_num());
 133     // OMP51: target parallel for simd thread_limit(2) : thread num = {{0|1}}
 134     // OMP51: target parallel for simd thread_limit(2) : thread num = {{0|1}}
 135     // OMP51: target parallel for simd thread_limit(2) : thread num = {{0|1}}
 136     // OMP51: target parallel for simd thread_limit(2) : thread num = {{0|1}}
 137     // OMP51: target parallel for simd thread_limit(2) : thread num = {{0|1}}
 138     // OMP51-NOT: target parallel for simd thread_limit(2) : thread num =
 139     // {{0|1}}
 140
 141 // target simd
 142 #pragma omp target simd thread_limit(2)
 143   for (int i = 0; i < 5; ++i)
 144     printf("\ntarget simd thread_limit(2) : thread num = %d",
 145            omp_get_thread_num());
 146     // OMP51: target simd thread_limit(2) : thread num = {{0|1}}
 147     // OMP51: target simd thread_limit(2) : thread num = {{0|1}}
 148     // OMP51: target simd thread_limit(2) : thread num = {{0|1}}
 149     // OMP51: target simd thread_limit(2) : thread num = {{0|1}}
 150     // OMP51: target simd thread_limit(2) : thread num = {{0|1}}
 151     // OMP51-NOT: target simd thread_limit(2) : thread num = {{0|1}}
 152
 153 // target parallel loop
 154 #pragma omp target parallel loop thread_limit(2)
 155   for (int i = 0; i < 5; ++i)
 156     printf("\ntarget parallel loop thread_limit(2) : thread num = %d",
 157            omp_get_thread_num());
 158   // # OMP51: target parallel loop thread_limit(2) : thread num = {{0|1}}
 159   // # OMP51: target parallel loop thread_limit(2) : thread num = {{0|1}}
 160   // # OMP51: target parallel loop thread_limit(2) : thread num = {{0|1}}
 161   // # OMP51: target parallel loop thread_limit(2) : thread num = {{0|1}}
 162   // # OMP51: target parallel loop thread_limit(2) : thread num = {{0|1}}
 163   // # OMP51-NOT: target parallel loop thread_limit(2) : thread num = {{0|1}}
 164   return 0;
 165 }