doxygen/target__thread__limit_8cpp_source.html

// RUN: %libomp-cxx-compile -fopenmp-version=51

// RUN: %libomp-run | FileCheck %s --check-prefix OMP51


#include <stdio.h>

#include <omp.h>


void foo() {

#pragma omp parallel num_threads(10)

  { printf("\ntarget: foo(): parallel num_threads(10)"); }

}


int main(void) {


  int tl = 4;

  printf("\nmain: thread_limit = %d", omp_get_thread_limit());

  // OMP51: main: thread_limit = {{[0-9]+}}


#pragma omp target thread_limit(tl)

  {

    printf("\ntarget: thread_limit = %d", omp_get_thread_limit());

    int count = 0;

// OMP51: target: thread_limit = 4

// check whether thread_limit is honoured

#pragma omp parallel reduction(+:count)

    { count++; }

    printf("\ntarget: parallel: count = %d", count);

// OMP51: target: parallel: count = {{(1|2|3|4)$}}


// check whether num_threads is honoured

#pragma omp parallel num_threads(2)

    { printf("\ntarget: parallel num_threads(2)"); }

// OMP51: target: parallel num_threads(2)

// OMP51: target: parallel num_threads(2)

// OMP51-NOT: target: parallel num_threads(2)


// check whether thread_limit is honoured when there is a conflicting

// num_threads

#pragma omp parallel num_threads(10)

    { printf("\ntarget: parallel num_threads(10)"); }

    // OMP51: target: parallel num_threads(10)

    // OMP51: target: parallel num_threads(10)

    // OMP51: target: parallel num_threads(10)

    // OMP51: target: parallel num_threads(10)

    // OMP51-NOT: target: parallel num_threads(10)


    // check whether threads are limited across functions

    foo();

    // OMP51: target: foo(): parallel num_threads(10)

    // OMP51: target: foo(): parallel num_threads(10)

    // OMP51: target: foo(): parallel num_threads(10)

    // OMP51: target: foo(): parallel num_threads(10)

    // OMP51-NOT: target: foo(): parallel num_threads(10)


    // check if user can set num_threads at runtime

    omp_set_num_threads(2);

#pragma omp parallel

    { printf("\ntarget: parallel with omp_set_num_thread(2)"); }

    // OMP51: target: parallel with omp_set_num_thread(2)

    // OMP51: target: parallel with omp_set_num_thread(2)

    // OMP51-NOT: target: parallel with omp_set_num_thread(2)


    // make sure thread_limit is unaffected by omp_set_num_threads

    printf("\ntarget: thread_limit = %d", omp_get_thread_limit());

    // OMP51: target: thread_limit = 4

  }


// checking consecutive target regions with different thread_limits

#pragma omp target thread_limit(3)

  {

    printf("\nsecond target: thread_limit = %d", omp_get_thread_limit());

    int count = 0;

// OMP51: second target: thread_limit = 3

#pragma omp parallel reduction(+:count)

    { count++; }

    printf("\nsecond target: parallel: count = %d", count);

    // OMP51: second target: parallel: count = {{(1|2|3)$}}

  }


  // confirm that thread_limit's effects are limited to target region

  printf("\nmain: thread_limit = %d", omp_get_thread_limit());

  // OMP51: main: thread_limit = {{[0-9]+}}

#pragma omp parallel num_threads(10)

  { printf("\nmain: parallel num_threads(10)"); }

  // OMP51: main: parallel num_threads(10)

  // OMP51: main: parallel num_threads(10)

  // OMP51: main: parallel num_threads(10)

  // OMP51: main: parallel num_threads(10)

  // OMP51: main: parallel num_threads(10)

  // OMP51: main: parallel num_threads(10)

  // OMP51: main: parallel num_threads(10)

  // OMP51: main: parallel num_threads(10)

  // OMP51: main: parallel num_threads(10)

  // OMP51: main: parallel num_threads(10)

  // OMP51-NOT: main: parallel num_threads(10)


// check combined target directives which support thread_limit

// target parallel

#pragma omp target parallel thread_limit(2)

  printf("\ntarget parallel thread_limit(2)");

  // OMP51: target parallel thread_limit(2)

  // OMP51: target parallel thread_limit(2)

  // OMP51-NOT: target parallel thread_limit(2)


#pragma omp target parallel num_threads(2) thread_limit(3)

  printf("\ntarget parallel num_threads(2) thread_limit(3)");

  // OMP51: target parallel num_threads(2) thread_limit(3)

  // OMP51: target parallel num_threads(2) thread_limit(3)

  // OMP51-NOT: target parallel num_threads(2) thread_limit(3)


#pragma omp target parallel num_threads(3) thread_limit(2)

  printf("\ntarget parallel num_threads(3) thread_limit(2)");

  // OMP51: target parallel num_threads(3) thread_limit(2)

  // OMP51: target parallel num_threads(3) thread_limit(2)

  // OMP51-NOT: target parallel num_threads(3) thread_limit(2)


// target parallel for

#pragma omp target parallel for thread_limit(2)

  for (int i = 0; i < 5; ++i)

    printf("\ntarget parallel for thread_limit(2) : thread num = %d",

           omp_get_thread_num());

    // OMP51: target parallel for thread_limit(2) : thread num = {{0|1}}

    // OMP51: target parallel for thread_limit(2) : thread num = {{0|1}}

    // OMP51: target parallel for thread_limit(2) : thread num = {{0|1}}

    // OMP51: target parallel for thread_limit(2) : thread num = {{0|1}}

    // OMP51: target parallel for thread_limit(2) : thread num = {{0|1}}

    // OMP51-NOT: target parallel for thread_limit(3) : thread num = {{0|1}}


// target parallel for simd

#pragma omp target parallel for simd thread_limit(2)

  for (int i = 0; i < 5; ++i)

    printf("\ntarget parallel for simd thread_limit(2) : thread num = %d",

           omp_get_thread_num());

    // OMP51: target parallel for simd thread_limit(2) : thread num = {{0|1}}

    // OMP51: target parallel for simd thread_limit(2) : thread num = {{0|1}}

    // OMP51: target parallel for simd thread_limit(2) : thread num = {{0|1}}

    // OMP51: target parallel for simd thread_limit(2) : thread num = {{0|1}}

    // OMP51: target parallel for simd thread_limit(2) : thread num = {{0|1}}

    // OMP51-NOT: target parallel for simd thread_limit(2) : thread num =

    // {{0|1}}


// target simd

#pragma omp target simd thread_limit(2)

  for (int i = 0; i < 5; ++i)

    printf("\ntarget simd thread_limit(2) : thread num = %d",

           omp_get_thread_num());

    // OMP51: target simd thread_limit(2) : thread num = {{0|1}}

    // OMP51: target simd thread_limit(2) : thread num = {{0|1}}

    // OMP51: target simd thread_limit(2) : thread num = {{0|1}}

    // OMP51: target simd thread_limit(2) : thread num = {{0|1}}

    // OMP51: target simd thread_limit(2) : thread num = {{0|1}}

    // OMP51-NOT: target simd thread_limit(2) : thread num = {{0|1}}


// target parallel loop

#pragma omp target parallel loop thread_limit(2)

  for (int i = 0; i < 5; ++i)

    printf("\ntarget parallel loop thread_limit(2) : thread num = %d",

           omp_get_thread_num());

  // # OMP51: target parallel loop thread_limit(2) : thread num = {{0|1}}

  // # OMP51: target parallel loop thread_limit(2) : thread num = {{0|1}}

  // # OMP51: target parallel loop thread_limit(2) : thread num = {{0|1}}

  // # OMP51: target parallel loop thread_limit(2) : thread num = {{0|1}}

  // # OMP51: target parallel loop thread_limit(2) : thread num = {{0|1}}

  // # OMP51-NOT: target parallel loop thread_limit(2) : thread num = {{0|1}}

  return 0;

}

count
void const char const char int ITT_FORMAT __itt_group_sync x void const char ITT_FORMAT __itt_group_sync s void ITT_FORMAT __itt_group_sync p void ITT_FORMAT p void ITT_FORMAT p no args __itt_suppress_mode_t unsigned int void size_t ITT_FORMAT d void ITT_FORMAT p void ITT_FORMAT p __itt_model_site __itt_model_site_instance ITT_FORMAT p __itt_model_task __itt_model_task_instance ITT_FORMAT p void ITT_FORMAT p void ITT_FORMAT p void size_t ITT_FORMAT d void ITT_FORMAT p const wchar_t ITT_FORMAT s const char ITT_FORMAT s const char ITT_FORMAT s const char ITT_FORMAT s no args void ITT_FORMAT p size_t count
Definition: ittnotify_static.h:282

i
#define i
Definition: kmp_stub.cpp:87

omp_set_num_threads
#define omp_set_num_threads
Definition: kmp_stub.cpp:34

main
int main(void)
Definition: target_thread_limit.cpp:12

foo
void foo()
Definition: target_thread_limit.cpp:7