openmp/tools/archer/tests/reduction/parallel-reduction.c

   1 /*
   2  * parallel-reduction.c -- Archer testcase
   3  */
   4
   5 //===----------------------------------------------------------------------===//
   6 //
   7 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   8 //
   9 // See tools/archer/LICENSE.txt for details.
  10 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14
  15 // RUN: %libarcher-compile-and-run| FileCheck %s
  16 // REQUIRES: tsan
  17 #include <omp.h>
  18 #include <stdio.h>
  19
  20 int main(int argc, char *argv[]) {
  21   int var = 0;
  22
  23 // Number of threads is empirical: We need enough threads so that
  24 // the reduction is really performed hierarchically in the barrier!
  25 #pragma omp parallel num_threads(5) reduction(+ : var)
  26   { var = 1; }
  27
  28   fprintf(stderr, "DONE\n");
  29   int error = (var != 5);
  30   return error;
  31 }
  32
  33 // CHECK-NOT: ThreadSanitizer: data race
  34 // CHECK-NOT: ThreadSanitizer: reported
  35 // CHECK: DONE