parallel-reduction-nowait.c

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/*
 * parallel-reduction-nowait.c -- Archer testcase
 */
 
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
//
// See tools/archer/LICENSE.txt for details.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
 
 
// RUN: %libarcher-compile-and-run | FileCheck %s
// REQUIRES: tsan
#include <omp.h>
#include <stdio.h>
 
int main(int argc, char *argv[]) {
  int var = 0, i;
  int sum1 = 0;
  int sum2 = 0;
 
// Number of threads is empirical: We need enough threads so that
// the reduction is really performed hierarchically in the barrier!
#pragma omp parallel num_threads(5) reduction(+ : var)
  {
#pragma omp for schedule(static) nowait reduction(+ : sum1)
    for (i = 0; i < 5; i++)
      sum1 += i;
#pragma omp for schedule(static) reduction(+ : sum2)
    for (i = 0; i < 5; i++)
      sum2 += i;
 
    var = sum1 + sum2;
  }
 
  fprintf(stderr, "DONE\n");
  int error = (var != 100);
  return error;
}
 
// CHECK-NOT: ThreadSanitizer: data race
// CHECK-NOT: ThreadSanitizer: reported
// CHECK: DONE