<html>
<head>
<base href="https://bugs.llvm.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - combined target teams implements shared clause as firstprivate"
href="https://bugs.llvm.org/show_bug.cgi?id=40253">40253</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>combined target teams implements shared clause as firstprivate
</td>
</tr>
<tr>
<th>Product</th>
<td>OpenMP
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Clang Compiler Support
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>jdenny.ornl@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>a.bataev@hotmail.com, llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>Clang implements `shared(n)` on `omp target teams` as firstprivate instead of
shared. For example, n is not shared in the following example:
```
$ cat test.c
#include <omp.h>
#include <stdio.h>
int main() {
int n = 0;
#pragma omp target teams shared(n) num_teams(2)
#pragma omp parallel num_threads(1)
{
#pragma omp atomic update
++n;
printf("n=%d, team=%d\n", n, omp_get_team_num());
}
return 0;
}
$ clang -fopenmp test.c && ./a.out
n=1, team=0
n=1, team=1
```
However, if I split the `target teams` directive into two directives, I see
results indicating n is shared:
```
$ cat test.c
#include <omp.h>
#include <stdio.h>
int main() {
int n = 0;
#pragma omp target
#pragma omp teams shared(n) num_teams(2)
#pragma omp parallel num_threads(1)
{
#pragma omp atomic update
++n;
printf("n=%d, team=%d\n", n, omp_get_team_num());
}
return 0;
}
$ clang -fopenmp test.c && ./a.out
n=1, team=0
n=2, team=1
```
The LLVM IR shows that n is passed to the teams by value in the first case and
by pointer in the second.
This bugzilla was suggested at:
<a href="https://reviews.llvm.org/D56113#1345047">https://reviews.llvm.org/D56113#1345047</a></pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>