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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [OPENMP 4.5]"
href="https://bugs.llvm.org/show_bug.cgi?id=50733">50733</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[OPENMP 4.5]
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>10.0
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>OpenMP
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>xiao.liu@compiler-dev.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>The testcase is,
#include <stdio.h>
#define M 10
int b = 10;
int main()
{
int a[M], i;
#pragma omp parallel
{
#pragma omp for linear(b:2)
for (i = 0; i < M; i++) {
a[i] = b;
}
}
for (i = 0; i < M; i++) {
printf("%d ", a[i]);
}
printf("\n%d\n", b);
return 0;
}
The result is,
10 12 14 16 18 20 22 24 26 28
final b: 30
See OpenMP 4.5 specification, 2.15.3.7
"When a linear clause is specified on a construct,(...),The value corresponding
to the sequentially last iteration of the associated loop(s) is assigned to the
original list item."
I think that the final value of 'b' should be 28. And if there is some
assignment to 'b' in the loop, like as,
#pragma omp for linear(b:2)
for (i = 0; i < M; i++) {
a[i] = b;
b += 2;
}
The final value of 'b' should be calculate as, (28+2)=30, instead of
(10+M*2)=30.</pre>
</div>
</p>
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