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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Tests should not use rand()"
href="https://llvm.org/bugs/show_bug.cgi?id=31730">31730</a>
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<th>Summary</th>
<td>Tests should not use rand()
</td>
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<th>Product</th>
<td>Test Suite
</td>
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>All
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Programs Tests
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>matze@braunis.de
</td>
</tr>
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
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<th>Classification</th>
<td>Unclassified
</td>
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<p>
<div>
<pre>rand() can produce different numbers with different libc implementations.
Therefore we should not use it in the test-suite to get portable tests. Today a
test like this:
$ grep "\<rand\s*()" SingleSource/ MultiSource/ -r
shows 54 affected files. We should probably write a simple everything in one
header random number generator and replace the rand() usage with that in the
tests.
There is an additional problem of benchmarks that do not even use srand() to
get a deterministic random number sequence from run to run. We spotted this
benchmarking anti-pattern in SingleSource//UnitTests/SignlessTypes/rem.c but
the other benchmarks should be audited for that as well.</pre>
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