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<body><span class="vcard"><a class="email" href="mailto:david.majnemer@gmail.com" title="David Majnemer <david.majnemer@gmail.com>"> <span class="fn">David Majnemer</span></a>
</span> changed
<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED INVALID - strlen (s) == 0 not folded when return type is casted to unsigned"
href="https://llvm.org/bugs/show_bug.cgi?id=28833">bug 28833</a>
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<th>What</th>
<th>Removed</th>
<th>Added</th>
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<td style="text-align:right;">Status</td>
<td>NEW
</td>
<td>RESOLVED
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<td style="text-align:right;">CC</td>
<td>
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<td>david.majnemer@gmail.com
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<td style="text-align:right;">Resolution</td>
<td>---
</td>
<td>INVALID
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<b><a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED INVALID - strlen (s) == 0 not folded when return type is casted to unsigned"
href="https://llvm.org/bugs/show_bug.cgi?id=28833#c1">Comment # 1</a>
on <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED INVALID - strlen (s) == 0 not folded when return type is casted to unsigned"
href="https://llvm.org/bugs/show_bug.cgi?id=28833">bug 28833</a>
from <span class="vcard"><a class="email" href="mailto:david.majnemer@gmail.com" title="David Majnemer <david.majnemer@gmail.com>"> <span class="fn">David Majnemer</span></a>
</span></b>
<pre>It is not correct to transform ((unsigned)__builtin_strlen(s)) == 0 into *s ==
0.
The unsigned cast is masking out the high half of the strlen result.
For example, if __builtin_strlen comes out to 1ULL << 32 then
(unsigned)__builtin_strlen is zero but *s isn't 0.</pre>
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