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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Failure to optimize certain kind of always-true comparisons"
href="https://bugs.llvm.org/show_bug.cgi?id=45510">45510</a>
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<th>Summary</th>
<td>Failure to optimize certain kind of always-true comparisons
</td>
</tr>
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<th>Product</th>
<td>libraries
</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>Linux
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Scalar Optimizations
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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</tr>
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<th>Reporter</th>
<td>gabravier@gmail.com
</td>
</tr>
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
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<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=23342" name="attach_23342" title="Contains files helping to reproduce the bug (not very helpful if you don't have a development version of gcc)">attachment 23342</a> <a href="attachment.cgi?id=23342&action=edit" title="Contains files helping to reproduce the bug (not very helpful if you don't have a development version of gcc)">[details]</a></span>
Contains files helping to reproduce the bug (not very helpful if you don't have
a development version of gcc)
Operations such as `x >= y || x == UINT_MAX` are not converted to `x >= y` by
LLVM, where GCC does as such.
Comparison here: <a href="https://godbolt.org/z/4-cyjG">https://godbolt.org/z/4-cyjG</a>
I have attached an comparison archive, though it is not very useful right now
as the optimization hasn't made it into a GCC release yet (if you want, I can
add an updated archive once gcc 10.1 is released). The Godbolt comparison
better helps visualise the difference between GCC and clang here.
Notes:
- The archive's gcc.s file does not contain the optimizations. This is because
these optimizations are from gcc 10.0 (pre-release branch), and gcc.s was
generated with gcc 9.3. However, I would expect gcc >= 10.1 to have this
optimization.</pre>
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