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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Exploit LRVH/STRVH/MVCIN for byte swaps"
href="https://llvm.org/bugs/show_bug.cgi?id=23420">23420</a>
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<th>Summary</th>
<td>Exploit LRVH/STRVH/MVCIN for byte swaps
</td>
</tr>
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<th>Product</th>
<td>libraries
</td>
</tr>
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>Other
</td>
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<th>OS</th>
<td>Linux
</td>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Backend: SystemZ
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
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<th>Reporter</th>
<td>uweigand@de.ibm.com
</td>
</tr>
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<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>System z currently uses the word and doubleword forms of LOAD REVERSED
and STORE REVERSED to optimize byte-swap idioms.
However, the architecture also provides halfword forms of those
instructions which could be exploited likewise.
In addition, the architecture provides a MOVE INVERSE instruction that
can be used to implement a direct memory-to-memory version of byte-swap
(of any length, in particular including halfword, word, and doubleword).</pre>
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</p>
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