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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - llc doesn't optimize load from XMM well enough."
href="http://llvm.org/bugs/show_bug.cgi?id=18344">18344</a>
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<th>Summary</th>
<td>llc doesn't optimize load from XMM well enough.
</td>
</tr>
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<th>Product</th>
<td>tools
</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>normal
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>llc
</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>ili.filippov@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
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<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=11798" name="attach_11798" title="Reproducer">attachment 11798</a> <a href="attachment.cgi?id=11798&action=edit" title="Reproducer">[details]</a></span>
Reproducer
This issue is reproducible with LLVM trunk.
The reproducer is attached.
Command to reproduce: llc -O2 reproducer.ll
llc generates the sequence of instructions:
vmovdqa %xmm0, -24(%rsp)
movslq -24(%rsp), %rax
movslq -20(%rsp), %rcx
movslq -16(%rsp), %rdx
movslq -12(%rsp), %r8
but it seems that another sequence of instructions will be more efficient:
vpextrd $0, %xmm0, %rax
vpextrd $1, %xmm0, %rcx
vpextrd $2, %xmm0, %rdx
vpextrd $3, %xmm0, %r8</pre>
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