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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - 32bit Linux, the assignment operator of vector value cause FPU stack over-flow."
href="http://llvm.org/bugs/show_bug.cgi?id=15388">15388</a>
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<th>Summary</th>
<td>32bit Linux, the assignment operator of vector value cause FPU stack over-flow.
</td>
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<th>Product</th>
<td>clang
</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>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>LLVM Codegen
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
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<th>Reporter</th>
<td>qiancong@multicorewareinc.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>Created <span class=""><a href="attachment.cgi?id=10104" name="attach_10104" title="A bug test code">attachment 10104</a> <a href="attachment.cgi?id=10104&action=edit" title="A bug test code">[details]</a></span>
A bug test code
In 32bit Linux, asignment operator or pass argument for the vector type value
defined by ext_vector, may cause FPU register stack over-flow, thus some
following float operator get not correct result!
analyze the attached demo code(int 32bit Linux Box):
from the disassembled code, we found that clang generate asm code like
"movq mm0, [esp+4]" for char8/uchar8 asignment operator, but no "EMMS"
instruction to reset, so cause FPU register stack over-flow , if any float
operator was followed, maybe cause the float result not correct..
I have test this demo code by clang3.2 and clang3.3, can represent the bug..
Any fix or update of the bug, please tell me. I will very appreciate　for your
help.</pre>
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