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<base href="http://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Clang cannot do LTO with BMI2 instructions"
href="http://llvm.org/bugs/show_bug.cgi?id=19416">19416</a>
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<th>Summary</th>
<td>Clang cannot do LTO with BMI2 instructions
</td>
</tr>
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<th>Product</th>
<td>clang
</td>
</tr>
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<th>Version</th>
<td>3.4
</td>
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<th>Hardware</th>
<td>Macintosh
</td>
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<th>OS</th>
<td>MacOS X
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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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>LLVM Codegen
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
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<th>Reporter</th>
<td>services@daylenyang.com
</td>
</tr>
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<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
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<div>
<pre>Created <span class=""><a href="attachment.cgi?id=12368" name="attach_12368" title="Test file with a BMI2 instruction.">attachment 12368</a> <a href="attachment.cgi?id=12368&action=edit" title="Test file with a BMI2 instruction.">[details]</a></span>
Test file with a BMI2 instruction.
Overview:
Clang cannot do LTO (link time optimization) when there are BMI2 instructions
in the file.
Steps to reproduce:
0. Make sure you have an Intel Haswell processor.
1. Create a simple C program (such as the one attached) that contains a BMI2
intrinsic such as _pext_u32(). Be sure to include <x86intrin.h>.
2. Compile using command: clang -mbmi2 file_name.c
3. Compile using command: clang -mbmi2 -flto file_name.c
Actual results:
Compiling without LTO works great. Compiling using LTO crashes with this error:
LLVM ERROR: Cannot select: intrinsic %llvm.x86.bmi.pext.32
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Expected results:
Clang should be able to compile the file with LTO.
Version:
Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn)
Target: x86_64-apple-darwin13.1.0
Thread model: posix</pre>
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