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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - invalid symbol redefinition when -O2 enabled"
href="https://bugs.llvm.org/show_bug.cgi?id=51308">51308</a>
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<th>Summary</th>
<td>invalid symbol redefinition when -O2 enabled
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>C
</td>
</tr>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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</tr>
<tr>
<th>Reporter</th>
<td>zhan3299@purdue.edu
</td>
</tr>
<tr>
<th>CC</th>
<td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<p>
<div>
<pre>Following code can be successfully compiled by O0 optimization on, but not O2.
Example code:
---
#include <stdio.h>
int func() {
int filter;
asm volatile(
" leaq _filter(%%rip), %%rax\n"
" jmp _out\n"
"_filter:\n"
".ascii \"\\040\"\n"
"_out:"
: "=rax"(filter)
:
:);
return filter;
}
int main() {
printf("%#x", func());
return 0;
}
---
Error message:
---
<source>:8:10: error: symbol '_filter' is already defined
"_filter:\n"
^
<inline asm>:3:1: note: instantiated into assembly here
_filter:
^
<source>:10:10: error: symbol '_out' is already defined
"_out:"
^
<inline asm>:5:1: note: instantiated into assembly here
_out:
^
2 errors generated.
ASM generation compiler returned: 1
<source>:8:10: error: symbol '_filter' is already defined
"_filter:\n"
^
<inline asm>:3:1: note: instantiated into assembly here
_filter:
^
<source>:10:10: error: symbol '_out' is already defined
"_out:"
^
<inline asm>:5:1: note: instantiated into assembly here
_out:
^
2 errors generated.
Execution build compiler returned: 1
---
It affects 11.0, 12.0, and trunk.
Trunk O0: <a href="https://godbolt.org/z/7afYjhGzc">https://godbolt.org/z/7afYjhGzc</a>
Trunk O2: <a href="https://godbolt.org/z/6K71Tde6s">https://godbolt.org/z/6K71Tde6s</a></pre>
</div>
</p>
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