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<base href="https://bugs.llvm.org/">
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<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Function merging pass miscompiles identical vararg functions"
href="https://bugs.llvm.org/show_bug.cgi?id=40345">40345</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Function merging pass miscompiles identical vararg functions
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<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>Interprocedural Optimizations
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>vsk@apple.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>Example:
```
#include <stdarg.h>
void escape(int);
void simple_va(const char* fmt, ...)
{
va_list args;
va_start(args, fmt);
int i = va_arg(args, int);
escape(i);
va_end(args);
}
void simple_va2(const char* fmt, ...)
{
va_list args;
va_start(args, fmt);
int i = va_arg(args, int);
escape(i);
va_end(args);
}
```
Clang emits (<a href="https://godbolt.org/z/C54W53">https://godbolt.org/z/C54W53</a>):
```
; Function Attrs: minsize optsize uwtable
define dso_local void @_Z9simple_vaPKcz(i8* nocapture readnone, ...)
local_unnamed_addr #3 {
tail call void (i8*, ...) @_Z10simple_va2PKcz(i8* nocapture readnone %0) #3
ret void
}
```</pre>
</div>
</p>
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