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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 --- - miscompilation on i386 with -fPIC (recent regression)"
href="http://llvm.org/bugs/show_bug.cgi?id=18029">18029</a>
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<th>Summary</th>
<td>miscompilation on i386 with -fPIC (recent regression)
</td>
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<th>Product</th>
<td>new-bugs
</td>
</tr>
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Linux
</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>new bugs
</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>kcc@google.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>r195419 on x86 linux:
% cat b.cc
#include <stdio.h>
int Bar(int *a) {
return *a;
}
int Foo(int *a) {
return Bar(a);
}
int main() {
int a[7] = {0, 1, 2, 3, 4, 5, 6};
printf("result: %d (should be 3)\n", Foo(&a[3]));
}
% clang -m32 -O1 b.cc; ./a.out
result: 3 (should be 3)
% clang -O1 b.cc; ./a.out
result: 3 (should be 3)
% clang -m32 -O1 b.cc -fPIC ; ./a.out
result: 69485705 (should be 3)
%
The code looks like this:
08048400 <_Z3FooPi>:
8048400: e8 eb ff ff ff call 80483f0 <_Z3BarPi>
8048405: c3 ret
This is obviously wrong, you can not call a function with a parameter like
this on i386, where the parameters are passed via stack.
This is a very recent regression.</pre>
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