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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - addrspec causes incorrect load/store with optimization on"
href="http://llvm.org/bugs/show_bug.cgi?id=18032">18032</a>
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<th>Summary</th>
<td>addrspec causes incorrect load/store with optimization on
</td>
</tr>
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<th>Product</th>
<td>libraries
</td>
</tr>
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<th>Version</th>
<td>3.3
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
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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>
</tr>
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<th>Component</th>
<td>Backend: X86
</td>
</tr>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>tobias.haegermarck@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>To illustrate:
#include<stdio.h>
struct a { int foo; char *bar; };
struct b { a *foo; };
int main() { printf("%s", ((b
__attribute__((address_space(256)))*)0)->foo->bar); }
Compile with:
clang++ -O3 -c -emit-llvm -o - addrspec.cpp | llc -O1 -o - -
This generates the following instruction:
movq %gs:8, %rsi
Which loads from outside of the 'b' structure (seems to assume that a is
located at %gs:0, which is incorrect).
If -O0 is instead passed to llc, the result is as expected (load 'foo' from b,
load 'bar' from a)</pre>
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