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<base href="http://llvm.org/bugs/" />
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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 --- - LTO crashes with linker error on invalid code at -O1 on x86_64-linux-gnu"
href="http://llvm.org/bugs/show_bug.cgi?id=19184">19184</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>LTO crashes with linker error on invalid code at -O1 on x86_64-linux-gnu
</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>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>-New Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>su@cs.ucdavis.edu
</td>
</tr>
<tr>
<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>The following (invalid) code causes a linker error when it is compiled on
x86_64-linux-gnu by the current clang trunk using LTO at -O1 in both 32-bit and
64-bit modes.
This is a regression from clang 3.4
Perhaps related to 19079, but it only triggers in 64-bit mode.
$ clang-trunk -v
clang version 3.5.0 (trunk 204149)
Target: x86_64-unknown-linux-gnu
Thread model: posix
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.8
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.8.1
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4.6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7.3
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8.1
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
$
$ clang-trunk -O1 small.c
$ clang-3.4 -flto -O1 small.c
$ clang-trunk -flto -O0 small.c
$
$ clang-trunk -flto -O1 small.c
ld: /tmp/llvm/include/llvm/Support/Casting.h:237: typename cast_retty<X, Y
*>::ret_type llvm::cast(Y *) [X = llvm::PHINode, Y = llvm::Instruction]:
Assertion `isa<X>(Val) && "cast<Ty>() argument of incompatible type!"' failed.
clang: error: unable to execute command: Aborted (core dumped)
clang: error: linker command failed due to signal (use -v to see invocation)
$
------------------------------
int a, e;
struct
{
int f1;
volatile int f2;
int f3;
} b, c;
int d[1];
int
fn1 (int p)
{
return p;
}
int
fn2 (int p)
{
return p ? p : a % p;
}
void fn3 ();
void
fn4 ()
{
fn3 (d);
}
void
fn3 (int p)
{
int j, f;
if (fn1 (p))
p = 1;
for (; c.f1; c.f1++)
{
if (p)
f = e > 0;
e |= 1;
if (p > 1)
for (; j; j++)
b.f3 = fn2 (f);
b.f2;
}
}
int
main ()
{
fn4 ();
return 0;
}</pre>
</div>
</p>
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