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<head>
<base href="http://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 - opt crashes with "opt -instcombine -newgvn": Assertion `BeforeCC->isEquivalentTo(AfterCC) && "Value number changed after main loop completed!"' failed"
href="http://bugs.llvm.org/show_bug.cgi?id=32836">32836</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>opt crashes with "opt -instcombine -newgvn": Assertion `BeforeCC->isEquivalentTo(AfterCC) && "Value number changed after main loop completed!"' failed
</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>enhancement
</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>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>$ clang -v
clang version 5.0.0 (trunk 301511) (llvm/trunk 301510)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/clang-trunk/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.9.4
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5.3.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4.7
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/4.8.5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.3.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.2.0
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64
$
$ clang -w -c -emit-llvm -o small.bc small.c
$ opt -instcombine -newgvn -o small-opt.bc small.bc
opt: /tmp/llvm-builder/llvm-source-trunk/lib/Transforms/Scalar/NewGVN.cpp:2613:
void {anonymous}::NewGVN::verifyIterationSettled(llvm::Function&): Assertion
`BeforeCC->isEquivalentTo(AfterCC) && "Value number changed after main loop
completed!"' failed.
#0 0x0000000001e54b9a (opt+0x1e54b9a)
#1 0x0000000001e52cbe (opt+0x1e52cbe)
#2 0x0000000001e52e20 (opt+0x1e52e20)
#3 0x00007f6e7df0a330 __restore_rt
(/lib/x86_64-linux-gnu/libpthread.so.0+0x10330)
#4 0x00007f6e7ccf3c37 gsignal
/build/eglibc-MjiXCM/eglibc-2.19/signal/../nptl/sysdeps/unix/sysv/linux/raise.c:56:0
#5 0x00007f6e7ccf7028 abort
/build/eglibc-MjiXCM/eglibc-2.19/stdlib/abort.c:91:0
#6 0x00007f6e7ccecbf6 __assert_fail_base
/build/eglibc-MjiXCM/eglibc-2.19/assert/assert.c:92:0
#7 0x00007f6e7ccecca2 (/lib/x86_64-linux-gnu/libc.so.6+0x2fca2)
#8 0x0000000001d3e81b (opt+0x1d3e81b)
#9 0x0000000001d3f987 (opt+0x1d3f987)
#10 0x00000000019a3a23 (opt+0x19a3a23)
#11 0x00000000019a3acc (opt+0x19a3acc)
#12 0x00000000019a430a (opt+0x19a430a)
#13 0x0000000000840307 (opt+0x840307)
#14 0x00007f6e7ccdef45 __libc_start_main
/build/eglibc-MjiXCM/eglibc-2.19/csu/libc-start.c:321:0
#15 0x000000000089b709 (opt+0x89b709)
Stack dump:
0. Program arguments: opt -instcombine -newgvn -o small-opt.bc small.bc
1. Running pass 'Function Pass Manager' on module 'small.bc'.
2. Running pass 'Global Value Numbering' on function '@fn1'
Aborted (core dumped)
$
-------------------------
struct
{
int a:29;
} b;
int c, d, e, f, g;
short h;
void fn1 ()
{
int j = 8;
if (e)
{
j = b.a;
L:;
}
b.a = j;
f || g;
short l = c | b.a;
l || 0;
if (d)
goto L;
h = l;
}
int main ()
{
fn1 ();
return 0;
}</pre>
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