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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 --- - clang crashes on valid code at -O3 on x86_64-linux-gnu"
href="http://llvm.org/bugs/show_bug.cgi?id=18688">18688</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>clang crashes on valid code at -O3 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 current clang trunk crashes when compiling the following testcase at -O3 in
both 32-bit and 64-bit modes on x86_64-linux-gnu.
This is a regression from clang 3.4.
$ clang-trunk -v
clang version 3.5 (trunk 200521)
Target: x86_64-unknown-linux-gnu
Thread model: posix
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
$
$ clang-trunk -O2 -c small.c
$ clang-3.4 -O3 -c small.c
$
$ clang-trunk -O3 -c small.c
clang: /tmp/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp:394: virtual bool
<anonymous namespace>::LoopUnswitch::runOnLoop(llvm::Loop *,
llvm::LPPassManager &): Assertion `currentLoop->isLCSSAForm(*DT)' failed.
0 clang 0x0000000002362165 llvm::sys::PrintStackTrace(_IO_FILE*) +
37
1 clang 0x0000000002362953
2 libpthread.so.0 0x00007fdabd22ccb0
3 libc.so.6 0x00007fdabc04a425 gsignal + 53
4 libc.so.6 0x00007fdabc04db8b abort + 379
5 libc.so.6 0x00007fdabc0430ee
6 libc.so.6 0x00007fdabc043192
7 clang 0x0000000001f6098b
8 clang 0x000000000212c310
llvm::LPPassManager::runOnFunction(llvm::Function&) + 944
9 clang 0x0000000002277184
llvm::FPPassManager::runOnFunction(llvm::Function&) + 356
10 clang 0x00000000020a13c5
11 clang 0x00000000022779a7
llvm::legacy::PassManagerImpl::run(llvm::Module&) + 999
12 clang 0x0000000000872413
clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::CodeGenOptions
const&, clang::TargetOptions const&, clang::LangOptions const&,
llvm::StringRef, llvm::Module*, clang::BackendAction, llvm::raw_ostream*) +
6579
13 clang 0x000000000086fd99
14 clang 0x00000000009fc5e3 clang::ParseAST(clang::Sema&, bool, bool)
+ 515
15 clang 0x000000000086ebbe clang::CodeGenAction::ExecuteAction() +
142
16 clang 0x00000000006ce3d0 clang::FrontendAction::Execute() + 112
17 clang 0x00000000006aad8d
clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) + 925
18 clang 0x0000000000691410
clang::ExecuteCompilerInvocation(clang::CompilerInstance*) + 2896
19 clang 0x0000000000688fe4 cc1_main(char const**, char const**, char
const*, void*) + 692
20 clang 0x000000000068dba7 main + 3431
21 libc.so.6 0x00007fdabc03576d __libc_start_main + 237
22 clang 0x0000000000688c49
Stack dump:
0. Program arguments: /usr/local/clang-trunk/bin/clang -cc1 -triple
x86_64-unknown-linux-gnu -emit-obj -disable-free -main-file-name small.c
-mrelocation-model static -fmath-errno -masm-verbose -mconstructor-aliases
-munwind-tables -fuse-init-array -target-cpu x86-64 -target-linker-version 2.22
-momit-leaf-frame-pointer -coverage-file
/data2/c-hunter-results/C/trans-bugs/REPORTED/20131210-clang-m32-m64-O3-wrong-test308654/run-crash/small.o
-resource-dir /usr/local/clang-trunk/bin/../lib/clang/3.5 -internal-isystem
/usr/local/include -internal-isystem
/usr/local/clang-trunk/bin/../lib/clang/3.5/include -internal-externc-isystem
/usr/include/x86_64-linux-gnu -internal-externc-isystem /include
-internal-externc-isystem /usr/include -O3 -fdebug-compilation-dir
/data2/c-hunter-results/C/trans-bugs/REPORTED/20131210-clang-m32-m64-O3-wrong-test308654/run-crash
-ferror-limit 19 -fmessage-length 122 -mstackrealign -fobjc-runtime=gcc
-fdiagnostics-show-option -fcolor-diagnostics -vectorize-loops -vectorize-slp
-o small.o -x c small.c
1. <eof> parser at end of file
2. Per-module optimization passes
3. Running pass 'CallGraph Pass Manager' on module 'small.c'.
4. Running pass 'Loop Pass Manager' on function '@foo'
5. Running pass 'Unswitch loops' on basic block '%for.body3.us11'
clang: error: unable to execute command: Aborted (core dumped)
clang: error: clang frontend command failed due to signal (use -v to see
invocation)
clang version 3.5 (trunk 200521)
Target: x86_64-unknown-linux-gnu
Thread model: posix
clang: note: diagnostic msg: PLEASE submit a bug report to
<a href="http://llvm.org/bugs/">http://llvm.org/bugs/</a> and include the crash backtrace, preprocessed source, and
associated run script.
clang: note: diagnostic msg:
********************
PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /tmp/small-347c1a.c
clang: note: diagnostic msg: /tmp/small-347c1a.sh
clang: note: diagnostic msg:
********************
$
----------------------------
int a, b, c, d;
void
foo ()
{
for (; a;)
{
b = 0;
for (; c;)
d || (b = 0);
}
}</pre>
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