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<base href="https://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 at -O1 and above on x86_64-linux-gnu"
href="https://llvm.org/bugs/show_bug.cgi?id=24617">24617</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>clang crashes at -O1 and above 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>llvm-bugs@lists.llvm.org
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>The current clang trunk crashes when compiling the following test case on
x86_64-linux-gnu at -O1 and above in both 32-bit and 64-bit modes.
This is a regression from 3.6.x.
$ clang-trunk -v
clang version 3.8.0 (trunk 246189)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/tools/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.9.2
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5.1.0
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/4.8.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.1.0
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-trunk -O0 -c small.c
small.c:12:15: warning: unsequenced modification and access to 'h'
[-Wunsequenced]
h += (h *= c);
~~ ^
1 warning generated.
$ clang-3.6 -O1 -c small.c
small.c:12:15: warning: unsequenced modification and access to 'h'
[-Wunsequenced]
h += (h *= c);
~~ ^
1 warning generated.
$
$ clang-trunk -O1 -c small.c
small.c:12:15: warning: unsequenced modification and access to 'h'
[-Wunsequenced]
h += (h *= c);
~~ ^
clang: /tmp/llvm/include/llvm/Support/Casting.h:81: static bool
llvm::isa_impl_cl<llvm::ConstantSDNode, llvm::SDNode *>::doit(const From *) [To
= llvm::ConstantSDNode, From = llvm::SDNode *]: Assertion `Val && "isa<> used
on a null pointer"' failed.
#0 0x2bdecad llvm::sys::PrintStackTrace(llvm::raw_ostream&)
(/usr/local/clang-trunk/bin/clang+0x2bdecad)
#1 0x2bde336 llvm::sys::RunSignalHandlers()
(/usr/local/clang-trunk/bin/clang+0x2bde336)
#2 0x2be014a (/usr/local/clang-trunk/bin/clang+0x2be014a)
#3 0x7fc9ffe43340 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x10340)
#4 0x7fc9feddecc9 gsignal
/build/buildd/eglibc-2.19/signal/../nptl/sysdeps/unix/sysv/linux/raise.c:56:0
#5 0x7fc9fede20d8 abort /build/buildd/eglibc-2.19/stdlib/abort.c:91:0
#6 0x7fc9fedd7b86 __assert_fail_base
/build/buildd/eglibc-2.19/assert/assert.c:92:0
#7 0x7fc9fedd7c32 (/lib/x86_64-linux-gnu/libc.so.6+0x2fc32)
#8 0x21f66c7 llvm::SelectionDAG::getNode(unsigned int, llvm::SDLoc, llvm::EVT,
llvm::SDValue, llvm::SDValue, llvm::SDNodeFlags const*)
(/usr/local/clang-trunk/bin/clang+0x21f66c7)
#9 0x2183e51 (/usr/local/clang-trunk/bin/clang+0x2183e51)
#10 0x215474c (/usr/local/clang-trunk/bin/clang+0x215474c)
#11 0x21535cd llvm::SelectionDAG::Combine(llvm::CombineLevel,
llvm::AliasAnalysis&, llvm::CodeGenOpt::Level)
(/usr/local/clang-trunk/bin/clang+0x21535cd)
#12 0x226f794 llvm::SelectionDAGISel::CodeGenAndEmitDAG()
(/usr/local/clang-trunk/bin/clang+0x226f794)
#13 0x226ec01 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function
const&) (/usr/local/clang-trunk/bin/clang+0x226ec01)
#14 0x226be3f
llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&)
(/usr/local/clang-trunk/bin/clang+0x226be3f)
#15 0x20616c1 (/usr/local/clang-trunk/bin/clang+0x20616c1)
#16 0x240452c llvm::MachineFunctionPass::runOnFunction(llvm::Function&)
(/usr/local/clang-trunk/bin/clang+0x240452c)
#17 0x2b3d9c4 llvm::FPPassManager::runOnFunction(llvm::Function&)
(/usr/local/clang-trunk/bin/clang+0x2b3d9c4)
#18 0x2b3dc0b llvm::FPPassManager::runOnModule(llvm::Module&)
(/usr/local/clang-trunk/bin/clang+0x2b3dc0b)
#19 0x2b3e0e5 llvm::legacy::PassManagerImpl::run(llvm::Module&)
(/usr/local/clang-trunk/bin/clang+0x2b3e0e5)
#20 0x985bdd clang::EmitBackendOutput(clang::DiagnosticsEngine&,
clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions
const&, llvm::StringRef, llvm::Module*, clang::BackendAction,
llvm::raw_pwrite_stream*) (/usr/local/clang-trunk/bin/clang+0x985bdd)
#21 0x976c55 (/usr/local/clang-trunk/bin/clang+0x976c55)
#22 0xb92d76 clang::ParseAST(clang::Sema&, bool, bool)
(/usr/local/clang-trunk/bin/clang+0xb92d76)
#23 0x76f5a5 clang::FrontendAction::Execute()
(/usr/local/clang-trunk/bin/clang+0x76f5a5)
#24 0x73e07c clang::CompilerInstance::ExecuteAction(clang::FrontendAction&)
(/usr/local/clang-trunk/bin/clang+0x73e07c)
#25 0x71f8e7 clang::ExecuteCompilerInvocation(clang::CompilerInstance*)
(/usr/local/clang-trunk/bin/clang+0x71f8e7)
#26 0x715cb5 cc1_main(llvm::ArrayRef<char const*>, char const*, void*)
(/usr/local/clang-trunk/bin/clang+0x715cb5)
#27 0x71e01c main (/usr/local/clang-trunk/bin/clang+0x71e01c)
#28 0x7fc9fedc9ec5 __libc_start_main
/build/buildd/eglibc-2.19/csu/libc-start.c:321:0
#29 0x715741 _start (/usr/local/clang-trunk/bin/clang+0x715741)
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 -mthread-model posix -fmath-errno -masm-verbose
-mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64
-target-linker-version 2.24 -momit-leaf-frame-pointer -dwarf-column-info
-coverage-file /data2/20150828-clang-m32-m64-O1-Os-O2-O3-build/small.c
-resource-dir /usr/local/clang-trunk/bin/../lib/clang/3.8.0 -internal-isystem
/usr/local/include -internal-isystem
/usr/local/clang-trunk/bin/../lib/clang/3.8.0/include -internal-externc-isystem
/usr/include/x86_64-linux-gnu -internal-externc-isystem /include
-internal-externc-isystem /usr/include -O1 -fdebug-compilation-dir
/data2/20150828-clang-m32-m64-O1-Os-O2-O3-build -ferror-limit 19
-fmessage-length 121 -mstackrealign -fobjc-runtime=gcc
-fdiagnostics-show-option -fcolor-diagnostics -o small.o -x c small.c
1. <eof> parser at end of file
2. Code generation
3. Running pass 'Function Pass Manager' on module 'small.c'.
4. Running pass 'X86 DAG->DAG Instruction Selection' on function '@fn1'
clang: error: unable to execute command: Aborted
clang: error: clang frontend command failed due to signal (use -v to see
invocation)
clang version 3.8.0 (trunk 246189)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/tools/bin
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-30e84a.c
clang: note: diagnostic msg: /tmp/small-30e84a.sh
clang: note: diagnostic msg:
********************
$
----------------------------------
int a, b;
long long c;
void
fn1 ()
{
if (b)
{
a = 1;
c /= 3000000000;
unsigned h = 3000000000;
h += (h *= c);
b = h;
if (h)
b = a;
}
}</pre>
</div>
</p>
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