clang crashes on valid code with __builtin_ia32_addcarryx_u64 on x86_64-linux-gnu

[zhendongsu]

Bugzilla Link	24943
Resolution	FIXED
Resolved on	Aug 14, 2017 17:09
Version	trunk
OS	All
Blocks	#33196
CC	@topperc,@deadalnix,@zmodem,@RKSimon,@sneves,@rotateright,@wjristow

Extended Description

The current clang trunk (as well as clang 3.6.x and 3.7.x) crashes when compiling the following code at all optimization levels in both 32-bit and 64-bit modes on x86_64-linux-gnu.

It is a regression from 3.5.x.

$ clang-trunk -v
clang version 3.8.0 (trunk 248604)
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-3.5 -c small.c
$
$ clang-trunk -c small.c
Value type is non-standard value, Other.
UNREACHABLE executed at /tmp/llvm/include/llvm/CodeGen/MachineValueType.h:387!
#​0 0x2fb75e8 llvm::sys::PrintStackTrace(llvm::raw_ostream&) (/usr/local/clang-trunk/bin/clang+0x2fb75e8)
#​1 0x2fb6386 llvm::sys::RunSignalHandlers() (/usr/local/clang-trunk/bin/clang+0x2fb6386)
#​2 0x2fb6596 (/usr/local/clang-trunk/bin/clang+0x2fb6596)
#​3 0x7f4be1849340 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x10340)
#​4 0x7f4be07e4cc9 gsignal /build/buildd/eglibc-2.19/signal/../nptl/sysdeps/unix/sysv/linux/raise.c:56:0
#​5 0x7f4be07e80d8 abort /build/buildd/eglibc-2.19/stdlib/abort.c:91:0
#​6 0x2f9b1ec (/usr/local/clang-trunk/bin/clang+0x2f9b1ec)
#​7 0x1a92ad8 (/usr/local/clang-trunk/bin/clang+0x1a92ad8)
#​8 0x252c250 llvm::SelectionDAG::getConstant(unsigned long, llvm::SDLoc, llvm::EVT, bool, bool) (/usr/local/clang-trunk/bin/clang+0x252c250)
#​9 0x23ce7cc llvm::X86TargetLowering::PerformDAGCombine(llvm::SDNode*, llvm::TargetLowering::DAGCombinerInfo&) const (/usr/local/clang-trunk/bin/clang+0x23ce7cc)
#​10 0x24c7aff (/usr/local/clang-trunk/bin/clang+0x24c7aff)
#​11 0x24c8263 (/usr/local/clang-trunk/bin/clang+0x24c8263)
#​12 0x24c9202 llvm::SelectionDAG::Combine(llvm::CombineLevel, llvm::AAResults&, llvm::CodeGenOpt::Level) (/usr/local/clang-trunk/bin/clang+0x24c9202)
#​13 0x2590ce7 llvm::SelectionDAGISel::CodeGenAndEmitDAG() (/usr/local/clang-trunk/bin/clang+0x2590ce7)
#​14 0x2599b9c llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) (/usr/local/clang-trunk/bin/clang+0x2599b9c)
#​15 0x259b889 llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) (/usr/local/clang-trunk/bin/clang+0x259b889)
#​16 0x2359c74 (/usr/local/clang-trunk/bin/clang+0x2359c74)
#​17 0x2f24e4f llvm::FPPassManager::runOnFunction(llvm::Function&) (/usr/local/clang-trunk/bin/clang+0x2f24e4f)
#​18 0x2f24e8b llvm::FPPassManager::runOnModule(llvm::Module&) (/usr/local/clang-trunk/bin/clang+0x2f24e8b)
#​19 0x2f26c37 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/usr/local/clang-trunk/bin/clang+0x2f26c37)
#​20 0xb8c5c8 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+0xb8c5c8)
#​21 0xb697ba (/usr/local/clang-trunk/bin/clang+0xb697ba)
#​22 0xdc3d02 clang::ParseAST(clang::Sema&, bool, bool) (/usr/local/clang-trunk/bin/clang+0xdc3d02)
#​23 0xb6bfa2 clang::CodeGenAction::ExecuteAction() (/usr/local/clang-trunk/bin/clang+0xb6bfa2)
#​24 0x960e76 clang::FrontendAction::Execute() (/usr/local/clang-trunk/bin/clang+0x960e76)
#​25 0x937f2e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/usr/local/clang-trunk/bin/clang+0x937f2e)
#​26 0x91978c clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/usr/local/clang-trunk/bin/clang+0x91978c)
#​27 0x911580 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/usr/local/clang-trunk/bin/clang+0x911580)
#​28 0x8f7dba main (/usr/local/clang-trunk/bin/clang+0x8f7dba)
#​29 0x7f4be07cfec5 __libc_start_main /build/buildd/eglibc-2.19/csu/libc-start.c:321:0
#​30 0x90fc0d _start (/usr/local/clang-trunk/bin/clang+0x90fc0d)
Stack dump:
0. Program arguments: /usr/local/clang-trunk/bin/clang -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -mrelax-all -disable-free -main-file-name small.c -mrelocation-model static -mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -target-linker-version 2.24 -dwarf-column-info -coverage-file /home/su/20150925-clang-build-test987/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 -fdebug-compilation-dir /home/su/20150925-clang-build-test987 -ferror-limit 19 -fmessage-length 100 -fobjc-runtime=gcc -fdiagnostics-show-option -fcolor-diagnostics -o small.o -x c small.c

1. 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 '@foo'
   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 248604)
   Target: x86_64-unknown-linux-gnu
   Thread model: posix
   InstalledDir: /usr/local/tools/bin
   clang: note: diagnostic msg: PLEASE submit a bug report to http://llvm.org/bugs/ 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-da852d.c
clang: note: diagnostic msg: /tmp/small-da852d.sh
clang: note: diagnostic msg:

---

$

---

typedef unsigned char u8;
typedef unsigned long long u64;

u8 __builtin_ia32_addcarryx_u64 (u8, u64, u64, u64 *);

void foo ()
{
__builtin_ia32_addcarryx_u64 (0, 0, 0, 0);
}

[wjristow]

FTR, we've come across the same crash on large test. (Reducing it resulted in
the equivalent test-case as "small.c", but with '__builtin_ia32_addcarry_u64()'
rather than '__builtin_ia32_addcarryx_u64()'.)

[zmodem]

deadalnix: Maybe related to #22945 ?

[deadalnix]

Aparently, I got some digging to do. The two looks related indeed.

[topperc]

This will be fixed by https://reviews.llvm.org/D36645

[topperc]

*** Bug llvm/llvm-bugzilla-archive#33229 has been marked as a duplicate of this bug. ***

[topperc]

*** Bug #22945 has been marked as a duplicate of this bug. ***

[topperc]

Fixed in r310784.

[topperc]

Hans, can we merge this to 5.0?

[zmodem]

Hans, can we merge this to 5.0?

Sounds good to me, but let's have it sit in trunk another day first.

[zmodem]

Hans, can we merge this to 5.0?

Sounds good to me, but let's have it sit in trunk another day first.

Merged in r310899.

[topperc]

mentioned in issue llvm/llvm-bugzilla-archive#33229

[zmodem]

mentioned in issue #33196