id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
9842	long long not lockfree on i686 compiled with clang	gjasny@…	timblechmann	"$ clang --version
Hello,

I just discovered that the lockfree test fails on trunk:
====== BEGIN OUTPUT ======
atomic<char> is always lock free
atomic<short> is always lock free
atomic<int> is always lock free
atomic<long> is always lock free
lockfree.cpp(29): test lock_free_macro_val == lock_free_expect failed in function: 'void verify_lock_free(const char *, int, int) [T = long long]'
atomic<long long> is never lock free
atomic<void *> is always lock free
atomic<bool> is always lock free

My system is a Mac with 10.9 and Xcode 5.1:
Apple LLVM version 5.1 (clang-503.0.38) (based on LLVM 3.4svn)
Target: x86_64-apple-darwin13.1.0
Thread model: posix

I build the three with:
b2 toolset=darwin architecture=x86 address-model=32

I think t boils down to the following:

$ clang -march=core2 -dM -E - -m32 < /dev/null|grep -i __GCC_ATOMIC_LLONG_LOCK_FREE
#define __GCC_ATOMIC_LLONG_LOCK_FREE 1

The lockfree test expects 2 here.

(Clang 3.4 on Linux also just returns 1 for long long).

If I change the code in the platform header and switch from gcc-atomic.hpp to gcc-x86.hpp the test passes.

Thanks,
Gregor"	Bugs	closed	To Be Determined	atomic	Boost Development Trunk	Problem	fixed		Andrey.Semashev@…