| d3ca9828e34240334763f5153b925060b29b26e4 |
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01-Aug-2016 |
JF Bastien <jfb@google.com> |
atomics.align: XFAIL GCC
It currently fails because GCC changed the mangling of templates, which affects std::atomic using __attribute__((vector(X))). The bot using GCC 4.9 generates the following message:
In file included from /home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/test/libcxx/atomics/atomics.align/align.pass.sh.cpp:24:0:
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic: In instantiation of 'atomic_test<T>::atomic_test() [with T = __vector(2) int]':
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/test/libcxx/atomics/atomics.align/align.pass.sh.cpp:66:3: required from here
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: error: 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(2) int]' conflicts with a previous declaration
__gcc_atomic_t() _NOEXCEPT = default;
^
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: note: previous declaration 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(1) int]'
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: note: -fabi-version=6 (or =0) avoids this error with a change in mangling
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: error: 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(2) int]' conflicts with a previous declaration
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: note: previous declaration 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(1) int]'
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: note: -fabi-version=6 (or =0) avoids this error with a change in mangling
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:939:5: note: synthesized method 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(2) int]' first required here
__atomic_base() _NOEXCEPT = default;
^
GCC's docs say the following about ABI version 6:
Version 6, which first appeared in G++ 4.7, corrects the promotion behavior of C++11 scoped enums and the mangling of template argument packs, const/static_cast, prefix ++ and –, and a class scope function used as a template argument.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@277380 91177308-0d34-0410-b5e6-96231b3b80d8
/external/libcxx/test/libcxx/atomics/atomics.align/align.pass.sh.cpp
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| d836c0e3cbf265d0509ea4f53fb42eb603f090b6 |
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01-Aug-2016 |
JF Bastien <jfb@google.com> |
libc++: test lock-free atomic alignment
Summary:
libc++ implements std::atomic<_Tp> using __atomic_base<_Tp> with
`mutable _Atomic(_Tp) __a_`. That member must be suitably aligned on
relevant ISAs for instructions such as cmpxchg to work properly, but
this alignment isn't checked anywhere. __atomic_base's implementation
relies on _Atomic doing "the right thing" since it's under the
compiler's control, and only the compiler knows about lock-freedom and
instruction generation. This test makes sure that the compiler isn't
breaking libc++'s expectations.
I'm looking at a few odd things in the C++ standard, and will have a few
other fixes around this area in the future.
This requires building with `-DLIBCXX_HAS_ATOMIC_LIB=True`, the test
marks the dependency as REQUIRES and won't be run without.
Reviewers: cfe-commits
Subscribers: EricWF, mclow.lists
Differential Revision: http://reviews.llvm.org/D22073
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@277368 91177308-0d34-0410-b5e6-96231b3b80d8
/external/libcxx/test/libcxx/atomics/atomics.align/align.pass.sh.cpp
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