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| author | Saleem Abdulrasool <compnerd@compnerd.org> | 2017-08-23 16:50:27 +0000 |
|---|---|---|
| committer | Saleem Abdulrasool <compnerd@compnerd.org> | 2017-08-23 16:50:27 +0000 |
| commit | f8774f1d735253f54531b585915a7529837d70ce (patch) | |
| tree | a0ae3f9ad9191c9a0261a3e45c7493334e4b16e9 | |
| parent | 853a8d9ffcf76cbfeba132a932571e6cd07e1b79 (diff) | |
| download | bcm5719-llvm-f8774f1d735253f54531b585915a7529837d70ce.tar.gz bcm5719-llvm-f8774f1d735253f54531b585915a7529837d70ce.zip | |
ARM: explicitly specify the 8-byte alignment
It seems that GCC interprets `__attribute__((__aligned__))` as 8-byte
alignment on ARM, but clang does not. Explicitly specify the
double-word alignment value to ensure that the structure is properly
aligned.
llvm-svn: 311574
| -rw-r--r-- | libunwind/include/unwind.h | 2 | ||||
| -rw-r--r-- | libunwind/test/alignment.pass.cpp | 12 |
2 files changed, 11 insertions, 3 deletions
diff --git a/libunwind/include/unwind.h b/libunwind/include/unwind.h index a1a84e9e700..58dc3d95e8c 100644 --- a/libunwind/include/unwind.h +++ b/libunwind/include/unwind.h @@ -100,7 +100,7 @@ struct _Unwind_Control_Block { } pr_cache; long long int :0; /* Enforce the 8-byte alignment */ -} __attribute__((__aligned__)); +} __attribute__((__aligned__(8))); typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn) (_Unwind_State state, diff --git a/libunwind/test/alignment.pass.cpp b/libunwind/test/alignment.pass.cpp index 5ab55842621..1a3ca5a9230 100644 --- a/libunwind/test/alignment.pass.cpp +++ b/libunwind/test/alignment.pass.cpp @@ -13,8 +13,16 @@ #include <unwind.h> -struct MaxAligned {} __attribute__((aligned)); -static_assert(alignof(_Unwind_Exception) == alignof(MaxAligned), ""); +// EHABI : 8-byte aligned +// itanium: largest supported alignment for the system +#if defined(_LIBUNWIND_ARM_EHABI) +static_assert(alignof(_Unwind_Control_Block) == 8, + "_Unwind_Control_Block must be double-word aligned"); +#else +struct MaxAligned {} __attribute__((__aligned__)); +static_assert(alignof(_Unwind_Exception) == alignof(MaxAligned), + "_Unwind_Exception must be maximally aligned"); +#endif int main() { |
