compnerd added inline comments. ================ Comment at: lib/Headers/intrin.h:504 @@ +503,3 @@ +_interlockedbittestandset_acq(long volatile *_BitBase, long _BitPos) { + long _PrevVal = __atomic_fetch_or(_BitBase, 1l << _BitPos, __ATOMIC_ACQUIRE); + return (_PrevVal >> _BitPos) & 1; ---------------- mstorsjo wrote: > compnerd wrote: > > Perhaps we should add static asserts that _BitPos is within limits for the > > signed shift. > Sure, although I guess that also goes for the existing inline functions as > well? > > Which kind of assert would be suitable for that here? As far as I see, > static_assert is C++ only, while this header also can be used from C. > > If I try to add _Static_assert, which is usable in C, I get the following > error when compiling: > > intrin.h:499:18: error: > static_assert expression is not an integral constant expression > _Static_assert(_BitPos < 32, "_BitPos out of range"); > > This even when I don't actually use the inline function anywhere, just > including intrin.h. Yeah, we would have to use `_Static_assert`, but that requires C11. It is possible to emulate it, but probably not worth the effort. I am worried though that we could introduce undefined behavior with an incorrect parameter.
https://reviews.llvm.org/D24609 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits