https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108968
--- Comment #12 from David Malcolm <dmalcolm at gcc dot gnu.org> --- (In reply to Andrew Cooper from comment #9) [...snip...] > Our code does fundamentally rely on get_cpu_info() always returning the same > pointer (on a single CPU). For example, `current` is defined as > `get_cpu_info()->current` and we do expect that to yield the same pointer > when used multiple times. > > Even if the analyser was interpreting the generated asm, there's no way it > could prove this without knowing the size/alignment constraints of our > stacks. Another issue is that even if the analyzer "knows" that get_cpu_info() always returns the same value, it doesn't know what memory is being pointed to, and so has to assume that in: T old_value = get_cpu_info()->current; some_function_call (); T new_value = get_cpu_info()->current; that old_value doesn't necessarily equal new_value, since some_function_call () could have modified the value of "current".
