http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55975
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-01-16 11:50:47 UTC --- I think for 44->46 bits we can still make it constant. But generally, the constructors of libasan are usually run from the stack of the initial thread, so it should be enough to look at address of any local variable and check if it is around (1 << 44) - epsilon or (1 << 46) - epsilon.
