https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84747
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jakub at gcc dot gnu.org
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
On some targets where the address spaces are really separate, one kind of
memory and another kind of memory, I can see why assuming non-aliasing is fine.
But exactly on x86_64 I don't see how that could be safe, %fs/%gs simply are
the given addresses plus the segment base. You can access the same memory both
with
%gs:ptr1 and ptr2 where ptr2 is ptr1 + gs_segment_base, e.g. glibc uses for TLS
heavily both kinds of accesses.
