[Bug middle-end/87220] -fstack-check produces inefficient and wrong tests

[amonakov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87220

--- Comment #8 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
(In reply to Eric Botcazou from comment #7)
> We cannot reasonably document that a feature does exactly the opposite of
> what it is intended to do, can we?  You need to compile the entire software
> with the
> option, that's all.

Okay, so can you please document that -fstack-check probes one extra page ahead
by design, skipping one page adjacent to current stack pointer on the
assumption that callers are also compiled with -fstack-check and therefore must
have probed that page previously?

I think an indication that this option is intended for use with Ada also would
help.