[Bug target/85961] scratch register rsi used after function call

[amonakov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85961

Alexander Monakov <amonakov at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amonakov at gcc dot gnu.org

--- Comment #3 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
You'd need to disable IPA-RA after forcing -O2 with the pragma, i.e.:

#pragma GCC optimize "O2"
#pragma GCC optimize "no-ipa-ra"

We already have logic to disable IPA-RA when instrumentation/profiling is
active, but it's done once in toplev.c. Here the pragma re-enables IPA-RA after
toplev.c:process_options() has disabled it.

Do we want to adjust it given that "pragma optimized" is documented as "not
suitable for production use"?