[Bug target/79173] add-with-carry and subtract-with-borrow support (x86_64 and others)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79173

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |x86_64-*-*
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-01-23
            Version|unknown                     |7.0
     Ever confirmed|0                           |1
           Severity|normal                      |enhancement

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed, the bug should possibly be split (Clang compatible builtins, target
specific detection of patterns, middle-end detection of patterns).  Note a
suitable middle-end representation would not have the address argument but
likely
return two values (via the usual _Complex int trick).