[Bug c++/82505] g++ -O3 -funroll-loops generates weird code

[amonakov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82505

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |amonakov at gcc dot gnu.org
         Resolution|---                         |INVALID

--- Comment #4 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
t2 needs more code simply because it does more work: in C you can read
representations of objects byte-by-byte via 'char *' pointers. Consider what
happens if src is initialized like 'src = (void *)&src;' prior to invoking t2
(then the loop in t2 modifies src on each iteration, and also reads a byte of
its representation).