[Bug c++/82663] optimizer duplicates assembly jump label (when -std=c++11 and -O3)

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82663

Segher Boessenkool <segher at gcc dot gnu.org> changed:

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

--- Comment #1 from Segher Boessenkool <segher at gcc dot gnu.org> ---
That's not valid code.  See the last paragraph of
https://gcc.gnu.org/onlinedocs/gcc-7.2.0/gcc/Extended-Asm.html#Volatile :

Under certain circumstances, GCC may duplicate (or remove duplicates of)
your assembly code when optimizing. This can lead to unexpected duplicate
symbol errors during compilation if your asm code defines symbols or labels.
Using ‘%=’ (see AssemblerTemplate) may help resolve this problem.