[Bug rtl-optimization/120284] inline assembly operand constraint not comply with document

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120284

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
asm volatile("" : "+r"(x)); 

is the same as:
    asm volatile("" : "=r"(x) : "0"(x)); 


Note the 0 there rather than r. r in the input means any register while 0 means
it needs to match the same register as the 0th operand which in this case is
the output operand.