[Bug rtl-optimization/99680] [11 Regression] AddressSanitizer: global-buffer-overflow since g:04b4828c6dd2

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99680

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I was worried that letters that introduce multi-letter constraints followed by
'\0' could be a problem too.  Or do we rely on those being dropped already
earlier?
Something like "=B" on x86_64 etc.  In what I've tried it was dropped during
vregs pass though.
And when cn already is CONSTRAINT__UNKNOWN, performing checks whether to set it
to CONSTRAINT__UNKNOWN is just wasted time.