[Bug rtl-optimization/64294] invalid code, zero check gets optimized away

[schwab@linux-m68k.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64294

Andreas Schwab <schwab@linux-m68k.org> changed:

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

--- Comment #1 from Andreas Schwab <schwab@linux-m68k.org> ---
This condition is true if backsize == 0:
     if(!((bufsz) > 0 && (backsize) > 0 && (size_t)(backsize) <=
(size_t)(bufsz) && (ddst) >= (buf) && ((ddst) + (backsize)) <= ((buf) +
(bufsz)) && ((ddst) + (backsize)) > (buf) && (ddst) < ((buf) + (bufsz))) ||
!((bufsz) > 0 && (backsize) > 0 && (size_t)(backsize) <= (size_t)(bufsz) &&
(ddst+backbytes) >= (buf) && ((ddst+backbytes) + (backsize)) <= ((buf) +
(bufsz)) && ((ddst+backbytes) + (backsize)) > (buf) && (ddst+backbytes) <
((buf) + (bufsz)))) {