[Bug tree-optimization/87314] pointless comparison of malloc result to a string not eliminated

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87314

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-09-17
                 CC|                            |rguenth at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
The issue is in ptrs_compare_unequal () which is limited because points-to
analysis doesn't conservatively propagate NULL and also because it doesn't
handle STRING_CST (similar reason, we drop all pointed-to-readonly-string).