[Bug tree-optimization/82494] UBSAN in gcc/tree-data-ref.c:3427:16: runtime error: signed integer overflow: 131072 * -131072 cannot be represented in type 'int'

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82494

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-10-09
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I think there's a dup somewhere.  We've discussed that

typedef int *lambda_vector;

is simply too optimistic.  The machinery assumes this is an arbitrary precision
integer ;)  A optimistic "fix" would be to make it int64_t, probably catching
most (if not all) practical cases (all overflows are possibly wrong-code!).

A real fix would involve either using gmp (ugh) or making a lot of routines
failable that are not right now plus using overflow-detecting math (and fail).