https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108017
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
Last reconfirmed| |2022-12-08
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
We do this for &x + C {!=,==} &x' + C' - I think we're afraid of relational
compares here though, even with TYPE_OVERFLOW_UNDEFINED.
/* (&a+b) !=/== (&a[1] + c) -> sizeof(a[0]) + b !=/== c */
(for neeq (ne eq)
(simplify
(neeq (pointer_plus ADDR_EXPR@0 @1) (pointer_plus ADDR_EXPR@2 @3))
(with { poly_int64 diff; tree inner_type = TREE_TYPE (@1);}
(if (ptr_difference_const (@0, @2, &diff))
(neeq (plus { build_int_cst_type (inner_type, diff); } @1) @3)))))
that could be relaxed to general @0/@2 (at some cost) and to
relational compares with TYPE_OVERFLOW_UNDEFINED.
