[Bug c/79731] [7 Regression] ICE: verify_gimple failed

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79731

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Ugh, the BIT_FIELD_REF is built by fold_truth_andor...  (elsewhere we avoid
creating those).  We fold

(BIT_FIELD_REF <x, 64, 0> & 18446744073709551615) != 0 ||
VIEW_CONVERT_EXPR<unsigned int[2]>(x)[2] != 0

Probably best avoided in decode_field_reference by returning NULL_TREE for
out-of-bound accesses.