[Bug middle-end/105533] UBSAN: gcc/expmed.cc:3272:26: runtime error: signed integer overflow: -9223372036854775808 - 1 cannot be represented in type 'long int'

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105533

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenth at gcc dot gnu.org

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
The second UB is on
#2  ao_ref_init_from_vn_reference (ref=<optimized out>, set=1, base_set=1,
type=<optimized out>, ops=...) at ../../gcc/tree-ssa-sccvn.cc:1224
1224                offset += op->off << LOG2_BITS_PER_UNIT;
where op->off is negative.
Isn't this just an unnecessary optimization?  I mean can't we just do
                    offset += op->off * BITS_PER_UNIT;
BITS_PER_UNIT is a constant 8 on all targets we support...