[Bug target/88234] UBsan and runtime error: signed integer overflow using unsigned vector

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88234

Segher Boessenkool <segher at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-11-28
     Ever confirmed|0                           |1

--- Comment #4 from Segher Boessenkool <segher at gcc dot gnu.org> ---
This is documented in the ELFv2 ABI, linked from
https://gcc.gnu.org/readings.html .

vec_add is overloaded, and defined as  X vec_add(X, X)  for pretty much every
vector type X.  So I would expect everything to be vector unsigned int here,
but something is going wrong.

Confirmed.

(The vec_vsx_st doesn't have to do with the problem btw.  Not that it is
good or anything ;-) )