[Bug tree-optimization/122297] Wrong code due to bad VEC_EXTRACT index when LEN_LOAD falls back to QI mode

[jchrist at linux dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122297

--- Comment #8 from jchrist at linux dot ibm.com ---
(In reply to Richard Biener from comment #5)
> Hum.  Can you point me to where we fall back to byte-based len?

I don't know where this happens, but if I check the generated gimple, I see
that we use byte sizes for loads/stores, but if none are present (as in
nodump-vecextract-1.c), we use element sizes.  This can also be seen (and I
assume you found the same thing) with the different factors passed to
vect_record_loop_len.  I was surprised to see that this factor is stored, but
in the case of a load bias completely ignored.