Hi Richard,

> I think it would be better to fold this into the existing documentation
> a bit more:
[..]

done.

Fixed the remaining nits in the attached v5.

Bootstrap and regtest are good on s390x, Power9 and i386.

Regards
 Robin

--

gcc/ChangeLog:

        * config/rs6000/vsx.md: Use const0 bias predicate.
        * doc/md.texi: Document bias value.
        * internal-fn.c (expand_partial_load_optab_fn): Add bias.
        (expand_partial_store_optab_fn): Likewise.
        (internal_len_load_store_bias): New function.
        * internal-fn.h (VECT_PARTIAL_BIAS_UNSUPPORTED): New define.
        (internal_len_load_store_bias): New function.
        * tree-vect-loop-manip.c (vect_set_loop_controls_directly): Set
bias.
        (vect_set_loop_condition_partial_vectors): Add header_seq parameter.
        * tree-vect-loop.c (vect_verify_loop_lens): Verify bias.
        (vect_estimate_min_profitable_iters): Account for bias.
        (vect_get_loop_len): Add bias-adjusted length.
        * tree-vect-stmts.c (vectorizable_store): Use.
        (vectorizable_load): Use.
        * tree-vectorizer.h (struct rgroup_controls): Add bias-adjusted
length.
        (LOOP_VINFO_PARTIAL_LOAD_STORE_BIAS): New macro.