PR rtl-optimization/59461
* doc/rtl.texi (paradoxical subregs): Add missing word.
* combine.c (reg_nonzero_bits_for_combine): Do not discard results
in modes with precision larger than that of last_set_mode.
* rtlanal.c (nonzero_bits1) <SUBREG>: If WORD_REGISTER_OPERATIONS is
set and LOAD_EXTEND_OP is appropriate, propagate results from inner
REGs to paradoxical SUBREGs.
(num_sign_bit_copies1) <SUBREG>: Likewise. Check that the mode is not
larger than a word before invoking LOAD_EXTEND_OP on it.
From-SVN: r242326
