Would those that know, (or even those that are just generally vocal) be willing to support a change rtl.texi for sign_extract (and by implication, zero_extract) from
If @var{loc} is in memory, its mode must be a single-byte integer mode. If @var{loc} is in a register, the mode to use is specified by the operand of the @code{insv} or @code{extv} pattern (@pxref{Standard Names}) and is usually a full-word integer mode, which is the default if none is specified. to a version that explicitly prohibits the use of a mode longer than a word? The back ends do not appear to support this anyway. Kenny