strict_low_part question

[Falk Hueffner]

Hi,

I'm playing with a byteswap builtin, and I would like to expand
bswap:SI in optabs.c to 3 rotations (rotate low 16 bits by 8, rotate
32 bits by 16, rotate low 16 bits by 8; that should give optimal code
on m68k and i386). However, the rotations of the low bits need to
leave the high bits unchanged, and I can't seem to be able to emit RTL
that does this. Can I use strict_low_part somehow? Or do I need iors
etc? Any hints appreciated...

-- 
	Falk