Is there a way to adjust alignment of DImode and DFmode?

[H.J. Lu]

By default, alignment of DImode and DFmode is set to 8 bytes.
Intel MCU psABI specifies alignment of DImode and DFmode
to be 4 bytes. I'd like to make get_mode_alignment to return
32 bits for DImode and DFmode.   Is there a way to adjust alignment
of DImode and DFmode via ADJUST_ALIGNMENT?

-- 
H.J.