x	ADDIS
	must not be used for constant formation of unsigned values
x	LCON, UCON
x	D_DCONST
x	shift and RLWIMI, RLD etc
-	dynld
-	9db from qdb.c (or same)
x	MOVD
x	MOVW/MOVWZ in macro forms for register-register move with sign-extension or zero extension
	-> EXTSW or RLWNM to and
x	CMP vs CMPW/CMPWU
x	getmask -> uvlong
x	32-bit special registers require MOVW/MOVWZ; others require MOVD

notes
ZCON	0
SCON	16-bit signed
UCON	low 16-bits zero
ADDCON	-8000<= v < 0
ANDCON	0 <= v <= 0xFFFF
LCON	other
LECON	will be 64 bits