// amd64:"NEGL","ADCQ","SBBQ","NEGQ"
	// loong64: "ADDV", "SGTU"
	// ppc64x: "ADDC", "ADDE", "ADDZE"
	// s390x:"ADDE","ADDC\t[$]-1,"
	// mips64:"ADDV","SGTU"
	// riscv64: "ADD","SLTU"
	return bits.Add(x, 7, ci)
}

func AddZ(x, y uint) (r, co uint) {
	// arm64:"ADDS","ADC",-"ADCS",-"ADD\t",-"CMP"
	// amd64:"ADDQ","SBBQ","NEGQ",-"NEGL",-"ADCQ"
	// loong64: "ADDV", "SGTU"
	// ppc64x: "ADDC", -"ADDE", "ADDZE"

	NO_LOCAL_POINTERS;			\
	/* copy arguments to stack */		\
	MOVV	arg+16(FP), R4;			\
	MOVWU	argsize+24(FP), R5;			\
	MOVV	R3, R12;				\
	ADDV	$8, R12;			\
	ADDV	R12, R5;				\
	BEQ	R12, R5, 6(PC);				\
	MOVBU	(R4), R6;			\
	ADDV	$1, R4;			\
	MOVBU	R6, (R12);			\
	ADDV	$1, R12;			\
	JMP	-5(PC);				\
	/* set up argument registers */		\
	MOVV	regArgs+40(FP), R25;		\
	JAL	·unspillArgs(SB);		\