instr	$0, R5, R9;		\
	instr	$0, R6, R10;		\
	instr	$0, R7, R11;		\
	STP.P	(R8, R9), 32(R3);	\
	STP	(R10, R11), -16(R3);	\
	SUB	$4, counter;

// do one iteration of copy in addVW/subVW
#define vwOneIterCopy(counter, exit)			\
	CBZ	counter, exit;				\
	LDP.P	32(R1), (R4, R5);			\
	LDP	-16(R1), (R6, R7);			\
	STP.P	(R4, R5), 32(R3);			\
	STP	(R6, R7), -16(R3);			\
	SUB	$4, counter;

	ADD R0>>51, R11, R11
	ADD R1>>51, R12, R12
	ADD R2>>51, R13, R13
	ADD R3>>51, R14, R14
	// R4>>51 * 19 + R10 -> R10
	LSR $51, R4, R21
	MOVD $19, R22
	MADD R22, R10, R21, R10

	STP (R10, R11), 0(R20)
	STP (R12, R13), 16(R20)
	MOVD R14, 32(R20)

		LDP.P	16(b_ptr), (acc2, acc3)
		CSEL	EQ, acc2, t2, t2
		CSEL	EQ, acc3, t3, t3

		CMP	$16, const1
		BNE	loop_select

	STP	(x0, x1), 0*16(res_ptr)
	STP	(x2, x3), 1*16(res_ptr)
	STP	(y0, y1), 2*16(res_ptr)
	STP	(y2, y3), 3*16(res_ptr)
	STP	(t0, t1), 4*16(res_ptr)
	STP	(t2, t3), 5*16(res_ptr)
	RET
/* ---------------------------------------*/

	// but we are not called from Go so that space is ours to use,
	// and we must to be contiguous with the stack arguments.
	MOVD	$arg0-(7*8)(SP), R14
	STP	(R0, R1), (0*8)(R14)
	STP	(R2, R3), (2*8)(R14)
	STP	(R4, R5), (4*8)(R14)
	STP	(R6, R7), (6*8)(R14)

	// Push C callee-save registers R19-R28.
	// LR, FP already saved.
	SAVE_R19_TO_R28(8*9)

	// Create a struct callbackArgs on our stack.

	// R0 and R1 already saved
	STP	(R2, R3), 1*8(RSP)
	STP	(R4, R5), 3*8(RSP)
	STP	(R6, R7), 5*8(RSP)
	STP	(R8, R9), 7*8(RSP)
	STP	(R10, R11), 9*8(RSP)
	STP	(R12, R13), 11*8(RSP)
	STP	(R14, R15), 13*8(RSP)
	// R16, R17 may be clobbered by linker trampoline
	// R18 is unused.
	STP	(R19, R20), 15*8(RSP)
	STP	(R21, R22), 17*8(RSP)
	STP	(R23, R24), 19*8(RSP)
	STP	(R25, R26), 21*8(RSP)

	 *  push 3 args for fn (R0, R1, R3), skipping R2.
	 * Also note that at procedure entry in gc world, 8(RSP) will be the
	 *  first arg.
	 */
	SUB	$(8*24), RSP
	STP	(R0, R1), (8*1)(RSP)
	MOVD	R3, (8*3)(RSP)

	SAVE_R19_TO_R28(8*4)
	SAVE_F8_TO_F15(8*14)
	STP	(R29, R30), (8*22)(RSP)


	// Initialize Go ABI environment
	BL	runtime·load_g(SB)
	BL	runtime·cgocallback(SB)

	RESTORE_R19_TO_R28(8*4)

	LDPSW	8(R1), (ZR, R2)     // 3f084169
	STP	(R3, R4), (R5)      // a31000a9
	STP	(R3, R4), 8(R5)     // a39000a9
	STP.W	(R3, R4), 8(R5)     // a39080a9
	STP.P	(R3, R4), 8(R5)     // a39080a8
	STP	(R3, R4), -8(R5)    // a3903fa9
	STP	(R3, R4), -4(R5)    // bb1000d1631300a9
	STP	(R3, R4), 11(R0)    // 1b2c0091631300a9
	STP	(R3, R4), 1024(R0)  // 1b001091631300a9
	STP	(R3, R4), (RSP)     // e31300a9

	_, _ = w1[3], w2[3]
	w1[0], w1[1], w1[2], w1[3] = 0, 0, 0, 0 // arm64:"STP",-"MOVB",-"MOVH"
	w2[2], w2[3], w2[1], w2[0] = 0, 0, 0, 0 // arm64:"STP",-"MOVB",-"MOVH"
}

func zero_uint64_2(d1, d2 []uint64) {
	_, _ = d1[1], d2[1]
	d1[0], d1[1] = 0, 0 // arm64:"STP",-"MOVB",-"MOVH"
	d2[1], d2[0] = 0, 0 // arm64:"STP",-"MOVB",-"MOVH"
}

func loadstore(p, q *[4]uint8) {
	// amd64:"MOVL",-"MOVB"

	MOVD.W 	16(R2), R2                                       // ERROR "constrained unpredictable behavior"
	STP	(F2, F3), (R0)                                   // ERROR "invalid register pair"
	STP.W	(R1, R2), 8(R1)                                  // ERROR "constrained unpredictable behavior"
	STP.P	(R1, R2), 8(R2)                                  // ERROR "constrained unpredictable behavior"

		(MOVDstore ptr (MOVDconst [0]) mem))
(Zero [16] ptr mem) =>
	(STP [0] ptr (MOVDconst [0]) (MOVDconst [0]) mem)

(Zero [32] ptr mem) =>
	(STP [16] ptr (MOVDconst [0]) (MOVDconst [0])
		(STP [0] ptr (MOVDconst [0]) (MOVDconst [0]) mem))

(Zero [48] ptr mem) =>
	(STP [32] ptr (MOVDconst [0]) (MOVDconst [0])
		(STP [16] ptr (MOVDconst [0]) (MOVDconst [0])
			(STP [0] ptr (MOVDconst [0]) (MOVDconst [0]) mem)))