ADDV	$-7, R9, R6 // R6 is end pointer-7

	PCALIGN	$16
	SGTU	R6, R4, R8
	BEQ	R8, out
	MOVV	(R5), R7
	ADDV	$8, R5
	MOVV	R7, (R4)
	ADDV	$8, R4
	JMP	-6(PC)

out:
	BEQ	R4, R9, done
	MOVB	(R5), R7
	ADDV	$1, R5
	MOVB	R7, (R4)
	ADDV	$1, R4
	JMP	-5(PC)
done:
	RET

backward:
	ADDV	R6, R5 // from-end pointer
	ADDV	R4, R6, R9 // to-end pointer

	LDADDLD	R5, (R6), ZR                         // df0065f8
	LDADDLW	R5, (R6), ZR                         // df0065b8
	LDADDLH	R5, (R6), ZR                         // df006578
	LDADDLB	R5, (R6), ZR                         // df006538
	LDCLRD	R5, (R6), ZR                         // df1025f8
	LDCLRW	R5, (R6), ZR                         // df1025b8
	LDCLRH	R5, (R6), ZR                         // df102578

	ADD	$32, R8
	ADD	$-32, R6
	CMP	R6, $8
	BLE	small
	// Case for 8 <= n < 32 bytes
	// Process 16 bytes if available
xor16:
	CMP	R6, $16
	BLT	xor8
	LXVD2X	(R4)(R8), VS32
	LXVD2X	(R5)(R8), VS33
	XXLXOR	VS32, VS33, VS32
	STXVD2X	VS32, (R3)(R8)
	ADD	$16, R8
	ADD	$-16, R6
small:
	CMP	R6, $0
	BC	12,2,LR		// BEQLR
xor8:
#ifdef GOPPC64_power10
	SLD	$56,R6,R17
	ADD	R4,R8,R18
	ADD	R5,R8,R19

	MOVD	ptr+0(FP), R4
	MOVW	new+8(FP), R3
	MOVW	(R4), R6
repeat:
	CS	R6, R3, (R4) // if R6==(R4) then (R4)=R3 else R6=(R4)
	BNE	repeat
	MOVW	R6, ret+16(FP)
	RET

// func Xchg64(ptr *uint64, new uint64) uint64
TEXT ·Xchg64(SB), NOSPLIT, $0-24
	MOVD	ptr+0(FP), R4
	MOVD	new+8(FP), R3
	MOVD	(R4), R6
repeat:
	CSG	R6, R3, (R4) // if R6==(R4) then (R4)=R3 else R6=(R4)
	BNE	repeat
	MOVD	R6, ret+16(FP)
	RET

	MOVD.W	-8(R2), R6
	LSR	R4, R6, R5	// return value
	LSL	R3, R6, R8	// x[i] << s
	SUB	$1, R1
one:	TBZ	$0, R1, two
	MOVD.W	-8(R2), R6
	LSR	R4, R6, R7
	ORR	R8, R7
	LSL	R3, R6, R8
	SUB	$1, R1
	MOVD.W	R7, -8(R0)
two:
	TBZ	$1, R1, loop
	LDP.W	-16(R2), (R6, R7)
	LSR	R4, R7, R10
	ORR	R8, R10
	LSL	R3, R7
	LSR	R4, R6, R9
	ORR	R7, R9
	LSL	R3, R6, R8
	SUB	$2, R1

	MOVD	(R1), R5
	EOR	R4, R5
	CBNZ	R5, not_equal
	SUB	$8, R2, R6	// offset of the last 8 bytes
	MOVD	(R0)(R6), R4
	MOVD	(R1)(R6), R5
	EOR	R4, R5
	CBNZ	R5, not_equal
	B	equal
lt_8:
	TBZ	$2, R2, lt_4
	MOVWU	(R0), R4
	MOVWU	(R1), R5
	EOR	R4, R5
	CBNZ	R5, not_equal
	SUB	$4, R2, R6	// offset of the last 4 bytes
	MOVWU	(R0)(R6), R4
	MOVWU	(R1)(R6), R5
	EOR	R4, R5
	CBNZ	R5, not_equal
	B	equal
lt_4:

	RLWNM $3, R4, $29, $31, R6      // 54861f7e
	RLWNM $0, R4, $29, $31, R6      // 5486077e
	RLWNM R0, R4, $29, $31, R6      // 5c86077e
	RLWNM R3, R4, $7, R6            // 5c861f7e
	RLWNM R3, R4, $29, $31, R6      // 5c861f7e
	RLWNMCC $3, R4, $7, R6          // 54861f7f
	RLWNMCC $3, R4, $29, $31, R6    // 54861f7f
	RLWNMCC R3, R4, $7, R6          // 5c861f7f
	RLWNMCC R3, R4, $29, $31, R6    // 5c861f7f
	RLDMI $0, R4, $7, R6            // 7886076c

TEXT ·addMulVVW1024(SB), $0-32
	MOVD	$4, R6 // R6 = z_len/4
	JMP		addMulVVWx<>(SB)

// func addMulVVW1536(z, x *uint, y uint) (c uint)
TEXT ·addMulVVW1536(SB), $0-32
	MOVD	$6, R6 // R6 = z_len/4
	JMP		addMulVVWx<>(SB)

// func addMulVVW2048(z, x *uint, y uint) (c uint)
TEXT ·addMulVVW2048(SB), $0-32
	MOVD	$8, R6 // R6 = z_len/4
	JMP		addMulVVWx<>(SB)

// a1  | R5          | R4
// a2  | R6          | R5
// a3  | R7          | R6
// a4  | R8          | R7
// a5  | R9          | R8
// a6  | R10         | R9
//
// r1  | R4          | R4
// r2  | R5          | R5
// err | R6          | part of R4
TEXT ·Syscall6<ABIInternal>(SB),NOSPLIT,$0-80
	MOVV	R4, R11  // syscall entry
	MOVV	R5, R4
	MOVV	R6, R5
	MOVV	R7, R6
	MOVV	R8, R7
	MOVV	R9, R8
	MOVV	R10, R9

	LMG  0(R8), R5, R6
	MOVD $0, 0(R9)          // R9 address of SAVSTACK_ASYNC
	LE_CALL                 // balr R7, R6 (return #1)
	NOPH
	MOVD R3, ret+32(FP)
	CMP  R3, $-1            // compare result to -1
	BNE  done

	// retrieve errno and errno2
	MOVD  zosLibVec<>(SB), R8
	ADD   $(__errno), R8
	LMG   0(R8), R5, R6
	LE_CALL                   // balr R7, R6 __errno (return #3)
	NOPH