;
; jdsamss2.asm - upsampling (64-bit SSE2)
;
; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
; Copyright 2009 D. R. Commander
;
; Based on
; x86 SIMD extension for IJG JPEG library
; Copyright (C) 1999-2006, MIYASAKA Masaru.
; For conditions of distribution and use, see copyright notice in jsimdext.inc
;
; This file should be assembled with NASM (Netwide Assembler),
; can *not* be assembled with Microsoft's MASM or any compatible
; assembler (including Borland's Turbo Assembler).
; NASM is available from http://nasm.sourceforge.net/ or
; http://sourceforge.net/project/showfiles.php?group_id=6208
;
; [TAB8]

%include "jsimdext.inc"

; --------------------------------------------------------------------------
	SECTION	SEG_CONST

	alignz	16
	global	EXTN(jconst_fancy_upsample_sse2)

EXTN(jconst_fancy_upsample_sse2):

PW_ONE		times 8 dw  1
PW_TWO		times 8 dw  2
PW_THREE	times 8 dw  3
PW_SEVEN	times 8 dw  7
PW_EIGHT	times 8 dw  8

	alignz	16

; --------------------------------------------------------------------------
	SECTION	SEG_TEXT
	BITS	64
;
; Fancy processing for the common case of 2:1 horizontal and 1:1 vertical.
;
; The upsampling algorithm is linear interpolation between pixel centers,
; also known as a "triangle filter".  This is a good compromise between
; speed and visual quality.  The centers of the output pixels are 1/4 and 3/4
; of the way between input pixel centers.
;
; GLOBAL(void)
; jsimd_h2v1_fancy_upsample_sse2 (int max_v_samp_factor,
;                                 JDIMENSION downsampled_width,
;                                 JSAMPARRAY input_data,
;                                 JSAMPARRAY * output_data_ptr);
;

; r10 = int max_v_samp_factor
; r11 = JDIMENSION downsampled_width
; r12 = JSAMPARRAY input_data
; r13 = JSAMPARRAY * output_data_ptr

	align	16
	global	EXTN(jsimd_h2v1_fancy_upsample_sse2)

EXTN(jsimd_h2v1_fancy_upsample_sse2):
	push	rbp
	mov	rbp,rsp
	collect_args

	mov	rax, r11  ; colctr
	test	rax,rax
	jz	near .return

	mov	rcx, r10	; rowctr
	test	rcx,rcx
	jz	near .return

	mov	rsi, r12	; input_data
	mov	rdi, r13
	mov	rdi, JSAMPARRAY [rdi]			; output_data
.rowloop:
	push	rax			; colctr
	push	rdi
	push	rsi

	mov	rsi, JSAMPROW [rsi]	; inptr
	mov	rdi, JSAMPROW [rdi]	; outptr

	test	rax, SIZEOF_XMMWORD-1
	jz	short .skip
	mov	dl, JSAMPLE [rsi+(rax-1)*SIZEOF_JSAMPLE]
	mov	JSAMPLE [rsi+rax*SIZEOF_JSAMPLE], dl	; insert a dummy sample
.skip:
	pxor	xmm0,xmm0		; xmm0=(all 0's)
	pcmpeqb	xmm7,xmm7
	psrldq	xmm7,(SIZEOF_XMMWORD-1)
	pand	xmm7, XMMWORD [rsi+0*SIZEOF_XMMWORD]

	add	rax, byte SIZEOF_XMMWORD-1
	and	rax, byte -SIZEOF_XMMWORD
	cmp	rax, byte SIZEOF_XMMWORD
	ja	short .columnloop

.columnloop_last:
	pcmpeqb	xmm6,xmm6
	pslldq	xmm6,(SIZEOF_XMMWORD-1)
	pand	xmm6, XMMWORD [rsi+0*SIZEOF_XMMWORD]
	jmp	short .upsample

.columnloop:
	movdqa	xmm6, XMMWORD [rsi+1*SIZEOF_XMMWORD]
	pslldq	xmm6,(SIZEOF_XMMWORD-1)

.upsample:
	movdqa	xmm1, XMMWORD [rsi+0*SIZEOF_XMMWORD]
	movdqa	xmm2,xmm1
	movdqa	xmm3,xmm1		; xmm1=( 0  1  2 ... 13 14 15)
	pslldq	xmm2,1			; xmm2=(--  0  1 ... 12 13 14)
	psrldq	xmm3,1			; xmm3=( 1  2  3 ... 14 15 --)

	por	xmm2,xmm7		; xmm2=(-1  0  1 ... 12 13 14)
	por	xmm3,xmm6		; xmm3=( 1  2  3 ... 14 15 16)

	movdqa	xmm7,xmm1
	psrldq	xmm7,(SIZEOF_XMMWORD-1)	; xmm7=(15 -- -- ... -- -- --)

	movdqa    xmm4,xmm1
	punpcklbw xmm1,xmm0		; xmm1=( 0  1  2  3  4  5  6  7)
	punpckhbw xmm4,xmm0		; xmm4=( 8  9 10 11 12 13 14 15)
	movdqa    xmm5,xmm2
	punpcklbw xmm2,xmm0		; xmm2=(-1  0  1  2  3  4  5  6)
	punpckhbw xmm5,xmm0		; xmm5=( 7  8  9 10 11 12 13 14)
	movdqa    xmm6,xmm3
	punpcklbw xmm3,xmm0		; xmm3=( 1  2  3  4  5  6  7  8)
	punpckhbw xmm6,xmm0		; xmm6=( 9 10 11 12 13 14 15 16)

	pmullw	xmm1,[PW_THREE]
	pmullw	xmm4,[PW_THREE]
	paddw	xmm2,[PW_ONE]
	paddw	xmm5,[PW_ONE]
	paddw	xmm3,[PW_TWO]
	paddw	xmm6,[PW_TWO]

	paddw	xmm2,xmm1
	paddw	xmm5,xmm4
	psrlw	xmm2,2			; xmm2=OutLE=( 0  2  4  6  8 10 12 14)
	psrlw	xmm5,2			; xmm5=OutHE=(16 18 20 22 24 26 28 30)
	paddw	xmm3,xmm1
	paddw	xmm6,xmm4
	psrlw	xmm3,2			; xmm3=OutLO=( 1  3  5  7  9 11 13 15)
	psrlw	xmm6,2			; xmm6=OutHO=(17 19 21 23 25 27 29 31)

	psllw	xmm3,BYTE_BIT
	psllw	xmm6,BYTE_BIT
	por	xmm2,xmm3		; xmm2=OutL=( 0  1  2 ... 13 14 15)
	por	xmm5,xmm6		; xmm5=OutH=(16 17 18 ... 29 30 31)

	movdqa	XMMWORD [rdi+0*SIZEOF_XMMWORD], xmm2
	movdqa	XMMWORD [rdi+1*SIZEOF_XMMWORD], xmm5

	sub	rax, byte SIZEOF_XMMWORD
	add	rsi, byte 1*SIZEOF_XMMWORD	; inptr
	add	rdi, byte 2*SIZEOF_XMMWORD	; outptr
	cmp	rax, byte SIZEOF_XMMWORD
	ja	near .columnloop
	test	eax,eax
	jnz	near .columnloop_last

	pop	rsi
	pop	rdi
	pop	rax

	add	rsi, byte SIZEOF_JSAMPROW	; input_data
	add	rdi, byte SIZEOF_JSAMPROW	; output_data
	dec	rcx				; rowctr
	jg	near .rowloop

.return:
	uncollect_args
	pop	rbp
	ret

; --------------------------------------------------------------------------
;
; Fancy processing for the common case of 2:1 horizontal and 2:1 vertical.
; Again a triangle filter; see comments for h2v1 case, above.
;
; GLOBAL(void)
; jsimd_h2v2_fancy_upsample_sse2 (int max_v_samp_factor,
;                                 JDIMENSION downsampled_width,
;                                 JSAMPARRAY input_data,
;                                 JSAMPARRAY * output_data_ptr);
;

; r10 = int max_v_samp_factor
; r11 = JDIMENSION downsampled_width
; r12 = JSAMPARRAY input_data
; r13 = JSAMPARRAY * output_data_ptr

%define wk(i)		rbp-(WK_NUM-(i))*SIZEOF_XMMWORD	; xmmword wk[WK_NUM]
%define WK_NUM		4

	align	16
	global	EXTN(jsimd_h2v2_fancy_upsample_sse2)

EXTN(jsimd_h2v2_fancy_upsample_sse2):
	push	rbp
	mov	rax,rsp				; rax = original rbp
	sub	rsp, byte 4
	and	rsp, byte (-SIZEOF_XMMWORD)	; align to 128 bits
	mov	[rsp],rax
	mov	rbp,rsp				; rbp = aligned rbp
	lea	rsp, [wk(0)]
	push	rbx
	collect_args

	mov	rax, r11  ; colctr
	test	rax,rax
	jz	near .return

	mov	rcx, r10	; rowctr
	test	rcx,rcx
	jz	near .return

	mov	rsi, r12	; input_data
	mov	rdi, r13
	mov	rdi, JSAMPARRAY [rdi]			; output_data
.rowloop:
	push	rax					; colctr
	push	rcx
	push	rdi
	push	rsi

	mov	rcx, JSAMPROW [rsi-1*SIZEOF_JSAMPROW]	; inptr1(above)
	mov	rbx, JSAMPROW [rsi+0*SIZEOF_JSAMPROW]	; inptr0
	mov	rsi, JSAMPROW [rsi+1*SIZEOF_JSAMPROW]	; inptr1(below)
	mov	rdx, JSAMPROW [rdi+0*SIZEOF_JSAMPROW]	; outptr0
	mov	rdi, JSAMPROW [rdi+1*SIZEOF_JSAMPROW]	; outptr1

	test	rax, SIZEOF_XMMWORD-1
	jz	short .skip
	push	rdx
	mov	dl, JSAMPLE [rcx+(rax-1)*SIZEOF_JSAMPLE]
	mov	JSAMPLE [rcx+rax*SIZEOF_JSAMPLE], dl
	mov	dl, JSAMPLE [rbx+(rax-1)*SIZEOF_JSAMPLE]
	mov	JSAMPLE [rbx+rax*SIZEOF_JSAMPLE], dl
	mov	dl, JSAMPLE [rsi+(rax-1)*SIZEOF_JSAMPLE]
	mov	JSAMPLE [rsi+rax*SIZEOF_JSAMPLE], dl	; insert a dummy sample
	pop	rdx
.skip:
	; -- process the first column block

	movdqa	xmm0, XMMWORD [rbx+0*SIZEOF_XMMWORD]	; xmm0=row[ 0][0]
	movdqa	xmm1, XMMWORD [rcx+0*SIZEOF_XMMWORD]	; xmm1=row[-1][0]
	movdqa	xmm2, XMMWORD [rsi+0*SIZEOF_XMMWORD]	; xmm2=row[+1][0]

	pxor      xmm3,xmm3		; xmm3=(all 0's)
	movdqa    xmm4,xmm0
	punpcklbw xmm0,xmm3		; xmm0=row[ 0]( 0  1  2  3  4  5  6  7)
	punpckhbw xmm4,xmm3		; xmm4=row[ 0]( 8  9 10 11 12 13 14 15)
	movdqa    xmm5,xmm1
	punpcklbw xmm1,xmm3		; xmm1=row[-1]( 0  1  2  3  4  5  6  7)
	punpckhbw xmm5,xmm3		; xmm5=row[-1]( 8  9 10 11 12 13 14 15)
	movdqa    xmm6,xmm2
	punpcklbw xmm2,xmm3		; xmm2=row[+1]( 0  1  2  3  4  5  6  7)
	punpckhbw xmm6,xmm3		; xmm6=row[+1]( 8  9 10 11 12 13 14 15)

	pmullw	xmm0,[PW_THREE]
	pmullw	xmm4,[PW_THREE]

	pcmpeqb	xmm7,xmm7
	psrldq	xmm7,(SIZEOF_XMMWORD-2)

	paddw	xmm1,xmm0		; xmm1=Int0L=( 0  1  2  3  4  5  6  7)
	paddw	xmm5,xmm4		; xmm5=Int0H=( 8  9 10 11 12 13 14 15)
	paddw	xmm2,xmm0		; xmm2=Int1L=( 0  1  2  3  4  5  6  7)
	paddw	xmm6,xmm4		; xmm6=Int1H=( 8  9 10 11 12 13 14 15)

	movdqa	XMMWORD [rdx+0*SIZEOF_XMMWORD], xmm1	; temporarily save
	movdqa	XMMWORD [rdx+1*SIZEOF_XMMWORD], xmm5	; the intermediate data
	movdqa	XMMWORD [rdi+0*SIZEOF_XMMWORD], xmm2
	movdqa	XMMWORD [rdi+1*SIZEOF_XMMWORD], xmm6

	pand	xmm1,xmm7		; xmm1=( 0 -- -- -- -- -- -- --)
	pand	xmm2,xmm7		; xmm2=( 0 -- -- -- -- -- -- --)

	movdqa	XMMWORD [wk(0)], xmm1
	movdqa	XMMWORD [wk(1)], xmm2

	add	rax, byte SIZEOF_XMMWORD-1
	and	rax, byte -SIZEOF_XMMWORD
	cmp	rax, byte SIZEOF_XMMWORD
	ja	short .columnloop

.columnloop_last:
	; -- process the last column block

	pcmpeqb	xmm1,xmm1
	pslldq	xmm1,(SIZEOF_XMMWORD-2)
	movdqa	xmm2,xmm1

	pand	xmm1, XMMWORD [edx+1*SIZEOF_XMMWORD]
	pand	xmm2, XMMWORD [edi+1*SIZEOF_XMMWORD]

	movdqa	XMMWORD [wk(2)], xmm1	; xmm1=(-- -- -- -- -- -- -- 15)
	movdqa	XMMWORD [wk(3)], xmm2	; xmm2=(-- -- -- -- -- -- -- 15)

	jmp	near .upsample

.columnloop:
	; -- process the next column block

	movdqa	xmm0, XMMWORD [rbx+1*SIZEOF_XMMWORD]	; xmm0=row[ 0][1]
	movdqa	xmm1, XMMWORD [rcx+1*SIZEOF_XMMWORD]	; xmm1=row[-1][1]
	movdqa	xmm2, XMMWORD [rsi+1*SIZEOF_XMMWORD]	; xmm2=row[+1][1]

	pxor      xmm3,xmm3		; xmm3=(all 0's)
	movdqa    xmm4,xmm0
	punpcklbw xmm0,xmm3		; xmm0=row[ 0]( 0  1  2  3  4  5  6  7)
	punpckhbw xmm4,xmm3		; xmm4=row[ 0]( 8  9 10 11 12 13 14 15)
	movdqa    xmm5,xmm1
	punpcklbw xmm1,xmm3		; xmm1=row[-1]( 0  1  2  3  4  5  6  7)
	punpckhbw xmm5,xmm3		; xmm5=row[-1]( 8  9 10 11 12 13 14 15)
	movdqa    xmm6,xmm2
	punpcklbw xmm2,xmm3		; xmm2=row[+1]( 0  1  2  3  4  5  6  7)
	punpckhbw xmm6,xmm3		; xmm6=row[+1]( 8  9 10 11 12 13 14 15)

	pmullw	xmm0,[PW_THREE]
	pmullw	xmm4,[PW_THREE]

	paddw	xmm1,xmm0		; xmm1=Int0L=( 0  1  2  3  4  5  6  7)
	paddw	xmm5,xmm4		; xmm5=Int0H=( 8  9 10 11 12 13 14 15)
	paddw	xmm2,xmm0		; xmm2=Int1L=( 0  1  2  3  4  5  6  7)
	paddw	xmm6,xmm4		; xmm6=Int1H=( 8  9 10 11 12 13 14 15)

	movdqa	XMMWORD [rdx+2*SIZEOF_XMMWORD], xmm1	; temporarily save
	movdqa	XMMWORD [rdx+3*SIZEOF_XMMWORD], xmm5	; the intermediate data
	movdqa	XMMWORD [rdi+2*SIZEOF_XMMWORD], xmm2
	movdqa	XMMWORD [rdi+3*SIZEOF_XMMWORD], xmm6

	pslldq	xmm1,(SIZEOF_XMMWORD-2)	; xmm1=(-- -- -- -- -- -- --  0)
	pslldq	xmm2,(SIZEOF_XMMWORD-2)	; xmm2=(-- -- -- -- -- -- --  0)

	movdqa	XMMWORD [wk(2)], xmm1
	movdqa	XMMWORD [wk(3)], xmm2

.upsample:
	; -- process the upper row

	movdqa	xmm7, XMMWORD [rdx+0*SIZEOF_XMMWORD]
	movdqa	xmm3, XMMWORD [rdx+1*SIZEOF_XMMWORD]

	movdqa	xmm0,xmm7		; xmm7=Int0L=( 0  1  2  3  4  5  6  7)
	movdqa	xmm4,xmm3		; xmm3=Int0H=( 8  9 10 11 12 13 14 15)
	psrldq	xmm0,2			; xmm0=( 1  2  3  4  5  6  7 --)
	pslldq	xmm4,(SIZEOF_XMMWORD-2)	; xmm4=(-- -- -- -- -- -- --  8)
	movdqa	xmm5,xmm7
	movdqa	xmm6,xmm3
	psrldq	xmm5,(SIZEOF_XMMWORD-2)	; xmm5=( 7 -- -- -- -- -- -- --)
	pslldq	xmm6,2			; xmm6=(--  8  9 10 11 12 13 14)

	por	xmm0,xmm4		; xmm0=( 1  2  3  4  5  6  7  8)
	por	xmm5,xmm6		; xmm5=( 7  8  9 10 11 12 13 14)

	movdqa	xmm1,xmm7
	movdqa	xmm2,xmm3
	pslldq	xmm1,2			; xmm1=(--  0  1  2  3  4  5  6)
	psrldq	xmm2,2			; xmm2=( 9 10 11 12 13 14 15 --)
	movdqa	xmm4,xmm3
	psrldq	xmm4,(SIZEOF_XMMWORD-2)	; xmm4=(15 -- -- -- -- -- -- --)

	por	xmm1, XMMWORD [wk(0)]	; xmm1=(-1  0  1  2  3  4  5  6)
	por	xmm2, XMMWORD [wk(2)]	; xmm2=( 9 10 11 12 13 14 15 16)

	movdqa	XMMWORD [wk(0)], xmm4

	pmullw	xmm7,[PW_THREE]
	pmullw	xmm3,[PW_THREE]
	paddw	xmm1,[PW_EIGHT]
	paddw	xmm5,[PW_EIGHT]
	paddw	xmm0,[PW_SEVEN]
	paddw	xmm2,[PW_SEVEN]

	paddw	xmm1,xmm7
	paddw	xmm5,xmm3
	psrlw	xmm1,4			; xmm1=Out0LE=( 0  2  4  6  8 10 12 14)
	psrlw	xmm5,4			; xmm5=Out0HE=(16 18 20 22 24 26 28 30)
	paddw	xmm0,xmm7
	paddw	xmm2,xmm3
	psrlw	xmm0,4			; xmm0=Out0LO=( 1  3  5  7  9 11 13 15)
	psrlw	xmm2,4			; xmm2=Out0HO=(17 19 21 23 25 27 29 31)

	psllw	xmm0,BYTE_BIT
	psllw	xmm2,BYTE_BIT
	por	xmm1,xmm0		; xmm1=Out0L=( 0  1  2 ... 13 14 15)
	por	xmm5,xmm2		; xmm5=Out0H=(16 17 18 ... 29 30 31)

	movdqa	XMMWORD [rdx+0*SIZEOF_XMMWORD], xmm1
	movdqa	XMMWORD [rdx+1*SIZEOF_XMMWORD], xmm5

	; -- process the lower row

	movdqa	xmm6, XMMWORD [rdi+0*SIZEOF_XMMWORD]
	movdqa	xmm4, XMMWORD [rdi+1*SIZEOF_XMMWORD]

	movdqa	xmm7,xmm6		; xmm6=Int1L=( 0  1  2  3  4  5  6  7)
	movdqa	xmm3,xmm4		; xmm4=Int1H=( 8  9 10 11 12 13 14 15)
	psrldq	xmm7,2			; xmm7=( 1  2  3  4  5  6  7 --)
	pslldq	xmm3,(SIZEOF_XMMWORD-2)	; xmm3=(-- -- -- -- -- -- --  8)
	movdqa	xmm0,xmm6
	movdqa	xmm2,xmm4
	psrldq	xmm0,(SIZEOF_XMMWORD-2)	; xmm0=( 7 -- -- -- -- -- -- --)
	pslldq	xmm2,2			; xmm2=(--  8  9 10 11 12 13 14)

	por	xmm7,xmm3		; xmm7=( 1  2  3  4  5  6  7  8)
	por	xmm0,xmm2		; xmm0=( 7  8  9 10 11 12 13 14)

	movdqa	xmm1,xmm6
	movdqa	xmm5,xmm4
	pslldq	xmm1,2			; xmm1=(--  0  1  2  3  4  5  6)
	psrldq	xmm5,2			; xmm5=( 9 10 11 12 13 14 15 --)
	movdqa	xmm3,xmm4
	psrldq	xmm3,(SIZEOF_XMMWORD-2)	; xmm3=(15 -- -- -- -- -- -- --)

	por	xmm1, XMMWORD [wk(1)]	; xmm1=(-1  0  1  2  3  4  5  6)
	por	xmm5, XMMWORD [wk(3)]	; xmm5=( 9 10 11 12 13 14 15 16)

	movdqa	XMMWORD [wk(1)], xmm3

	pmullw	xmm6,[PW_THREE]
	pmullw	xmm4,[PW_THREE]
	paddw	xmm1,[PW_EIGHT]
	paddw	xmm0,[PW_EIGHT]
	paddw	xmm7,[PW_SEVEN]
	paddw	xmm5,[PW_SEVEN]

	paddw	xmm1,xmm6
	paddw	xmm0,xmm4
	psrlw	xmm1,4			; xmm1=Out1LE=( 0  2  4  6  8 10 12 14)
	psrlw	xmm0,4			; xmm0=Out1HE=(16 18 20 22 24 26 28 30)
	paddw	xmm7,xmm6
	paddw	xmm5,xmm4
	psrlw	xmm7,4			; xmm7=Out1LO=( 1  3  5  7  9 11 13 15)
	psrlw	xmm5,4			; xmm5=Out1HO=(17 19 21 23 25 27 29 31)

	psllw	xmm7,BYTE_BIT
	psllw	xmm5,BYTE_BIT
	por	xmm1,xmm7		; xmm1=Out1L=( 0  1  2 ... 13 14 15)
	por	xmm0,xmm5		; xmm0=Out1H=(16 17 18 ... 29 30 31)

	movdqa	XMMWORD [rdi+0*SIZEOF_XMMWORD], xmm1
	movdqa	XMMWORD [rdi+1*SIZEOF_XMMWORD], xmm0

	sub	rax, byte SIZEOF_XMMWORD
	add	rcx, byte 1*SIZEOF_XMMWORD	; inptr1(above)
	add	rbx, byte 1*SIZEOF_XMMWORD	; inptr0
	add	rsi, byte 1*SIZEOF_XMMWORD	; inptr1(below)
	add	rdx, byte 2*SIZEOF_XMMWORD	; outptr0
	add	rdi, byte 2*SIZEOF_XMMWORD	; outptr1
	cmp	rax, byte SIZEOF_XMMWORD
	ja	near .columnloop
	test	rax,rax
	jnz	near .columnloop_last

	pop	rsi
	pop	rdi
	pop	rcx
	pop	rax

	add	rsi, byte 1*SIZEOF_JSAMPROW	; input_data
	add	rdi, byte 2*SIZEOF_JSAMPROW	; output_data
	sub	rcx, byte 2			; rowctr
	jg	near .rowloop

.return:
	uncollect_args
	pop	rbx
	mov	rsp,rbp		; rsp <- aligned rbp
	pop	rsp		; rsp <- original rbp
	pop	rbp
	ret

; --------------------------------------------------------------------------
;
; Fast processing for the common case of 2:1 horizontal and 1:1 vertical.
; It's still a box filter.
;
; GLOBAL(void)
; jsimd_h2v1_upsample_sse2 (int max_v_samp_factor,
;                           JDIMENSION output_width,
;                           JSAMPARRAY input_data,
;                           JSAMPARRAY * output_data_ptr);
;

; r10 = int max_v_samp_factor
; r11 = JDIMENSION output_width
; r12 = JSAMPARRAY input_data
; r13 = JSAMPARRAY * output_data_ptr

	align	16
	global	EXTN(jsimd_h2v1_upsample_sse2)

EXTN(jsimd_h2v1_upsample_sse2):
	push	rbp
	mov	rbp,rsp
	collect_args

	mov	rdx, r11
	add	rdx, byte (2*SIZEOF_XMMWORD)-1
	and	rdx, byte -(2*SIZEOF_XMMWORD)
	jz	near .return

	mov	rcx, r10	; rowctr
	test	rcx,rcx
	jz	short .return

	mov	rsi, r12 ; input_data
	mov	rdi, r13
	mov	rdi, JSAMPARRAY [rdi]			; output_data
.rowloop:
	push	rdi
	push	rsi

	mov	rsi, JSAMPROW [rsi]		; inptr
	mov	rdi, JSAMPROW [rdi]		; outptr
	mov	rax,rdx				; colctr
.columnloop:

	movdqa	xmm0, XMMWORD [rsi+0*SIZEOF_XMMWORD]

	movdqa    xmm1,xmm0
	punpcklbw xmm0,xmm0
	punpckhbw xmm1,xmm1

	movdqa	XMMWORD [rdi+0*SIZEOF_XMMWORD], xmm0
	movdqa	XMMWORD [rdi+1*SIZEOF_XMMWORD], xmm1

	sub	rax, byte 2*SIZEOF_XMMWORD
	jz	short .nextrow

	movdqa	xmm2, XMMWORD [rsi+1*SIZEOF_XMMWORD]

	movdqa    xmm3,xmm2
	punpcklbw xmm2,xmm2
	punpckhbw xmm3,xmm3

	movdqa	XMMWORD [rdi+2*SIZEOF_XMMWORD], xmm2
	movdqa	XMMWORD [rdi+3*SIZEOF_XMMWORD], xmm3

	sub	rax, byte 2*SIZEOF_XMMWORD
	jz	short .nextrow

	add	rsi, byte 2*SIZEOF_XMMWORD	; inptr
	add	rdi, byte 4*SIZEOF_XMMWORD	; outptr
	jmp	short .columnloop

.nextrow:
	pop	rsi
	pop	rdi

	add	rsi, byte SIZEOF_JSAMPROW	; input_data
	add	rdi, byte SIZEOF_JSAMPROW	; output_data
	dec	rcx				; rowctr
	jg	short .rowloop

.return:
	uncollect_args
	pop	rbp
	ret

; --------------------------------------------------------------------------
;
; Fast processing for the common case of 2:1 horizontal and 2:1 vertical.
; It's still a box filter.
;
; GLOBAL(void)
; jsimd_h2v2_upsample_sse2 (nt max_v_samp_factor,
;                           JDIMENSION output_width,
;                           JSAMPARRAY input_data,
;                           JSAMPARRAY * output_data_ptr);
;

; r10 = int max_v_samp_factor
; r11 = JDIMENSION output_width
; r12 = JSAMPARRAY input_data
; r13 = JSAMPARRAY * output_data_ptr

	align	16
	global	EXTN(jsimd_h2v2_upsample_sse2)

EXTN(jsimd_h2v2_upsample_sse2):
	push	rbp
	mov	rbp,rsp
	push	rbx
	collect_args

	mov	rdx, r11
	add	rdx, byte (2*SIZEOF_XMMWORD)-1
	and	rdx, byte -(2*SIZEOF_XMMWORD)
	jz	near .return

	mov	rcx, r10	; rowctr
	test	rcx,rcx
	jz	near .return

	mov	rsi, r12	; input_data
	mov	rdi, r13
	mov	rdi, JSAMPARRAY [rdi]			; output_data
.rowloop:
	push	rdi
	push	rsi

	mov	rsi, JSAMPROW [rsi]			; inptr
	mov	rbx, JSAMPROW [rdi+0*SIZEOF_JSAMPROW]	; outptr0
	mov	rdi, JSAMPROW [rdi+1*SIZEOF_JSAMPROW]	; outptr1
	mov	rax,rdx					; colctr
.columnloop:

	movdqa	xmm0, XMMWORD [rsi+0*SIZEOF_XMMWORD]

	movdqa    xmm1,xmm0
	punpcklbw xmm0,xmm0
	punpckhbw xmm1,xmm1

	movdqa	XMMWORD [rbx+0*SIZEOF_XMMWORD], xmm0
	movdqa	XMMWORD [rbx+1*SIZEOF_XMMWORD], xmm1
	movdqa	XMMWORD [rdi+0*SIZEOF_XMMWORD], xmm0
	movdqa	XMMWORD [rdi+1*SIZEOF_XMMWORD], xmm1

	sub	rax, byte 2*SIZEOF_XMMWORD
	jz	short .nextrow

	movdqa	xmm2, XMMWORD [rsi+1*SIZEOF_XMMWORD]

	movdqa    xmm3,xmm2
	punpcklbw xmm2,xmm2
	punpckhbw xmm3,xmm3

	movdqa	XMMWORD [rbx+2*SIZEOF_XMMWORD], xmm2
	movdqa	XMMWORD [rbx+3*SIZEOF_XMMWORD], xmm3
	movdqa	XMMWORD [rdi+2*SIZEOF_XMMWORD], xmm2
	movdqa	XMMWORD [rdi+3*SIZEOF_XMMWORD], xmm3

	sub	rax, byte 2*SIZEOF_XMMWORD
	jz	short .nextrow

	add	rsi, byte 2*SIZEOF_XMMWORD	; inptr
	add	rbx, byte 4*SIZEOF_XMMWORD	; outptr0
	add	rdi, byte 4*SIZEOF_XMMWORD	; outptr1
	jmp	short .columnloop

.nextrow:
	pop	rsi
	pop	rdi

	add	rsi, byte 1*SIZEOF_JSAMPROW	; input_data
	add	rdi, byte 2*SIZEOF_JSAMPROW	; output_data
	sub	rcx, byte 2			; rowctr
	jg	near .rowloop

.return:
	uncollect_args
	pop	rbx
	pop	rbp
	ret