jcclrss2-64.asm

;
; jcclrss2-64.asm - colorspace conversion (64-bit SSE2)
;
; x86 SIMD extension for IJG JPEG library
; Copyright (C) 1999-2006, MIYASAKA Masaru.
; Copyright (C) 2009, D. R. Commander.
; 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 "jcolsamp.inc"

; --------------------------------------------------------------------------
;
; Convert some rows of samples to the output colorspace.
;
; GLOBAL(void)
; jsimd_rgb_ycc_convert_sse2 (JDIMENSION img_width,
;                             JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
;                             JDIMENSION output_row, int num_rows);
;

; r10 = JDIMENSION img_width
; r11 = JSAMPARRAY input_buf
; r12 = JSAMPIMAGE output_buf
; r13 = JDIMENSION output_row
; r14 = int num_rows

%define wk(i)		rbp-(WK_NUM-(i))*SIZEOF_XMMWORD	; xmmword wk[WK_NUM]
%define WK_NUM		8

	align	16

	global	EXTN(jsimd_rgb_ycc_convert_sse2)

EXTN(jsimd_rgb_ycc_convert_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)]
	collect_args
	push	rbx

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

	push	rcx

	mov rsi, r12
	mov rcx, r13
	mov	rdi, JSAMPARRAY [rsi+0*SIZEOF_JSAMPARRAY]
	mov	rbx, JSAMPARRAY [rsi+1*SIZEOF_JSAMPARRAY]
	mov	rdx, JSAMPARRAY [rsi+2*SIZEOF_JSAMPARRAY]
	lea	rdi, [rdi+rcx*SIZEOF_JSAMPROW]
	lea	rbx, [rbx+rcx*SIZEOF_JSAMPROW]
	lea	rdx, [rdx+rcx*SIZEOF_JSAMPROW]

	pop	rcx

	mov rsi, r11
	mov	eax, r14d
	test	rax,rax
	jle	near .return
.rowloop:
	push	rdx
	push	rbx
	push	rdi
	push	rsi
	push	rcx			; col

	mov	rsi, JSAMPROW [rsi]	; inptr
	mov	rdi, JSAMPROW [rdi]	; outptr0
	mov	rbx, JSAMPROW [rbx]	; outptr1
	mov	rdx, JSAMPROW [rdx]	; outptr2

	cmp	rcx, byte SIZEOF_XMMWORD
	jae	near .columnloop

%if RGB_PIXELSIZE == 3 ; ---------------

.column_ld1:
	push	rax
	push	rdx
	lea	rcx,[rcx+rcx*2]		; imul ecx,RGB_PIXELSIZE
	test	cl, SIZEOF_BYTE
	jz	short .column_ld2
	sub	rcx, byte SIZEOF_BYTE
	movzx	rax, BYTE [rsi+rcx]
.column_ld2:
	test	cl, SIZEOF_WORD
	jz	short .column_ld4
	sub	rcx, byte SIZEOF_WORD
	movzx	rdx, WORD [rsi+rcx]
	shl	rax, WORD_BIT
	or	rax,rdx
.column_ld4:
	movd	xmmA,eax
	pop	rdx
	pop	rax
	test	cl, SIZEOF_DWORD
	jz	short .column_ld8
	sub	rcx, byte SIZEOF_DWORD
	movd	xmmF, XMM_DWORD [rsi+rcx]
	pslldq	xmmA, SIZEOF_DWORD
	por	xmmA,xmmF
.column_ld8:
	test	cl, SIZEOF_MMWORD
	jz	short .column_ld16
	sub	rcx, byte SIZEOF_MMWORD
	movq	xmmB, XMM_MMWORD [rsi+rcx]
	pslldq	xmmA, SIZEOF_MMWORD
	por	xmmA,xmmB
.column_ld16:
	test	cl, SIZEOF_XMMWORD
	jz	short .column_ld32
	movdqa	xmmF,xmmA
	movdqu	xmmA, XMMWORD [rsi+0*SIZEOF_XMMWORD]
	mov	rcx, SIZEOF_XMMWORD
	jmp	short .rgb_ycc_cnv
.column_ld32:
	test	cl, 2*SIZEOF_XMMWORD
	mov	rcx, SIZEOF_XMMWORD
	jz	short .rgb_ycc_cnv
	movdqa	xmmB,xmmA
	movdqu	xmmA, XMMWORD [rsi+0*SIZEOF_XMMWORD]
	movdqu	xmmF, XMMWORD [rsi+1*SIZEOF_XMMWORD]
	jmp	short .rgb_ycc_cnv

.columnloop:
	movdqu	xmmA, XMMWORD [rsi+0*SIZEOF_XMMWORD]
	movdqu	xmmF, XMMWORD [rsi+1*SIZEOF_XMMWORD]
	movdqu	xmmB, XMMWORD [rsi+2*SIZEOF_XMMWORD]

.rgb_ycc_cnv:
	; xmmA=(00 10 20 01 11 21 02 12 22 03 13 23 04 14 24 05)
	; xmmF=(15 25 06 16 26 07 17 27 08 18 28 09 19 29 0A 1A)
	; xmmB=(2A 0B 1B 2B 0C 1C 2C 0D 1D 2D 0E 1E 2E 0F 1F 2F)

	movdqa    xmmG,xmmA
	pslldq    xmmA,8	; xmmA=(-- -- -- -- -- -- -- -- 00 10 20 01 11 21 02 12)
	psrldq    xmmG,8	; xmmG=(22 03 13 23 04 14 24 05 -- -- -- -- -- -- -- --)

	punpckhbw xmmA,xmmF	; xmmA=(00 08 10 18 20 28 01 09 11 19 21 29 02 0A 12 1A)
	pslldq    xmmF,8	; xmmF=(-- -- -- -- -- -- -- -- 15 25 06 16 26 07 17 27)

	punpcklbw xmmG,xmmB	; xmmG=(22 2A 03 0B 13 1B 23 2B 04 0C 14 1C 24 2C 05 0D)
	punpckhbw xmmF,xmmB	; xmmF=(15 1D 25 2D 06 0E 16 1E 26 2E 07 0F 17 1F 27 2F)

	movdqa    xmmD,xmmA
	pslldq    xmmA,8	; xmmA=(-- -- -- -- -- -- -- -- 00 08 10 18 20 28 01 09)
	psrldq    xmmD,8	; xmmD=(11 19 21 29 02 0A 12 1A -- -- -- -- -- -- -- --)

	punpckhbw xmmA,xmmG	; xmmA=(00 04 08 0C 10 14 18 1C 20 24 28 2C 01 05 09 0D)
	pslldq    xmmG,8	; xmmG=(-- -- -- -- -- -- -- -- 22 2A 03 0B 13 1B 23 2B)

	punpcklbw xmmD,xmmF	; xmmD=(11 15 19 1D 21 25 29 2D 02 06 0A 0E 12 16 1A 1E)
	punpckhbw xmmG,xmmF	; xmmG=(22 26 2A 2E 03 07 0B 0F 13 17 1B 1F 23 27 2B 2F)

	movdqa    xmmE,xmmA
	pslldq    xmmA,8	; xmmA=(-- -- -- -- -- -- -- -- 00 04 08 0C 10 14 18 1C)
	psrldq    xmmE,8	; xmmE=(20 24 28 2C 01 05 09 0D -- -- -- -- -- -- -- --)

	punpckhbw xmmA,xmmD	; xmmA=(00 02 04 06 08 0A 0C 0E 10 12 14 16 18 1A 1C 1E)
	pslldq    xmmD,8	; xmmD=(-- -- -- -- -- -- -- -- 11 15 19 1D 21 25 29 2D)

	punpcklbw xmmE,xmmG	; xmmE=(20 22 24 26 28 2A 2C 2E 01 03 05 07 09 0B 0D 0F)
	punpckhbw xmmD,xmmG	; xmmD=(11 13 15 17 19 1B 1D 1F 21 23 25 27 29 2B 2D 2F)

	pxor      xmmH,xmmH

	movdqa    xmmC,xmmA
	punpcklbw xmmA,xmmH	; xmmA=(00 02 04 06 08 0A 0C 0E)
	punpckhbw xmmC,xmmH	; xmmC=(10 12 14 16 18 1A 1C 1E)

	movdqa    xmmB,xmmE
	punpcklbw xmmE,xmmH	; xmmE=(20 22 24 26 28 2A 2C 2E)
	punpckhbw xmmB,xmmH	; xmmB=(01 03 05 07 09 0B 0D 0F)

	movdqa    xmmF,xmmD
	punpcklbw xmmD,xmmH	; xmmD=(11 13 15 17 19 1B 1D 1F)
	punpckhbw xmmF,xmmH	; xmmF=(21 23 25 27 29 2B 2D 2F)

%else ; RGB_PIXELSIZE == 4 ; -----------

.column_ld1:
	test	cl, SIZEOF_XMMWORD/16
	jz	short .column_ld2
	sub	rcx, byte SIZEOF_XMMWORD/16
	movd	xmmA, XMM_DWORD [rsi+rcx*RGB_PIXELSIZE]
.column_ld2:
	test	cl, SIZEOF_XMMWORD/8
	jz	short .column_ld4
	sub	rcx, byte SIZEOF_XMMWORD/8
	movq	xmmE, XMM_MMWORD [rsi+rcx*RGB_PIXELSIZE]
	pslldq	xmmA, SIZEOF_MMWORD
	por	xmmA,xmmE
.column_ld4:
	test	cl, SIZEOF_XMMWORD/4
	jz	short .column_ld8
	sub	rcx, byte SIZEOF_XMMWORD/4
	movdqa	xmmE,xmmA
	movdqu	xmmA, XMMWORD [rsi+rcx*RGB_PIXELSIZE]
.column_ld8:
	test	cl, SIZEOF_XMMWORD/2
	mov	rcx, SIZEOF_XMMWORD
	jz	short .rgb_ycc_cnv
	movdqa	xmmF,xmmA
	movdqa	xmmH,xmmE
	movdqu	xmmA, XMMWORD [rsi+0*SIZEOF_XMMWORD]
	movdqu	xmmE, XMMWORD [rsi+1*SIZEOF_XMMWORD]
	jmp	short .rgb_ycc_cnv

.columnloop:
	movdqu	xmmA, XMMWORD [rsi+0*SIZEOF_XMMWORD]
	movdqu	xmmE, XMMWORD [rsi+1*SIZEOF_XMMWORD]
	movdqu	xmmF, XMMWORD [rsi+2*SIZEOF_XMMWORD]
	movdqu	xmmH, XMMWORD [rsi+3*SIZEOF_XMMWORD]

.rgb_ycc_cnv:
	; xmmA=(00 10 20 30 01 11 21 31 02 12 22 32 03 13 23 33)
	; xmmE=(04 14 24 34 05 15 25 35 06 16 26 36 07 17 27 37)
	; xmmF=(08 18 28 38 09 19 29 39 0A 1A 2A 3A 0B 1B 2B 3B)
	; xmmH=(0C 1C 2C 3C 0D 1D 2D 3D 0E 1E 2E 3E 0F 1F 2F 3F)

	movdqa    xmmD,xmmA
	punpcklbw xmmA,xmmE	; xmmA=(00 04 10 14 20 24 30 34 01 05 11 15 21 25 31 35)
	punpckhbw xmmD,xmmE	; xmmD=(02 06 12 16 22 26 32 36 03 07 13 17 23 27 33 37)

	movdqa    xmmC,xmmF
	punpcklbw xmmF,xmmH	; xmmF=(08 0C 18 1C 28 2C 38 3C 09 0D 19 1D 29 2D 39 3D)
	punpckhbw xmmC,xmmH	; xmmC=(0A 0E 1A 1E 2A 2E 3A 3E 0B 0F 1B 1F 2B 2F 3B 3F)

	movdqa    xmmB,xmmA
	punpcklwd xmmA,xmmF	; xmmA=(00 04 08 0C 10 14 18 1C 20 24 28 2C 30 34 38 3C)
	punpckhwd xmmB,xmmF	; xmmB=(01 05 09 0D 11 15 19 1D 21 25 29 2D 31 35 39 3D)

	movdqa    xmmG,xmmD
	punpcklwd xmmD,xmmC	; xmmD=(02 06 0A 0E 12 16 1A 1E 22 26 2A 2E 32 36 3A 3E)
	punpckhwd xmmG,xmmC	; xmmG=(03 07 0B 0F 13 17 1B 1F 23 27 2B 2F 33 37 3B 3F)

	movdqa    xmmE,xmmA
	punpcklbw xmmA,xmmD	; xmmA=(00 02 04 06 08 0A 0C 0E 10 12 14 16 18 1A 1C 1E)
	punpckhbw xmmE,xmmD	; xmmE=(20 22 24 26 28 2A 2C 2E 30 32 34 36 38 3A 3C 3E)

	movdqa    xmmH,xmmB
	punpcklbw xmmB,xmmG	; xmmB=(01 03 05 07 09 0B 0D 0F 11 13 15 17 19 1B 1D 1F)
	punpckhbw xmmH,xmmG	; xmmH=(21 23 25 27 29 2B 2D 2F 31 33 35 37 39 3B 3D 3F)

	pxor      xmmF,xmmF

	movdqa    xmmC,xmmA
	punpcklbw xmmA,xmmF	; xmmA=(00 02 04 06 08 0A 0C 0E)
	punpckhbw xmmC,xmmF	; xmmC=(10 12 14 16 18 1A 1C 1E)

	movdqa    xmmD,xmmB
	punpcklbw xmmB,xmmF	; xmmB=(01 03 05 07 09 0B 0D 0F)
	punpckhbw xmmD,xmmF	; xmmD=(11 13 15 17 19 1B 1D 1F)

	movdqa    xmmG,xmmE
	punpcklbw xmmE,xmmF	; xmmE=(20 22 24 26 28 2A 2C 2E)
	punpckhbw xmmG,xmmF	; xmmG=(30 32 34 36 38 3A 3C 3E)

	punpcklbw xmmF,xmmH
	punpckhbw xmmH,xmmH
	psrlw     xmmF,BYTE_BIT	; xmmF=(21 23 25 27 29 2B 2D 2F)
	psrlw     xmmH,BYTE_BIT	; xmmH=(31 33 35 37 39 3B 3D 3F)

%endif ; RGB_PIXELSIZE ; ---------------

	; xmm0=R(02468ACE)=RE, xmm2=G(02468ACE)=GE, xmm4=B(02468ACE)=BE
	; xmm1=R(13579BDF)=RO, xmm3=G(13579BDF)=GO, xmm5=B(13579BDF)=BO

	; (Original)
	; Y  =  0.29900 * R + 0.58700 * G + 0.11400 * B
	; Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + CENTERJSAMPLE
	; Cr =  0.50000 * R - 0.41869 * G - 0.08131 * B + CENTERJSAMPLE
	;
	; (This implementation)
	; Y  =  0.29900 * R + 0.33700 * G + 0.11400 * B + 0.25000 * G
	; Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + CENTERJSAMPLE
	; Cr =  0.50000 * R - 0.41869 * G - 0.08131 * B + CENTERJSAMPLE

	movdqa    XMMWORD [wk(0)], xmm0	; wk(0)=RE
	movdqa    XMMWORD [wk(1)], xmm1	; wk(1)=RO
	movdqa    XMMWORD [wk(2)], xmm4	; wk(2)=BE
	movdqa    XMMWORD [wk(3)], xmm5	; wk(3)=BO

	movdqa    xmm6,xmm1
	punpcklwd xmm1,xmm3
	punpckhwd xmm6,xmm3
	movdqa    xmm7,xmm1
	movdqa    xmm4,xmm6
	pmaddwd   xmm1,[rel PW_F0299_F0337] ; xmm1=ROL*FIX(0.299)+GOL*FIX(0.337)
	pmaddwd   xmm6,[rel PW_F0299_F0337] ; xmm6=ROH*FIX(0.299)+GOH*FIX(0.337)
	pmaddwd   xmm7,[rel PW_MF016_MF033] ; xmm7=ROL*-FIX(0.168)+GOL*-FIX(0.331)
	pmaddwd   xmm4,[rel PW_MF016_MF033] ; xmm4=ROH*-FIX(0.168)+GOH*-FIX(0.331)

	movdqa    XMMWORD [wk(4)], xmm1	; wk(4)=ROL*FIX(0.299)+GOL*FIX(0.337)
	movdqa    XMMWORD [wk(5)], xmm6	; wk(5)=ROH*FIX(0.299)+GOH*FIX(0.337)

	pxor      xmm1,xmm1
	pxor      xmm6,xmm6
	punpcklwd xmm1,xmm5		; xmm1=BOL
	punpckhwd xmm6,xmm5		; xmm6=BOH
	psrld     xmm1,1		; xmm1=BOL*FIX(0.500)
	psrld     xmm6,1		; xmm6=BOH*FIX(0.500)

	movdqa    xmm5,[rel PD_ONEHALFM1_CJ] ; xmm5=[PD_ONEHALFM1_CJ]

	paddd     xmm7,xmm1
	paddd     xmm4,xmm6
	paddd     xmm7,xmm5
	paddd     xmm4,xmm5
	psrld     xmm7,SCALEBITS	; xmm7=CbOL
	psrld     xmm4,SCALEBITS	; xmm4=CbOH
	packssdw  xmm7,xmm4		; xmm7=CbO

	movdqa    xmm1, XMMWORD [wk(2)]	; xmm1=BE

	movdqa    xmm6,xmm0
	punpcklwd xmm0,xmm2
	punpckhwd xmm6,xmm2
	movdqa    xmm5,xmm0
	movdqa    xmm4,xmm6
	pmaddwd   xmm0,[rel PW_F0299_F0337] ; xmm0=REL*FIX(0.299)+GEL*FIX(0.337)
	pmaddwd   xmm6,[rel PW_F0299_F0337] ; xmm6=REH*FIX(0.299)+GEH*FIX(0.337)
	pmaddwd   xmm5,[rel PW_MF016_MF033] ; xmm5=REL*-FIX(0.168)+GEL*-FIX(0.331)
	pmaddwd   xmm4,[rel PW_MF016_MF033] ; xmm4=REH*-FIX(0.168)+GEH*-FIX(0.331)

	movdqa    XMMWORD [wk(6)], xmm0	; wk(6)=REL*FIX(0.299)+GEL*FIX(0.337)
	movdqa    XMMWORD [wk(7)], xmm6	; wk(7)=REH*FIX(0.299)+GEH*FIX(0.337)

	pxor      xmm0,xmm0
	pxor      xmm6,xmm6
	punpcklwd xmm0,xmm1		; xmm0=BEL
	punpckhwd xmm6,xmm1		; xmm6=BEH
	psrld     xmm0,1		; xmm0=BEL*FIX(0.500)
	psrld     xmm6,1		; xmm6=BEH*FIX(0.500)

	movdqa    xmm1,[rel PD_ONEHALFM1_CJ] ; xmm1=[PD_ONEHALFM1_CJ]

	paddd     xmm5,xmm0
	paddd     xmm4,xmm6
	paddd     xmm5,xmm1
	paddd     xmm4,xmm1
	psrld     xmm5,SCALEBITS	; xmm5=CbEL
	psrld     xmm4,SCALEBITS	; xmm4=CbEH
	packssdw  xmm5,xmm4		; xmm5=CbE

	psllw     xmm7,BYTE_BIT
	por       xmm5,xmm7		; xmm5=Cb
	movdqa    XMMWORD [rbx], xmm5	; Save Cb

	movdqa    xmm0, XMMWORD [wk(3)]	; xmm0=BO
	movdqa    xmm6, XMMWORD [wk(2)]	; xmm6=BE
	movdqa    xmm1, XMMWORD [wk(1)]	; xmm1=RO

	movdqa    xmm4,xmm0
	punpcklwd xmm0,xmm3
	punpckhwd xmm4,xmm3
	movdqa    xmm7,xmm0
	movdqa    xmm5,xmm4
	pmaddwd   xmm0,[rel PW_F0114_F0250] ; xmm0=BOL*FIX(0.114)+GOL*FIX(0.250)
	pmaddwd   xmm4,[rel PW_F0114_F0250] ; xmm4=BOH*FIX(0.114)+GOH*FIX(0.250)
	pmaddwd   xmm7,[rel PW_MF008_MF041] ; xmm7=BOL*-FIX(0.081)+GOL*-FIX(0.418)
	pmaddwd   xmm5,[rel PW_MF008_MF041] ; xmm5=BOH*-FIX(0.081)+GOH*-FIX(0.418)

	movdqa    xmm3,[rel PD_ONEHALF]	; xmm3=[PD_ONEHALF]

	paddd     xmm0, XMMWORD [wk(4)]
	paddd     xmm4, XMMWORD [wk(5)]
	paddd     xmm0,xmm3
	paddd     xmm4,xmm3
	psrld     xmm0,SCALEBITS	; xmm0=YOL
	psrld     xmm4,SCALEBITS	; xmm4=YOH
	packssdw  xmm0,xmm4		; xmm0=YO

	pxor      xmm3,xmm3
	pxor      xmm4,xmm4
	punpcklwd xmm3,xmm1		; xmm3=ROL
	punpckhwd xmm4,xmm1		; xmm4=ROH
	psrld     xmm3,1		; xmm3=ROL*FIX(0.500)
	psrld     xmm4,1		; xmm4=ROH*FIX(0.500)

	movdqa    xmm1,[rel PD_ONEHALFM1_CJ] ; xmm1=[PD_ONEHALFM1_CJ]

	paddd     xmm7,xmm3
	paddd     xmm5,xmm4
	paddd     xmm7,xmm1
	paddd     xmm5,xmm1
	psrld     xmm7,SCALEBITS	; xmm7=CrOL
	psrld     xmm5,SCALEBITS	; xmm5=CrOH
	packssdw  xmm7,xmm5		; xmm7=CrO

	movdqa    xmm3, XMMWORD [wk(0)]	; xmm3=RE

	movdqa    xmm4,xmm6
	punpcklwd xmm6,xmm2
	punpckhwd xmm4,xmm2
	movdqa    xmm1,xmm6
	movdqa    xmm5,xmm4
	pmaddwd   xmm6,[rel PW_F0114_F0250] ; xmm6=BEL*FIX(0.114)+GEL*FIX(0.250)
	pmaddwd   xmm4,[rel PW_F0114_F0250] ; xmm4=BEH*FIX(0.114)+GEH*FIX(0.250)
	pmaddwd   xmm1,[rel PW_MF008_MF041] ; xmm1=BEL*-FIX(0.081)+GEL*-FIX(0.418)
	pmaddwd   xmm5,[rel PW_MF008_MF041] ; xmm5=BEH*-FIX(0.081)+GEH*-FIX(0.418)

	movdqa    xmm2,[rel PD_ONEHALF]	; xmm2=[PD_ONEHALF]

	paddd     xmm6, XMMWORD [wk(6)]
	paddd     xmm4, XMMWORD [wk(7)]
	paddd     xmm6,xmm2
	paddd     xmm4,xmm2
	psrld     xmm6,SCALEBITS	; xmm6=YEL
	psrld     xmm4,SCALEBITS	; xmm4=YEH
	packssdw  xmm6,xmm4		; xmm6=YE

	psllw     xmm0,BYTE_BIT
	por       xmm6,xmm0		; xmm6=Y
	movdqa    XMMWORD [rdi], xmm6	; Save Y

	pxor      xmm2,xmm2
	pxor      xmm4,xmm4
	punpcklwd xmm2,xmm3		; xmm2=REL
	punpckhwd xmm4,xmm3		; xmm4=REH
	psrld     xmm2,1		; xmm2=REL*FIX(0.500)
	psrld     xmm4,1		; xmm4=REH*FIX(0.500)

	movdqa    xmm0,[rel PD_ONEHALFM1_CJ] ; xmm0=[PD_ONEHALFM1_CJ]

	paddd     xmm1,xmm2
	paddd     xmm5,xmm4
	paddd     xmm1,xmm0
	paddd     xmm5,xmm0
	psrld     xmm1,SCALEBITS	; xmm1=CrEL
	psrld     xmm5,SCALEBITS	; xmm5=CrEH
	packssdw  xmm1,xmm5		; xmm1=CrE

	psllw     xmm7,BYTE_BIT
	por       xmm1,xmm7		; xmm1=Cr
	movdqa    XMMWORD [rdx], xmm1	; Save Cr

	sub	rcx, byte SIZEOF_XMMWORD
	add	rsi, byte RGB_PIXELSIZE*SIZEOF_XMMWORD	; inptr
	add	rdi, byte SIZEOF_XMMWORD		; outptr0
	add	rbx, byte SIZEOF_XMMWORD		; outptr1
	add	rdx, byte SIZEOF_XMMWORD		; outptr2
	cmp	rcx, byte SIZEOF_XMMWORD
	jae	near .columnloop
	test	rcx,rcx
	jnz	near .column_ld1

	pop	rcx			; col
	pop	rsi
	pop	rdi
	pop	rbx
	pop	rdx

	add	rsi, byte SIZEOF_JSAMPROW	; input_buf
	add	rdi, byte SIZEOF_JSAMPROW
	add	rbx, byte SIZEOF_JSAMPROW
	add	rdx, byte SIZEOF_JSAMPROW
	dec	rax				; num_rows
	jg	near .rowloop

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

; For some reason, the OS X linker does not honor the request to align the
; segment unless we do this.
	align	16