libavcodec/x86/dsputilenc_yasm.asm - third_party/ffmpeg - Git at Google

 ;*****************************************************************************
 ;* MMX optimized DSP utils
 ;*****************************************************************************
 ;* Copyright (c) 2000, 2001 Fabrice Bellard
 ;* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
 ;*
 ;* This file is part of FFmpeg.
 ;*
 ;* FFmpeg is free software; you can redistribute it and/or
 ;* modify it under the terms of the GNU Lesser General Public
 ;* License as published by the Free Software Foundation; either
 ;* version 2.1 of the License, or (at your option) any later version.
 ;*
 ;* FFmpeg is distributed in the hope that it will be useful,
 ;* but WITHOUT ANY WARRANTY; without even the implied warranty of
 ;* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 ;* Lesser General Public License for more details.
 ;*
 ;* You should have received a copy of the GNU Lesser General Public
 ;* License along with FFmpeg; if not, write to the Free Software
 ;* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 ;*****************************************************************************

 %include "libavutil/x86/x86inc.asm"
 %include "libavutil/x86/x86util.asm"

 SECTION .text

 %macro DIFF_PIXELS_1 4
     movh            %1, %3
     movh            %2, %4
     punpcklbw       %2, %1
     punpcklbw       %1, %1
     psubw           %1, %2
 %endmacro

 ; %1=uint8_t *pix1, %2=uint8_t *pix2, %3=static offset, %4=stride, %5=stride*3
 ; %6=temporary storage location
 ; this macro requires $mmsize stack space (aligned) on %6 (except on SSE+x86-64)
 %macro DIFF_PIXELS_8 6
     DIFF_PIXELS_1   m0, m7, [%1     +%3], [%2     +%3]
     DIFF_PIXELS_1   m1, m7, [%1+%4  +%3], [%2+%4  +%3]
     DIFF_PIXELS_1   m2, m7, [%1+%4*2+%3], [%2+%4*2+%3]
     add             %1, %5
     add             %2, %5
     DIFF_PIXELS_1   m3, m7, [%1     +%3], [%2     +%3]
     DIFF_PIXELS_1   m4, m7, [%1+%4  +%3], [%2+%4  +%3]
     DIFF_PIXELS_1   m5, m7, [%1+%4*2+%3], [%2+%4*2+%3]
     DIFF_PIXELS_1   m6, m7, [%1+%5  +%3], [%2+%5  +%3]
 %ifdef m8
     DIFF_PIXELS_1   m7, m8, [%1+%4*4+%3], [%2+%4*4+%3]
 %else
     mova          [%6], m0
     DIFF_PIXELS_1   m7, m0, [%1+%4*4+%3], [%2+%4*4+%3]
     mova            m0, [%6]
 %endif
     sub             %1, %5
     sub             %2, %5
 %endmacro

 %macro HADAMARD8 0
     SUMSUB_BADC       w, 0, 1, 2, 3
     SUMSUB_BADC       w, 4, 5, 6, 7
     SUMSUB_BADC       w, 0, 2, 1, 3
     SUMSUB_BADC       w, 4, 6, 5, 7
     SUMSUB_BADC       w, 0, 4, 1, 5
     SUMSUB_BADC       w, 2, 6, 3, 7
 %endmacro

 %macro ABS1_SUM 3
     ABS1            %1, %2
     paddusw         %3, %1
 %endmacro

 %macro ABS2_SUM 6
     ABS2            %1, %2, %3, %4
     paddusw         %5, %1
     paddusw         %6, %2
 %endmacro

 %macro ABS_SUM_8x8_64 1
     ABS2            m0, m1, m8, m9
     ABS2_SUM        m2, m3, m8, m9, m0, m1
     ABS2_SUM        m4, m5, m8, m9, m0, m1
     ABS2_SUM        m6, m7, m8, m9, m0, m1
     paddusw         m0, m1
 %endmacro

 %macro ABS_SUM_8x8_32 1
     mova          [%1], m7
     ABS1            m0, m7
     ABS1            m1, m7
     ABS1_SUM        m2, m7, m0
     ABS1_SUM        m3, m7, m1
     ABS1_SUM        m4, m7, m0
     ABS1_SUM        m5, m7, m1
     ABS1_SUM        m6, m7, m0
     mova            m2, [%1]
     ABS1_SUM        m2, m7, m1
     paddusw         m0, m1
 %endmacro

 ; FIXME: HSUM_* saturates at 64k, while an 8x8 hadamard or dct block can get up to
 ; about 100k on extreme inputs. But that's very unlikely to occur in natural video,
 ; and it's even more unlikely to not have any alternative mvs/modes with lower cost.
 %macro HSUM_MMX 3
     mova            %2, %1
     psrlq           %1, 32
     paddusw         %1, %2
     mova            %2, %1
     psrlq           %1, 16
     paddusw         %1, %2
     movd            %3, %1
 %endmacro

 %macro HSUM_MMX2 3
     pshufw          %2, %1, 0xE
     paddusw         %1, %2
     pshufw          %2, %1, 0x1
     paddusw         %1, %2
     movd            %3, %1
 %endmacro

 %macro HSUM_SSE2 3
     movhlps         %2, %1
     paddusw         %1, %2
     pshuflw         %2, %1, 0xE
     paddusw         %1, %2
     pshuflw         %2, %1, 0x1
     paddusw         %1, %2
     movd            %3, %1
 %endmacro

 %macro STORE4 5
     mova [%1+mmsize*0], %2
     mova [%1+mmsize*1], %3
     mova [%1+mmsize*2], %4
     mova [%1+mmsize*3], %5
 %endmacro

 %macro LOAD4 5
     mova            %2, [%1+mmsize*0]
     mova            %3, [%1+mmsize*1]
     mova            %4, [%1+mmsize*2]
     mova            %5, [%1+mmsize*3]
 %endmacro

 %macro hadamard8_16_wrapper 3
 cglobal hadamard8_diff_%1, 4, 4, %2
 %ifndef m8
     %assign pad %3*mmsize-(4+stack_offset&(mmsize-1))
     SUB            rsp, pad
 %endif
     call hadamard8x8_diff_%1
 %ifndef m8
     ADD            rsp, pad
 %endif
     RET

 cglobal hadamard8_diff16_%1, 5, 6, %2
 %ifndef m8
     %assign pad %3*mmsize-(4+stack_offset&(mmsize-1))
     SUB            rsp, pad
 %endif

     call hadamard8x8_diff_%1
     mov            r5d, eax

     add             r1, 8
     add             r2, 8
     call hadamard8x8_diff_%1
     add            r5d, eax

     cmp            r4d, 16
     jne .done

     lea             r1, [r1+r3*8-8]
     lea             r2, [r2+r3*8-8]
     call hadamard8x8_diff_%1
     add            r5d, eax

     add             r1, 8
     add             r2, 8
     call hadamard8x8_diff_%1
     add            r5d, eax

 .done
     mov            eax, r5d
 %ifndef m8
     ADD            rsp, pad
 %endif
     RET
 %endmacro

 %macro HADAMARD8_DIFF_MMX 1
 ALIGN 16
 ; int hadamard8_diff_##cpu(void *s, uint8_t *src1, uint8_t *src2,
 ;                          int stride, int h)
 ; r0 = void *s = unused, int h = unused (always 8)
 ; note how r1, r2 and r3 are not clobbered in this function, so 16x16
 ; can simply call this 2x2x (and that's why we access rsp+gprsize
 ; everywhere, which is rsp of calling func
 hadamard8x8_diff_%1:
     lea                          r0, [r3*3]

     ; first 4x8 pixels
     DIFF_PIXELS_8                r1, r2,  0, r3, r0, rsp+gprsize+0x60
     HADAMARD8
     mova         [rsp+gprsize+0x60], m7
     TRANSPOSE4x4W                 0,  1,  2,  3,  7
     STORE4              rsp+gprsize, m0, m1, m2, m3
     mova                         m7, [rsp+gprsize+0x60]
     TRANSPOSE4x4W                 4,  5,  6,  7,  0
     STORE4         rsp+gprsize+0x40, m4, m5, m6, m7

     ; second 4x8 pixels
     DIFF_PIXELS_8                r1, r2,  4, r3, r0, rsp+gprsize+0x60
     HADAMARD8
     mova         [rsp+gprsize+0x60], m7
     TRANSPOSE4x4W                 0,  1,  2,  3,  7
     STORE4         rsp+gprsize+0x20, m0, m1, m2, m3
     mova                         m7, [rsp+gprsize+0x60]
     TRANSPOSE4x4W                 4,  5,  6,  7,  0

     LOAD4          rsp+gprsize+0x40, m0, m1, m2, m3
     HADAMARD8
     ABS_SUM_8x8_32 rsp+gprsize+0x60
     mova         [rsp+gprsize+0x60], m0

     LOAD4          rsp+gprsize     , m0, m1, m2, m3
     LOAD4          rsp+gprsize+0x20, m4, m5, m6, m7
     HADAMARD8
     ABS_SUM_8x8_32 rsp+gprsize
     paddusw                      m0, [rsp+gprsize+0x60]

     HSUM                         m0, m1, eax
     and                         rax, 0xFFFF
     ret

 hadamard8_16_wrapper %1, 0, 14
 %endmacro

 %macro HADAMARD8_DIFF_SSE2 2
 hadamard8x8_diff_%1:
     lea                          r0, [r3*3]
     DIFF_PIXELS_8                r1, r2,  0, r3, r0, rsp+gprsize
     HADAMARD8
 %ifdef ARCH_X86_64
     TRANSPOSE8x8W                 0,  1,  2,  3,  4,  5,  6,  7,  8
 %else
     TRANSPOSE8x8W                 0,  1,  2,  3,  4,  5,  6,  7, [rsp+gprsize], [rsp+mmsize+gprsize]
 %endif
     HADAMARD8
     ABS_SUM_8x8         rsp+gprsize
     HSUM_SSE2                    m0, m1, eax
     and                         eax, 0xFFFF
     ret

 hadamard8_16_wrapper %1, %2, 3
 %endmacro

 INIT_MMX
 %define ABS1 ABS1_MMX
 %define HSUM HSUM_MMX
 HADAMARD8_DIFF_MMX mmx

 %define ABS1 ABS1_MMX2
 %define HSUM HSUM_MMX2
 HADAMARD8_DIFF_MMX mmx2

 INIT_XMM
 %define ABS2 ABS2_MMX2
 %ifdef ARCH_X86_64
 %define ABS_SUM_8x8 ABS_SUM_8x8_64
 %else
 %define ABS_SUM_8x8 ABS_SUM_8x8_32
 %endif
 HADAMARD8_DIFF_SSE2 sse2, 10

 %define ABS2        ABS2_SSSE3
 %define ABS_SUM_8x8 ABS_SUM_8x8_64
 HADAMARD8_DIFF_SSE2 ssse3, 9

 INIT_XMM
 ; sse16_sse2(void *v, uint8_t * pix1, uint8_t * pix2, int line_size, int h)
 cglobal sse16_sse2, 5, 5, 8
     shr      r4d, 1
     pxor      m0, m0         ; mm0 = 0
     pxor      m7, m7         ; mm7 holds the sum

 .next2lines ; FIXME why are these unaligned movs? pix1[] is aligned
     movu      m1, [r1   ]    ; mm1 = pix1[0][0-15]
     movu      m2, [r2   ]    ; mm2 = pix2[0][0-15]
     movu      m3, [r1+r3]    ; mm3 = pix1[1][0-15]
     movu      m4, [r2+r3]    ; mm4 = pix2[1][0-15]

     ; todo: mm1-mm2, mm3-mm4
     ; algo: subtract mm1 from mm2 with saturation and vice versa
     ;       OR the result to get the absolute difference
     mova      m5, m1
     mova      m6, m3
     psubusb   m1, m2
     psubusb   m3, m4
     psubusb   m2, m5
     psubusb   m4, m6

     por       m2, m1
     por       m4, m3

     ; now convert to 16-bit vectors so we can square them
     mova      m1, m2
     mova      m3, m4

     punpckhbw m2, m0
     punpckhbw m4, m0
     punpcklbw m1, m0         ; mm1 not spread over (mm1,mm2)
     punpcklbw m3, m0         ; mm4 not spread over (mm3,mm4)

     pmaddwd   m2, m2
     pmaddwd   m4, m4
     pmaddwd   m1, m1
     pmaddwd   m3, m3

     lea       r1, [r1+r3*2]  ; pix1 += 2*line_size
     lea       r2, [r2+r3*2]  ; pix2 += 2*line_size

     paddd     m1, m2
     paddd     m3, m4
     paddd     m7, m1
     paddd     m7, m3

     dec       r4
     jnz .next2lines

     mova      m1, m7
     psrldq    m7, 8          ; shift hi qword to lo
     paddd     m7, m1
     mova      m1, m7
     psrldq    m7, 4          ; shift hi dword to lo
     paddd     m7, m1
     movd     eax, m7         ; return value
     RET
	;*****************************************************************************
	;* MMX optimized DSP utils
	;*****************************************************************************
	;* Copyright (c) 2000, 2001 Fabrice Bellard
	;* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
	;*
	;* This file is part of FFmpeg.
	;*
	;* FFmpeg is free software; you can redistribute it and/or
	;* modify it under the terms of the GNU Lesser General Public
	;* License as published by the Free Software Foundation; either
	;* version 2.1 of the License, or (at your option) any later version.
	;*
	;* FFmpeg is distributed in the hope that it will be useful,
	;* but WITHOUT ANY WARRANTY; without even the implied warranty of
	;* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	;* Lesser General Public License for more details.
	;*
	;* You should have received a copy of the GNU Lesser General Public
	;* License along with FFmpeg; if not, write to the Free Software
	;* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	;*****************************************************************************

	%include "libavutil/x86/x86inc.asm"
	%include "libavutil/x86/x86util.asm"

	SECTION .text

	%macro DIFF_PIXELS_1 4
	movh %1, %3
	movh %2, %4
	punpcklbw %2, %1
	punpcklbw %1, %1
	psubw %1, %2
	%endmacro

	; %1=uint8_t pix1, %2=uint8_t pix2, %3=static offset, %4=stride, %5=stride*3
	; %6=temporary storage location
	; this macro requires $mmsize stack space (aligned) on %6 (except on SSE+x86-64)
	%macro DIFF_PIXELS_8 6
	DIFF_PIXELS_1 m0, m7, [%1 +%3], [%2 +%3]
	DIFF_PIXELS_1 m1, m7, [%1+%4 +%3], [%2+%4 +%3]
	DIFF_PIXELS_1 m2, m7, [%1+%42+%3], [%2+%42+%3]
	add %1, %5
	add %2, %5
	DIFF_PIXELS_1 m3, m7, [%1 +%3], [%2 +%3]
	DIFF_PIXELS_1 m4, m7, [%1+%4 +%3], [%2+%4 +%3]
	DIFF_PIXELS_1 m5, m7, [%1+%42+%3], [%2+%42+%3]
	DIFF_PIXELS_1 m6, m7, [%1+%5 +%3], [%2+%5 +%3]
	%ifdef m8
	DIFF_PIXELS_1 m7, m8, [%1+%44+%3], [%2+%44+%3]
	%else
	mova [%6], m0
	DIFF_PIXELS_1 m7, m0, [%1+%44+%3], [%2+%44+%3]
	mova m0, [%6]
	%endif
	sub %1, %5
	sub %2, %5
	%endmacro

	%macro HADAMARD8 0
	SUMSUB_BADC w, 0, 1, 2, 3
	SUMSUB_BADC w, 4, 5, 6, 7
	SUMSUB_BADC w, 0, 2, 1, 3
	SUMSUB_BADC w, 4, 6, 5, 7
	SUMSUB_BADC w, 0, 4, 1, 5
	SUMSUB_BADC w, 2, 6, 3, 7
	%endmacro

	%macro ABS1_SUM 3
	ABS1 %1, %2
	paddusw %3, %1
	%endmacro

	%macro ABS2_SUM 6
	ABS2 %1, %2, %3, %4
	paddusw %5, %1
	paddusw %6, %2
	%endmacro

	%macro ABS_SUM_8x8_64 1
	ABS2 m0, m1, m8, m9
	ABS2_SUM m2, m3, m8, m9, m0, m1
	ABS2_SUM m4, m5, m8, m9, m0, m1
	ABS2_SUM m6, m7, m8, m9, m0, m1
	paddusw m0, m1
	%endmacro

	%macro ABS_SUM_8x8_32 1
	mova [%1], m7
	ABS1 m0, m7
	ABS1 m1, m7
	ABS1_SUM m2, m7, m0
	ABS1_SUM m3, m7, m1
	ABS1_SUM m4, m7, m0
	ABS1_SUM m5, m7, m1
	ABS1_SUM m6, m7, m0
	mova m2, [%1]
	ABS1_SUM m2, m7, m1
	paddusw m0, m1
	%endmacro

	; FIXME: HSUM_* saturates at 64k, while an 8x8 hadamard or dct block can get up to
	; about 100k on extreme inputs. But that's very unlikely to occur in natural video,
	; and it's even more unlikely to not have any alternative mvs/modes with lower cost.
	%macro HSUM_MMX 3
	mova %2, %1
	psrlq %1, 32
	paddusw %1, %2
	mova %2, %1
	psrlq %1, 16
	paddusw %1, %2
	movd %3, %1
	%endmacro

	%macro HSUM_MMX2 3
	pshufw %2, %1, 0xE
	paddusw %1, %2
	pshufw %2, %1, 0x1
	paddusw %1, %2
	movd %3, %1
	%endmacro

	%macro HSUM_SSE2 3
	movhlps %2, %1
	paddusw %1, %2
	pshuflw %2, %1, 0xE
	paddusw %1, %2
	pshuflw %2, %1, 0x1
	paddusw %1, %2
	movd %3, %1
	%endmacro

	%macro STORE4 5
	mova [%1+mmsize*0], %2
	mova [%1+mmsize*1], %3
	mova [%1+mmsize*2], %4
	mova [%1+mmsize*3], %5
	%endmacro

	%macro LOAD4 5
	mova %2, [%1+mmsize*0]
	mova %3, [%1+mmsize*1]
	mova %4, [%1+mmsize*2]
	mova %5, [%1+mmsize*3]
	%endmacro

	%macro hadamard8_16_wrapper 3
	cglobal hadamard8_diff_%1, 4, 4, %2
	%ifndef m8
	%assign pad %3*mmsize-(4+stack_offset&(mmsize-1))
	SUB rsp, pad
	%endif
	call hadamard8x8_diff_%1
	%ifndef m8
	ADD rsp, pad
	%endif
	RET

	cglobal hadamard8_diff16_%1, 5, 6, %2
	%ifndef m8
	%assign pad %3*mmsize-(4+stack_offset&(mmsize-1))
	SUB rsp, pad
	%endif

	call hadamard8x8_diff_%1
	mov r5d, eax

	add r1, 8
	add r2, 8
	call hadamard8x8_diff_%1
	add r5d, eax

	cmp r4d, 16
	jne .done

	lea r1, [r1+r3*8-8]
	lea r2, [r2+r3*8-8]
	call hadamard8x8_diff_%1
	add r5d, eax

	add r1, 8
	add r2, 8
	call hadamard8x8_diff_%1
	add r5d, eax

	.done
	mov eax, r5d
	%ifndef m8
	ADD rsp, pad
	%endif
	RET
	%endmacro

	%macro HADAMARD8_DIFF_MMX 1
	ALIGN 16
	; int hadamard8_diff_##cpu(void s, uint8_t src1, uint8_t *src2,
	; int stride, int h)
	; r0 = void *s = unused, int h = unused (always 8)
	; note how r1, r2 and r3 are not clobbered in this function, so 16x16
	; can simply call this 2x2x (and that's why we access rsp+gprsize
	; everywhere, which is rsp of calling func
	hadamard8x8_diff_%1:
	lea r0, [r3*3]

	; first 4x8 pixels
	DIFF_PIXELS_8 r1, r2, 0, r3, r0, rsp+gprsize+0x60
	HADAMARD8
	mova [rsp+gprsize+0x60], m7
	TRANSPOSE4x4W 0, 1, 2, 3, 7
	STORE4 rsp+gprsize, m0, m1, m2, m3
	mova m7, [rsp+gprsize+0x60]
	TRANSPOSE4x4W 4, 5, 6, 7, 0
	STORE4 rsp+gprsize+0x40, m4, m5, m6, m7

	; second 4x8 pixels
	DIFF_PIXELS_8 r1, r2, 4, r3, r0, rsp+gprsize+0x60
	HADAMARD8
	mova [rsp+gprsize+0x60], m7
	TRANSPOSE4x4W 0, 1, 2, 3, 7
	STORE4 rsp+gprsize+0x20, m0, m1, m2, m3
	mova m7, [rsp+gprsize+0x60]
	TRANSPOSE4x4W 4, 5, 6, 7, 0

	LOAD4 rsp+gprsize+0x40, m0, m1, m2, m3
	HADAMARD8
	ABS_SUM_8x8_32 rsp+gprsize+0x60
	mova [rsp+gprsize+0x60], m0

	LOAD4 rsp+gprsize , m0, m1, m2, m3
	LOAD4 rsp+gprsize+0x20, m4, m5, m6, m7
	HADAMARD8
	ABS_SUM_8x8_32 rsp+gprsize
	paddusw m0, [rsp+gprsize+0x60]

	HSUM m0, m1, eax
	and rax, 0xFFFF
	ret

	hadamard8_16_wrapper %1, 0, 14
	%endmacro

	%macro HADAMARD8_DIFF_SSE2 2
	hadamard8x8_diff_%1:
	lea r0, [r3*3]
	DIFF_PIXELS_8 r1, r2, 0, r3, r0, rsp+gprsize
	HADAMARD8
	%ifdef ARCH_X86_64
	TRANSPOSE8x8W 0, 1, 2, 3, 4, 5, 6, 7, 8
	%else
	TRANSPOSE8x8W 0, 1, 2, 3, 4, 5, 6, 7, [rsp+gprsize], [rsp+mmsize+gprsize]
	%endif
	HADAMARD8
	ABS_SUM_8x8 rsp+gprsize
	HSUM_SSE2 m0, m1, eax
	and eax, 0xFFFF
	ret

	hadamard8_16_wrapper %1, %2, 3
	%endmacro

	INIT_MMX
	%define ABS1 ABS1_MMX
	%define HSUM HSUM_MMX
	HADAMARD8_DIFF_MMX mmx

	%define ABS1 ABS1_MMX2
	%define HSUM HSUM_MMX2
	HADAMARD8_DIFF_MMX mmx2

	INIT_XMM
	%define ABS2 ABS2_MMX2
	%ifdef ARCH_X86_64
	%define ABS_SUM_8x8 ABS_SUM_8x8_64
	%else
	%define ABS_SUM_8x8 ABS_SUM_8x8_32
	%endif
	HADAMARD8_DIFF_SSE2 sse2, 10

	%define ABS2 ABS2_SSSE3
	%define ABS_SUM_8x8 ABS_SUM_8x8_64
	HADAMARD8_DIFF_SSE2 ssse3, 9

	INIT_XMM
	; sse16_sse2(void v, uint8_t pix1, uint8_t * pix2, int line_size, int h)
	cglobal sse16_sse2, 5, 5, 8
	shr r4d, 1
	pxor m0, m0 ; mm0 = 0
	pxor m7, m7 ; mm7 holds the sum

	.next2lines ; FIXME why are these unaligned movs? pix1[] is aligned
	movu m1, [r1 ] ; mm1 = pix1[0][0-15]
	movu m2, [r2 ] ; mm2 = pix2[0][0-15]
	movu m3, [r1+r3] ; mm3 = pix1[1][0-15]
	movu m4, [r2+r3] ; mm4 = pix2[1][0-15]

	; todo: mm1-mm2, mm3-mm4
	; algo: subtract mm1 from mm2 with saturation and vice versa
	; OR the result to get the absolute difference
	mova m5, m1
	mova m6, m3
	psubusb m1, m2
	psubusb m3, m4
	psubusb m2, m5
	psubusb m4, m6

	por m2, m1
	por m4, m3

	; now convert to 16-bit vectors so we can square them
	mova m1, m2
	mova m3, m4

	punpckhbw m2, m0
	punpckhbw m4, m0
	punpcklbw m1, m0 ; mm1 not spread over (mm1,mm2)
	punpcklbw m3, m0 ; mm4 not spread over (mm3,mm4)

	pmaddwd m2, m2
	pmaddwd m4, m4
	pmaddwd m1, m1
	pmaddwd m3, m3

	lea r1, [r1+r32] ; pix1 += 2line_size
	lea r2, [r2+r32] ; pix2 += 2line_size

	paddd m1, m2
	paddd m3, m4
	paddd m7, m1
	paddd m7, m3

	dec r4
	jnz .next2lines

	mova m1, m7
	psrldq m7, 8 ; shift hi qword to lo
	paddd m7, m1
	mova m1, m7
	psrldq m7, 4 ; shift hi dword to lo
	paddd m7, m1
	movd eax, m7 ; return value
	RET