ffmpeg/libavcodec/i386/sad_mmx.s

799 lines
19 KiB
ArmAsm

; MMX/SSE optimized routines for SAD of 16*16 macroblocks
; Copyright (C) Juan J. Sierralta P. <juanjo@atmlab.utfsm.cl>
;
; dist1_* Original Copyright (C) 2000 Chris Atenasio <chris@crud.net>
; Enhancements and rest Copyright (C) 2000 Andrew Stevens <as@comlab.ox.ac.uk>
;
; This program is free software; you can redistribute it and/or
; modify it under the terms of the GNU General Public License
; as published by the Free Software Foundation; either version 2
; of the License, or (at your option) any later version.
;
; This program 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 General Public License for more details.
;
; You should have received a copy of the GNU General Public License
; along with this program; if not, write to the Free Software
; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
;
global pix_abs16x16_mmx
; int pix_abs16x16_mmx(unsigned char *pix1,unsigned char *pix2, int lx, int h);
; esi = p1 (init: blk1)
; edi = p2 (init: blk2)
; ecx = rowsleft (init: h)
; edx = lx;
; mm0 = distance accumulators (4 words)
; mm1 = distance accumulators (4 words)
; mm2 = temp
; mm3 = temp
; mm4 = temp
; mm5 = temp
; mm6 = 0
; mm7 = temp
align 32
pix_abs16x16_mmx:
push ebp ; save frame pointer
mov ebp, esp
push ebx ; Saves registers (called saves convention in
push ecx ; x86 GCC it seems)
push edx ;
push esi
push edi
pxor mm0, mm0 ; zero acculumators
pxor mm1, mm1
pxor mm6, mm6
mov esi, [ebp+8] ; get pix1
mov edi, [ebp+12] ; get pix2
mov edx, [ebp+16] ; get lx
mov ecx, [ebp+20] ; get rowsleft
jmp .nextrow
align 32
.nextrow:
; First 8 bytes of the row
movq mm4, [edi] ; load first 8 bytes of pix2 row
movq mm5, [esi] ; load first 8 bytes of pix1 row
movq mm3, mm4 ; mm4 := abs(mm4-mm5)
movq mm2,[esi+8] ; load last 8 bytes of pix1 row
psubusb mm4, mm5
movq mm7,[edi+8] ; load last 8 bytes of pix2 row
psubusb mm5, mm3
por mm4, mm5
; Last 8 bytes of the row
movq mm3, mm7 ; mm7 := abs(mm7-mm2)
psubusb mm7, mm2
psubusb mm2, mm3
por mm7, mm2
; Now mm4 and mm7 have 16 absdiffs to add
; First 8 bytes of the row2
add edi, edx
movq mm2, [edi] ; load first 8 bytes of pix2 row
add esi, edx
movq mm5, [esi] ; load first 8 bytes of pix1 row
movq mm3, mm2 ; mm2 := abs(mm2-mm5)
psubusb mm2, mm5
movq mm6,[esi+8] ; load last 8 bytes of pix1 row
psubusb mm5, mm3
por mm2, mm5
; Last 8 bytes of the row2
movq mm5,[edi+8] ; load last 8 bytes of pix2 row
movq mm3, mm5 ; mm5 := abs(mm5-mm6)
psubusb mm5, mm6
psubusb mm6, mm3
por mm5, mm6
; Now mm2, mm4, mm5, mm7 have 32 absdiffs
movq mm3, mm7
pxor mm6, mm6 ; Zero mm6
punpcklbw mm3, mm6 ; Unpack to words and add
punpckhbw mm7, mm6
paddusw mm7, mm3
movq mm3, mm5
punpcklbw mm3, mm6 ; Unpack to words and add
punpckhbw mm5, mm6
paddusw mm5, mm3
paddusw mm0, mm7 ; Add to the acumulator (mm0)
paddusw mm1, mm5 ; Add to the acumulator (mm1)
movq mm3, mm4
punpcklbw mm3, mm6 ; Unpack to words and add
punpckhbw mm4, mm6
movq mm5, mm2
paddusw mm4, mm3
punpcklbw mm5, mm6 ; Unpack to words and add
punpckhbw mm2, mm6
paddusw mm2, mm5
; Loop termination
add esi, edx ; update pointers to next row
paddusw mm0, mm4 ; Add to the acumulator (mm0)
add edi, edx
sub ecx,2
paddusw mm1, mm2 ; Add to the acumulator (mm1)
test ecx, ecx ; check rowsleft
jnz near .nextrow
paddusw mm0, mm1
movq mm2, mm0 ; Copy mm0 to mm2
psrlq mm2, 32
paddusw mm0, mm2 ; Add
movq mm3, mm0
psrlq mm3, 16
paddusw mm0, mm3
movd eax, mm0 ; Store return value
and eax, 0xffff
pop edi
pop esi
pop edx
pop ecx
pop ebx
pop ebp ; restore stack pointer
;emms ; clear mmx registers
ret ; return
global pix_abs16x16_sse
; int pix_abs16x16_mmx(unsigned char *pix1,unsigned char *pix2, int lx, int h);
; esi = p1 (init: blk1)
; edi = p2 (init: blk2)
; ecx = rowsleft (init: h)
; edx = lx;
; mm0 = distance accumulators (4 words)
; mm1 = distance accumulators (4 words)
; mm2 = temp
; mm3 = temp
; mm4 = temp
; mm5 = temp
; mm6 = temp
; mm7 = temp
align 32
pix_abs16x16_sse:
push ebp ; save frame pointer
mov ebp, esp
push ebx ; Saves registers (called saves convention in
push ecx ; x86 GCC it seems)
push edx ;
push esi
push edi
pxor mm0, mm0 ; zero acculumators
pxor mm1, mm1
mov esi, [ebp+8] ; get pix1
mov edi, [ebp+12] ; get pix2
mov edx, [ebp+16] ; get lx
mov ecx, [ebp+20] ; get rowsleft
jmp .next4row
align 32
.next4row:
; First row
movq mm4, [edi] ; load first 8 bytes of pix2 row
movq mm5, [edi+8] ; load last 8 bytes of pix2 row
psadbw mm4, [esi] ; SAD of first 8 bytes
psadbw mm5, [esi+8] ; SAD of last 8 bytes
paddw mm0, mm4 ; Add to acumulators
paddw mm1, mm5
; Second row
add edi, edx;
add esi, edx;
movq mm6, [edi] ; load first 8 bytes of pix2 row
movq mm7, [edi+8] ; load last 8 bytes of pix2 row
psadbw mm6, [esi] ; SAD of first 8 bytes
psadbw mm7, [esi+8] ; SAD of last 8 bytes
paddw mm0, mm6 ; Add to acumulators
paddw mm1, mm7
; Third row
add edi, edx;
add esi, edx;
movq mm4, [edi] ; load first 8 bytes of pix2 row
movq mm5, [edi+8] ; load last 8 bytes of pix2 row
psadbw mm4, [esi] ; SAD of first 8 bytes
psadbw mm5, [esi+8] ; SAD of last 8 bytes
paddw mm0, mm4 ; Add to acumulators
paddw mm1, mm5
; Fourth row
add edi, edx;
add esi, edx;
movq mm6, [edi] ; load first 8 bytes of pix2 row
movq mm7, [edi+8] ; load last 8 bytes of pix2 row
psadbw mm6, [esi] ; SAD of first 8 bytes
psadbw mm7, [esi+8] ; SAD of last 8 bytes
paddw mm0, mm6 ; Add to acumulators
paddw mm1, mm7
; Loop termination
add esi, edx ; update pointers to next row
add edi, edx
sub ecx,4
test ecx, ecx ; check rowsleft
jnz near .next4row
paddd mm0, mm1 ; Sum acumulators
movd eax, mm0 ; Store return value
pop edi
pop esi
pop edx
pop ecx
pop ebx
pop ebp ; restore stack pointer
;emms ; clear mmx registers
ret ; return
global pix_abs16x16_x2_mmx
; int pix_abs16x16_x2_mmx(unsigned char *pix1,unsigned char *pix2, int lx, int h);
; esi = p1 (init: blk1)
; edi = p2 (init: blk2)
; ecx = rowsleft (init: h)
; edx = lx;
; mm0 = distance accumulators (4 words)
; mm1 = distance accumulators (4 words)
; mm2 = temp
; mm3 = temp
; mm4 = temp
; mm5 = temp
; mm6 = 0
; mm7 = temp
align 32
pix_abs16x16_x2_mmx:
push ebp ; save frame pointer
mov ebp, esp
push ebx ; Saves registers (called saves convention in
push ecx ; x86 GCC it seems)
push edx ;
push esi
push edi
pxor mm0, mm0 ; zero acculumators
pxor mm1, mm1
pxor mm6, mm6
mov esi, [ebp+8] ; get pix1
mov edi, [ebp+12] ; get pix2
mov edx, [ebp+16] ; get lx
mov ecx, [ebp+20] ; get rowsleft
jmp .nextrow_x2
align 32
.nextrow_x2:
; First 8 bytes of the row
movq mm4, [edi] ; load first 8 bytes of pix2 row
movq mm5, [edi+1] ; load bytes 1-8 of pix2 row
movq mm2, mm4 ; copy mm4 on mm2
movq mm3, mm5 ; copy mm5 on mm3
punpcklbw mm4, mm6 ; first 4 bytes of [edi] on mm4
punpcklbw mm5, mm6 ; first 4 bytes of [edi+1] on mm5
paddusw mm4, mm5 ; mm4 := first 4 bytes interpolated in words
psrlw mm4, 1
punpckhbw mm2, mm6 ; last 4 bytes of [edi] on mm2
punpckhbw mm3, mm6 ; last 4 bytes of [edi+1] on mm3
paddusw mm2, mm3 ; mm2 := last 4 bytes interpolated in words
psrlw mm2, 1
packuswb mm4, mm2 ; pack 8 bytes interpolated on mm4
movq mm5,[esi] ; load first 8 bytes of pix1 row
movq mm3, mm4 ; mm4 := abs(mm4-mm5)
psubusb mm4, mm5
psubusb mm5, mm3
por mm4, mm5
; Last 8 bytes of the row
movq mm7, [edi+8] ; load last 8 bytes of pix2 row
movq mm5, [edi+9] ; load bytes 10-17 of pix2 row
movq mm2, mm7 ; copy mm7 on mm2
movq mm3, mm5 ; copy mm5 on mm3
punpcklbw mm7, mm6 ; first 4 bytes of [edi+8] on mm7
punpcklbw mm5, mm6 ; first 4 bytes of [edi+9] on mm5
paddusw mm7, mm5 ; mm1 := first 4 bytes interpolated in words
psrlw mm7, 1
punpckhbw mm2, mm6 ; last 4 bytes of [edi] on mm2
punpckhbw mm3, mm6 ; last 4 bytes of [edi+1] on mm3
paddusw mm2, mm3 ; mm2 := last 4 bytes interpolated in words
psrlw mm2, 1
packuswb mm7, mm2 ; pack 8 bytes interpolated on mm1
movq mm5,[esi+8] ; load last 8 bytes of pix1 row
movq mm3, mm7 ; mm7 := abs(mm1-mm5)
psubusb mm7, mm5
psubusb mm5, mm3
por mm7, mm5
; Now mm4 and mm7 have 16 absdiffs to add
movq mm3, mm4 ; Make copies of these bytes
movq mm2, mm7
punpcklbw mm4, mm6 ; Unpack to words and add
punpcklbw mm7, mm6
paddusw mm4, mm7
paddusw mm0, mm4 ; Add to the acumulator (mm0)
punpckhbw mm3, mm6 ; Unpack to words and add
punpckhbw mm2, mm6
paddusw mm3, mm2
paddusw mm1, mm3 ; Add to the acumulator (mm1)
; Loop termination
add esi, edx ; update pointers to next row
add edi, edx
sub ecx,1
test ecx, ecx ; check rowsleft
jnz near .nextrow_x2
paddusw mm0, mm1
movq mm1, mm0 ; Copy mm0 to mm1
psrlq mm1, 32
paddusw mm0, mm1 ; Add
movq mm2, mm0
psrlq mm2, 16
paddusw mm0, mm2
movd eax, mm0 ; Store return value
and eax, 0xffff
pop edi
pop esi
pop edx
pop ecx
pop ebx
pop ebp ; restore stack pointer
emms ; clear mmx registers
ret ; return
global pix_abs16x16_y2_mmx
; int pix_abs16x16_y2_mmx(unsigned char *pix1,unsigned char *pix2, int lx, int h);
; esi = p1 (init: blk1)
; edi = p2 (init: blk2)
; ebx = p2 + lx
; ecx = rowsleft (init: h)
; edx = lx;
; mm0 = distance accumulators (4 words)
; mm1 = distance accumulators (4 words)
; mm2 = temp
; mm3 = temp
; mm4 = temp
; mm5 = temp
; mm6 = 0
; mm7 = temp
align 32
pix_abs16x16_y2_mmx:
push ebp ; save frame pointer
mov ebp, esp
push ebx ; Saves registers (called saves convention in
push ecx ; x86 GCC it seems)
push edx ;
push esi
push edi
pxor mm0, mm0 ; zero acculumators
pxor mm1, mm1
pxor mm6, mm6
mov esi, [ebp+8] ; get pix1
mov edi, [ebp+12] ; get pix2
mov edx, [ebp+16] ; get lx
mov ecx, [ebp+20] ; get rowsleft
mov ebx, edi
add ebx, edx
jmp .nextrow_y2
align 32
.nextrow_y2:
; First 8 bytes of the row
movq mm4, [edi] ; load first 8 bytes of pix2 row
movq mm5, [ebx] ; load bytes 1-8 of pix2 row
movq mm2, mm4 ; copy mm4 on mm2
movq mm3, mm5 ; copy mm5 on mm3
punpcklbw mm4, mm6 ; first 4 bytes of [edi] on mm4
punpcklbw mm5, mm6 ; first 4 bytes of [ebx] on mm5
paddusw mm4, mm5 ; mm4 := first 4 bytes interpolated in words
psrlw mm4, 1
punpckhbw mm2, mm6 ; last 4 bytes of [edi] on mm2
punpckhbw mm3, mm6 ; last 4 bytes of [edi+1] on mm3
paddusw mm2, mm3 ; mm2 := last 4 bytes interpolated in words
psrlw mm2, 1
packuswb mm4, mm2 ; pack 8 bytes interpolated on mm4
movq mm5,[esi] ; load first 8 bytes of pix1 row
movq mm3, mm4 ; mm4 := abs(mm4-mm5)
psubusb mm4, mm5
psubusb mm5, mm3
por mm4, mm5
; Last 8 bytes of the row
movq mm7, [edi+8] ; load last 8 bytes of pix2 row
movq mm5, [ebx+8] ; load bytes 10-17 of pix2 row
movq mm2, mm7 ; copy mm7 on mm2
movq mm3, mm5 ; copy mm5 on mm3
punpcklbw mm7, mm6 ; first 4 bytes of [edi+8] on mm7
punpcklbw mm5, mm6 ; first 4 bytes of [ebx+8] on mm5
paddusw mm7, mm5 ; mm1 := first 4 bytes interpolated in words
psrlw mm7, 1
punpckhbw mm2, mm6 ; last 4 bytes of [edi+8] on mm2
punpckhbw mm3, mm6 ; last 4 bytes of [ebx+8] on mm3
paddusw mm2, mm3 ; mm2 := last 4 bytes interpolated in words
psrlw mm2, 1
packuswb mm7, mm2 ; pack 8 bytes interpolated on mm1
movq mm5,[esi+8] ; load last 8 bytes of pix1 row
movq mm3, mm7 ; mm7 := abs(mm1-mm5)
psubusb mm7, mm5
psubusb mm5, mm3
por mm7, mm5
; Now mm4 and mm7 have 16 absdiffs to add
movq mm3, mm4 ; Make copies of these bytes
movq mm2, mm7
punpcklbw mm4, mm6 ; Unpack to words and add
punpcklbw mm7, mm6
paddusw mm4, mm7
paddusw mm0, mm4 ; Add to the acumulator (mm0)
punpckhbw mm3, mm6 ; Unpack to words and add
punpckhbw mm2, mm6
paddusw mm3, mm2
paddusw mm1, mm3 ; Add to the acumulator (mm1)
; Loop termination
add esi, edx ; update pointers to next row
add edi, edx
add ebx, edx
sub ecx,1
test ecx, ecx ; check rowsleft
jnz near .nextrow_y2
paddusw mm0, mm1
movq mm1, mm0 ; Copy mm0 to mm1
psrlq mm1, 32
paddusw mm0, mm1 ; Add
movq mm2, mm0
psrlq mm2, 16
paddusw mm0, mm2
movd eax, mm0 ; Store return value
and eax, 0xffff
pop edi
pop esi
pop edx
pop ecx
pop ebx
pop ebp ; restore stack pointer
emms ; clear mmx registers
ret ; return
global pix_abs16x16_xy2_mmx
; int pix_abs16x16_xy2_mmx(unsigned char *p1,unsigned char *p2,int lx,int h);
; esi = p1 (init: blk1)
; edi = p2 (init: blk2)
; ebx = p1+lx
; ecx = rowsleft (init: h)
; edx = lx;
; mm0 = distance accumulators (4 words)
; mm1 = bytes p2
; mm2 = bytes p1
; mm3 = bytes p1+lx
; I'd love to find someplace to stash p1+1 and p1+lx+1's bytes
; but I don't think thats going to happen in iA32-land...
; mm4 = temp 4 bytes in words interpolating p1, p1+1
; mm5 = temp 4 bytes in words from p2
; mm6 = temp comparison bit mask p1,p2
; mm7 = temp comparison bit mask p2,p1
align 32
pix_abs16x16_xy2_mmx:
push ebp ; save stack pointer
mov ebp, esp ; so that we can do this
push ebx ; Saves registers (called saves convention in
push ecx ; x86 GCC it seems)
push edx ;
push esi
push edi
pxor mm0, mm0 ; zero acculumators
mov esi, [ebp+12] ; get p1
mov edi, [ebp+8] ; get p2
mov edx, [ebp+16] ; get lx
mov ecx, [ebp+20] ; rowsleft := h
mov ebx, esi
add ebx, edx
jmp .nextrowmm11 ; snap to it
align 32
.nextrowmm11:
;;
;; First 8 bytes of row
;;
;; First 4 bytes of 8
movq mm4, [esi] ; mm4 := first 4 bytes p1
pxor mm7, mm7
movq mm2, mm4 ; mm2 records all 8 bytes
punpcklbw mm4, mm7 ; First 4 bytes p1 in Words...
movq mm6, [ebx] ; mm6 := first 4 bytes p1+lx
movq mm3, mm6 ; mm3 records all 8 bytes
punpcklbw mm6, mm7
paddw mm4, mm6
movq mm5, [esi+1] ; mm5 := first 4 bytes p1+1
punpcklbw mm5, mm7 ; First 4 bytes p1 in Words...
paddw mm4, mm5
movq mm6, [ebx+1] ; mm6 := first 4 bytes p1+lx+1
punpcklbw mm6, mm7
paddw mm4, mm6
psrlw mm4, 2 ; mm4 := First 4 bytes interpolated in words
movq mm5, [edi] ; mm5:=first 4 bytes of p2 in words
movq mm1, mm5
punpcklbw mm5, mm7
movq mm7,mm4
pcmpgtw mm7,mm5 ; mm7 := [i : W0..3,mm4>mm5]
movq mm6,mm4 ; mm6 := [i : W0..3, (mm4-mm5)*(mm4-mm5 > 0)]
psubw mm6,mm5
pand mm6, mm7
paddw mm0, mm6 ; Add to accumulator
movq mm6,mm5 ; mm6 := [i : W0..3,mm5>mm4]
pcmpgtw mm6,mm4
psubw mm5,mm4 ; mm5 := [i : B0..7, (mm5-mm4)*(mm5-mm4 > 0)]
pand mm5, mm6
paddw mm0, mm5 ; Add to accumulator
;; Second 4 bytes of 8
movq mm4, mm2 ; mm4 := Second 4 bytes p1 in words
pxor mm7, mm7
punpckhbw mm4, mm7
movq mm6, mm3 ; mm6 := Second 4 bytes p1+1 in words
punpckhbw mm6, mm7
paddw mm4, mm6
movq mm5, [esi+1] ; mm5 := first 4 bytes p1+1
punpckhbw mm5, mm7 ; First 4 bytes p1 in Words...
paddw mm4, mm5
movq mm6, [ebx+1] ; mm6 := first 4 bytes p1+lx+1
punpckhbw mm6, mm7
paddw mm4, mm6
psrlw mm4, 2 ; mm4 := First 4 bytes interpolated in words
movq mm5, mm1 ; mm5:= second 4 bytes of p2 in words
punpckhbw mm5, mm7
movq mm7,mm4
pcmpgtw mm7,mm5 ; mm7 := [i : W0..3,mm4>mm5]
movq mm6,mm4 ; mm6 := [i : W0..3, (mm4-mm5)*(mm4-mm5 > 0)]
psubw mm6,mm5
pand mm6, mm7
paddw mm0, mm6 ; Add to accumulator
movq mm6,mm5 ; mm6 := [i : W0..3,mm5>mm4]
pcmpgtw mm6,mm4
psubw mm5,mm4 ; mm5 := [i : B0..7, (mm5-mm4)*(mm5-mm4 > 0)]
pand mm5, mm6
paddw mm0, mm5 ; Add to accumulator
;;
;; Second 8 bytes of row
;;
;; First 4 bytes of 8
movq mm4, [esi+8] ; mm4 := first 4 bytes p1+8
pxor mm7, mm7
movq mm2, mm4 ; mm2 records all 8 bytes
punpcklbw mm4, mm7 ; First 4 bytes p1 in Words...
movq mm6, [ebx+8] ; mm6 := first 4 bytes p1+lx+8
movq mm3, mm6 ; mm3 records all 8 bytes
punpcklbw mm6, mm7
paddw mm4, mm6
movq mm5, [esi+9] ; mm5 := first 4 bytes p1+9
punpcklbw mm5, mm7 ; First 4 bytes p1 in Words...
paddw mm4, mm5
movq mm6, [ebx+9] ; mm6 := first 4 bytes p1+lx+9
punpcklbw mm6, mm7
paddw mm4, mm6
psrlw mm4, 2 ; mm4 := First 4 bytes interpolated in words
movq mm5, [edi+8] ; mm5:=first 4 bytes of p2+8 in words
movq mm1, mm5
punpcklbw mm5, mm7
movq mm7,mm4
pcmpgtw mm7,mm5 ; mm7 := [i : W0..3,mm4>mm5]
movq mm6,mm4 ; mm6 := [i : W0..3, (mm4-mm5)*(mm4-mm5 > 0)]
psubw mm6,mm5
pand mm6, mm7
paddw mm0, mm6 ; Add to accumulator
movq mm6,mm5 ; mm6 := [i : W0..3,mm5>mm4]
pcmpgtw mm6,mm4
psubw mm5,mm4 ; mm5 := [i : B0..7, (mm5-mm4)*(mm5-mm4 > 0)]
pand mm5, mm6
paddw mm0, mm5 ; Add to accumulator
;; Second 4 bytes of 8
movq mm4, mm2 ; mm4 := Second 4 bytes p1 in words
pxor mm7, mm7
punpckhbw mm4, mm7
movq mm6, mm3 ; mm6 := Second 4 bytes p1+1 in words
punpckhbw mm6, mm7
paddw mm4, mm6
movq mm5, [esi+9] ; mm5 := first 4 bytes p1+1
punpckhbw mm5, mm7 ; First 4 bytes p1 in Words...
paddw mm4, mm5
movq mm6, [ebx+9] ; mm6 := first 4 bytes p1+lx+1
punpckhbw mm6, mm7
paddw mm4, mm6
psrlw mm4, 2 ; mm4 := First 4 bytes interpolated in words
movq mm5, mm1 ; mm5:= second 4 bytes of p2 in words
punpckhbw mm5, mm7
movq mm7,mm4
pcmpgtw mm7,mm5 ; mm7 := [i : W0..3,mm4>mm5]
movq mm6,mm4 ; mm6 := [i : W0..3, (mm4-mm5)*(mm4-mm5 > 0)]
psubw mm6,mm5
pand mm6, mm7
paddw mm0, mm6 ; Add to accumulator
movq mm6,mm5 ; mm6 := [i : W0..3,mm5>mm4]
pcmpgtw mm6,mm4
psubw mm5,mm4 ; mm5 := [i : B0..7, (mm5-mm4)*(mm5-mm4 > 0)]
pand mm5, mm6
paddw mm0, mm5 ; Add to accumulator
;;
;; Loop termination condition... and stepping
;;
add esi, edx ; update pointer to next row
add edi, edx ; ditto
add ebx, edx
sub ecx,1
test ecx, ecx ; check rowsleft
jnz near .nextrowmm11
;; Sum the Accumulators
movq mm4, mm0
psrlq mm4, 32
paddw mm0, mm4
movq mm6, mm0
psrlq mm6, 16
paddw mm0, mm6
movd eax, mm0 ; store return value
and eax, 0xffff
pop edi
pop esi
pop edx
pop ecx
pop ebx
pop ebp ; restore stack pointer
emms ; clear mmx registers
ret ; we now return you to your regular programming