summaryrefslogtreecommitdiff
path: root/libavcodec/x86/videodsp.asm
blob: 34f007f8d23cc9529d63e309e108ff438b16300e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
;******************************************************************************
;* Core video DSP functions
;* Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com>
;*
;* This file is part of Libav.
;*
;* Libav 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.
;*
;* Libav 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 Libav; if not, write to the Free Software
;* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
;******************************************************************************

%include "libavutil/x86/x86util.asm"

SECTION .text

; void ff_emu_edge_core(uint8_t *buf, const uint8_t *src, x86_reg linesize,
;                       x86_reg start_y, x86_reg end_y, x86_reg block_h,
;                       x86_reg start_x, x86_reg end_x, x86_reg block_w);
;
; The actual function itself is below. It basically wraps a very simple
; w = end_x - start_x
; if (w) {
;   if (w > 22) {
;     jump to the slow loop functions
;   } else {
;     jump to the fast loop functions
;   }
; }
;
; ... and then the same for left/right extend also. See below for loop
; function implementations. Fast are fixed-width, slow is variable-width

%macro EMU_EDGE_FUNC 0
%if ARCH_X86_64
%define w_reg r7
cglobal emu_edge_core, 6, 9, 1
    mov         r8, r5          ; save block_h
%else
%define w_reg r6
cglobal emu_edge_core, 2, 7, 0
    mov         r4, r4m         ; end_y
    mov         r5, r5m         ; block_h
%endif

    ; start with vertical extend (top/bottom) and body pixel copy
    mov      w_reg, r7m
    sub      w_reg, r6m         ; w = start_x - end_x
    sub         r5, r4
%if ARCH_X86_64
    sub         r4, r3
%else
    sub         r4, dword r3m
%endif
    cmp      w_reg, 22
    jg .slow_v_extend_loop
%if ARCH_X86_32
    mov         r2, r2m         ; linesize
%endif
    sal      w_reg, 7           ; w * 128
%ifdef PIC
    lea        rax, [.emuedge_v_extend_1 - (.emuedge_v_extend_2 - .emuedge_v_extend_1)]
    add      w_reg, rax
%else
    lea      w_reg, [.emuedge_v_extend_1 - (.emuedge_v_extend_2 - .emuedge_v_extend_1)+w_reg]
%endif
    call     w_reg              ; fast top extend, body copy and bottom extend
.v_extend_end:

    ; horizontal extend (left/right)
    mov      w_reg, r6m         ; start_x
    sub         r0, w_reg
%if ARCH_X86_64
    mov         r3, r0          ; backup of buf+block_h*linesize
    mov         r5, r8
%else
    mov        r0m, r0          ; backup of buf+block_h*linesize
    mov         r5, r5m
%endif
    test     w_reg, w_reg
    jz .right_extend
    cmp      w_reg, 22
    jg .slow_left_extend_loop
    mov         r1, w_reg
    dec      w_reg
    ; FIXME we can do a if size == 1 here if that makes any speed difference, test me
    sar      w_reg, 1
    sal      w_reg, 6
    ; r0=buf+block_h*linesize,r7(64)/r6(32)=start_x offset for funcs
    ; r6(rax)/r3(ebx)=val,r2=linesize,r1=start_x,r5=block_h
%ifdef PIC
    lea        rax, [.emuedge_extend_left_2]
    add      w_reg, rax
%else
    lea      w_reg, [.emuedge_extend_left_2+w_reg]
%endif
    call     w_reg

    ; now r3(64)/r0(32)=buf,r2=linesize,r8/r5=block_h,r6/r3=val, r7/r6=end_x, r1=block_w
.right_extend:
%if ARCH_X86_32
    mov         r0, r0m
    mov         r5, r5m
%endif
    mov      w_reg, r7m         ; end_x
    mov         r1, r8m         ; block_w
    mov         r4, r1
    sub         r1, w_reg
    jz .h_extend_end            ; if (end_x == block_w) goto h_extend_end
    cmp         r1, 22
    jg .slow_right_extend_loop
    dec         r1
    ; FIXME we can do a if size == 1 here if that makes any speed difference, test me
    sar         r1, 1
    sal         r1, 6
%ifdef PIC
    lea        rax, [.emuedge_extend_right_2]
    add         r1, rax
%else
    lea         r1, [.emuedge_extend_right_2+r1]
%endif
    call        r1
.h_extend_end:
    RET

%if ARCH_X86_64
%define vall  al
%define valh  ah
%define valw  ax
%define valw2 r7w
%define valw3 r3w
%if WIN64
%define valw4 r7w
%else ; unix64
%define valw4 r3w
%endif
%define vald eax
%else
%define vall  bl
%define valh  bh
%define valw  bx
%define valw2 r6w
%define valw3 valw2
%define valw4 valw3
%define vald ebx
%define stack_offset 0x14
%endif

%endmacro

; macro to read/write a horizontal number of pixels (%2) to/from registers
; on x86-64, - fills xmm0-15 for consecutive sets of 16 pixels
;            - if (%2 & 15 == 8) fills the last 8 bytes into rax
;            - else if (%2 & 8)  fills 8 bytes into mm0
;            - if (%2 & 7 == 4)  fills the last 4 bytes into rax
;            - else if (%2 & 4)  fills 4 bytes into mm0-1
;            - if (%2 & 3 == 3)  fills 2 bytes into r7/r3, and 1 into eax
;              (note that we're using r3 for body/bottom because it's a shorter
;               opcode, and then the loop fits in 128 bytes)
;            - else              fills remaining bytes into rax
; on x86-32, - fills mm0-7 for consecutive sets of 8 pixels
;            - if (%2 & 7 == 4)  fills 4 bytes into ebx
;            - else if (%2 & 4)  fills 4 bytes into mm0-7
;            - if (%2 & 3 == 3)  fills 2 bytes into r6, and 1 into ebx
;            - else              fills remaining bytes into ebx
; writing data out is in the same way
%macro READ_NUM_BYTES 2
%assign %%src_off 0 ; offset in source buffer
%assign %%smidx   0 ; mmx register idx
%assign %%sxidx   0 ; xmm register idx

%if cpuflag(sse)
%rep %2/16
    movups xmm %+ %%sxidx, [r1+%%src_off]
%assign %%src_off %%src_off+16
%assign %%sxidx   %%sxidx+1
%endrep ; %2/16
%endif

%if ARCH_X86_64
%if (%2-%%src_off) == 8
    mov           rax, [r1+%%src_off]
%assign %%src_off %%src_off+8
%endif ; (%2-%%src_off) == 8
%endif ; x86-64

%rep (%2-%%src_off)/8
    movq    mm %+ %%smidx, [r1+%%src_off]
%assign %%src_off %%src_off+8
%assign %%smidx   %%smidx+1
%endrep ; (%2-%%dst_off)/8

%if (%2-%%src_off) == 4
    mov          vald, [r1+%%src_off]
%elif (%2-%%src_off) & 4
    movd    mm %+ %%smidx, [r1+%%src_off]
%assign %%src_off %%src_off+4
%endif ; (%2-%%src_off) ==/& 4

%if (%2-%%src_off) == 1
    mov          vall, [r1+%%src_off]
%elif (%2-%%src_off) == 2
    mov          valw, [r1+%%src_off]
%elif (%2-%%src_off) == 3
%ifidn %1, top
    mov         valw2, [r1+%%src_off]
%elifidn %1, body
    mov         valw3, [r1+%%src_off]
%elifidn %1, bottom
    mov         valw4, [r1+%%src_off]
%endif ; %1 ==/!= top
    mov          vall, [r1+%%src_off+2]
%endif ; (%2-%%src_off) == 1/2/3
%endmacro ; READ_NUM_BYTES

%macro WRITE_NUM_BYTES 2
%assign %%dst_off 0 ; offset in destination buffer
%assign %%dmidx   0 ; mmx register idx
%assign %%dxidx   0 ; xmm register idx

%if cpuflag(sse)
%rep %2/16
    movups [r0+%%dst_off], xmm %+ %%dxidx
%assign %%dst_off %%dst_off+16
%assign %%dxidx   %%dxidx+1
%endrep ; %2/16
%endif

%if ARCH_X86_64
%if (%2-%%dst_off) == 8
    mov    [r0+%%dst_off], rax
%assign %%dst_off %%dst_off+8
%endif ; (%2-%%dst_off) == 8
%endif ; x86-64

%rep (%2-%%dst_off)/8
    movq   [r0+%%dst_off], mm %+ %%dmidx
%assign %%dst_off %%dst_off+8
%assign %%dmidx   %%dmidx+1
%endrep ; (%2-%%dst_off)/8

%if (%2-%%dst_off) == 4
    mov    [r0+%%dst_off], vald
%elif (%2-%%dst_off) & 4
    movd   [r0+%%dst_off], mm %+ %%dmidx
%assign %%dst_off %%dst_off+4
%endif ; (%2-%%dst_off) ==/& 4

%if (%2-%%dst_off) == 1
    mov    [r0+%%dst_off], vall
%elif (%2-%%dst_off) == 2
    mov    [r0+%%dst_off], valw
%elif (%2-%%dst_off) == 3
%ifidn %1, top
    mov    [r0+%%dst_off], valw2
%elifidn %1, body
    mov    [r0+%%dst_off], valw3
%elifidn %1, bottom
    mov    [r0+%%dst_off], valw4
%endif ; %1 ==/!= top
    mov  [r0+%%dst_off+2], vall
%endif ; (%2-%%dst_off) == 1/2/3
%endmacro ; WRITE_NUM_BYTES

; vertical top/bottom extend and body copy fast loops
; these are function pointers to set-width line copy functions, i.e.
; they read a fixed number of pixels into set registers, and write
; those out into the destination buffer
; r0=buf,r1=src,r2=linesize,r3(64)/r3m(32)=start_x,r4=end_y,r5=block_h
; r6(eax/64)/r3(ebx/32)=val_reg
%macro VERTICAL_EXTEND 0
%assign %%n 1
%rep 22
ALIGN 128
.emuedge_v_extend_ %+ %%n:
    ; extend pixels above body
%if ARCH_X86_64
    test           r3 , r3                   ; if (!start_y)
    jz .emuedge_copy_body_ %+ %%n %+ _loop   ;   goto body
%else ; ARCH_X86_32
    cmp      dword r3m, 0
    je .emuedge_copy_body_ %+ %%n %+ _loop
%endif ; ARCH_X86_64/32
    READ_NUM_BYTES  top,    %%n              ; read bytes
.emuedge_extend_top_ %+ %%n %+ _loop:        ; do {
    WRITE_NUM_BYTES top,    %%n              ;   write bytes
    add            r0 , r2                   ;   dst += linesize
%if ARCH_X86_64
    dec            r3d
%else ; ARCH_X86_32
    dec      dword r3m
%endif ; ARCH_X86_64/32
    jnz .emuedge_extend_top_ %+ %%n %+ _loop ; } while (--start_y)

    ; copy body pixels
.emuedge_copy_body_ %+ %%n %+ _loop:         ; do {
    READ_NUM_BYTES  body,   %%n              ;   read bytes
    WRITE_NUM_BYTES body,   %%n              ;   write bytes
    add            r0 , r2                   ;   dst += linesize
    add            r1 , r2                   ;   src += linesize
    dec            r4d
    jnz .emuedge_copy_body_ %+ %%n %+ _loop  ; } while (--end_y)

    ; copy bottom pixels
    test           r5 , r5                   ; if (!block_h)
    jz .emuedge_v_extend_end_ %+ %%n         ;   goto end
    sub            r1 , r2                   ; src -= linesize
    READ_NUM_BYTES  bottom, %%n              ; read bytes
.emuedge_extend_bottom_ %+ %%n %+ _loop:     ; do {
    WRITE_NUM_BYTES bottom, %%n              ;   write bytes
    add            r0 , r2                   ;   dst += linesize
    dec            r5d
    jnz .emuedge_extend_bottom_ %+ %%n %+ _loop ; } while (--block_h)

.emuedge_v_extend_end_ %+ %%n:
%if ARCH_X86_64
    ret
%else ; ARCH_X86_32
    rep ret
%endif ; ARCH_X86_64/32
%assign %%n %%n+1
%endrep
%endmacro VERTICAL_EXTEND

; left/right (horizontal) fast extend functions
; these are essentially identical to the vertical extend ones above,
; just left/right separated because number of pixels to extend is
; obviously not the same on both sides.
; for reading, pixels are placed in eax (x86-64) or ebx (x86-64) in the
; lowest two bytes of the register (so val*0x0101), and are splatted
; into each byte of mm0 as well if n_pixels >= 8

%macro READ_V_PIXEL 2
    mov        vall, %2
    mov        valh, vall
%if %1 >= 8
    movd        mm0, vald
%if cpuflag(mmxext)
    pshufw      mm0, mm0, 0
%else ; mmx
    punpcklwd   mm0, mm0
    punpckldq   mm0, mm0
%endif ; sse
%endif ; %1 >= 8
%endmacro

%macro WRITE_V_PIXEL 2
%assign %%dst_off 0
%rep %1/8
    movq [%2+%%dst_off], mm0
%assign %%dst_off %%dst_off+8
%endrep
%if %1 & 4
%if %1 >= 8
    movd [%2+%%dst_off], mm0
%else ; %1 < 8
    mov  [%2+%%dst_off]  , valw
    mov  [%2+%%dst_off+2], valw
%endif ; %1 >=/< 8
%assign %%dst_off %%dst_off+4
%endif ; %1 & 4
%if %1&2
    mov  [%2+%%dst_off], valw
%endif ; %1 & 2
%endmacro

; r0=buf+block_h*linesize, r1=start_x, r2=linesize, r5=block_h, r6/r3=val
%macro LEFT_EXTEND 0
%assign %%n 2
%rep 11
ALIGN 64
.emuedge_extend_left_ %+ %%n:          ; do {
    sub         r0, r2                 ;   dst -= linesize
    READ_V_PIXEL  %%n, [r0+r1]         ;   read pixels
    WRITE_V_PIXEL %%n, r0              ;   write pixels
    dec         r5
    jnz .emuedge_extend_left_ %+ %%n   ; } while (--block_h)
%if ARCH_X86_64
    ret
%else ; ARCH_X86_32
    rep ret
%endif ; ARCH_X86_64/32
%assign %%n %%n+2
%endrep
%endmacro ; LEFT_EXTEND

; r3/r0=buf+block_h*linesize, r2=linesize, r8/r5=block_h, r0/r6=end_x, r6/r3=val
%macro RIGHT_EXTEND 0
%assign %%n 2
%rep 11
ALIGN 64
.emuedge_extend_right_ %+ %%n:          ; do {
%if ARCH_X86_64
    sub        r3, r2                   ;   dst -= linesize
    READ_V_PIXEL  %%n, [r3+w_reg-1]     ;   read pixels
    WRITE_V_PIXEL %%n, r3+r4-%%n        ;   write pixels
    dec       r8
%else ; ARCH_X86_32
    sub        r0, r2                   ;   dst -= linesize
    READ_V_PIXEL  %%n, [r0+w_reg-1]     ;   read pixels
    WRITE_V_PIXEL %%n, r0+r4-%%n        ;   write pixels
    dec     r5
%endif ; ARCH_X86_64/32
    jnz .emuedge_extend_right_ %+ %%n   ; } while (--block_h)
%if ARCH_X86_64
    ret
%else ; ARCH_X86_32
    rep ret
%endif ; ARCH_X86_64/32
%assign %%n %%n+2
%endrep

%if ARCH_X86_32
%define stack_offset 0x10
%endif
%endmacro ; RIGHT_EXTEND

; below follow the "slow" copy/extend functions, these act on a non-fixed
; width specified in a register, and run a loop to copy the full amount
; of bytes. They are optimized for copying of large amounts of pixels per
; line, so they unconditionally splat data into mm registers to copy 8
; bytes per loop iteration. It could be considered to use xmm for x86-64
; also, but I haven't optimized this as much (i.e. FIXME)
%macro V_COPY_NPX 4-5
%if %0 == 4
    test     w_reg, %4
    jz .%1_skip_%4_px
%else ; %0 == 5
.%1_%4_px_loop:
%endif
    %3          %2, [r1+cnt_reg]
    %3 [r0+cnt_reg], %2
    add    cnt_reg, %4
%if %0 == 5
    sub      w_reg, %4
    test     w_reg, %5
    jnz .%1_%4_px_loop
%endif
.%1_skip_%4_px:
%endmacro

%macro V_COPY_ROW 2
%ifidn %1, bottom
    sub         r1, linesize
%endif
.%1_copy_loop:
    xor    cnt_reg, cnt_reg
%if notcpuflag(sse)
%define linesize r2m
    V_COPY_NPX %1,  mm0, movq,    8, 0xFFFFFFF8
%else ; sse
    V_COPY_NPX %1, xmm0, movups, 16, 0xFFFFFFF0
%if ARCH_X86_64
%define linesize r2
    V_COPY_NPX %1, rax , mov,     8
%else ; ARCH_X86_32
%define linesize r2m
    V_COPY_NPX %1,  mm0, movq,    8
%endif ; ARCH_X86_64/32
%endif ; sse
    V_COPY_NPX %1, vald, mov,     4
    V_COPY_NPX %1, valw, mov,     2
    V_COPY_NPX %1, vall, mov,     1
    mov      w_reg, cnt_reg
%ifidn %1, body
    add         r1, linesize
%endif
    add         r0, linesize
    dec         %2
    jnz .%1_copy_loop
%endmacro

%macro SLOW_V_EXTEND 0
.slow_v_extend_loop:
; r0=buf,r1=src,r2(64)/r2m(32)=linesize,r3(64)/r3m(32)=start_x,r4=end_y,r5=block_h
; r8(64)/r3(later-64)/r2(32)=cnt_reg,r6(64)/r3(32)=val_reg,r7(64)/r6(32)=w=end_x-start_x
%if ARCH_X86_64
    push        r8              ; save old value of block_h
    test        r3, r3
%define cnt_reg r8
    jz .do_body_copy            ; if (!start_y) goto do_body_copy
    V_COPY_ROW top, r3
%else
    cmp  dword r3m, 0
%define cnt_reg r2
    je .do_body_copy            ; if (!start_y) goto do_body_copy
    V_COPY_ROW top, dword r3m
%endif

.do_body_copy:
    V_COPY_ROW body, r4

%if ARCH_X86_64
    pop         r8              ; restore old value of block_h
%define cnt_reg r3
%endif
    test        r5, r5
%if ARCH_X86_64
    jz .v_extend_end
%else
    jz .skip_bottom_extend
%endif
    V_COPY_ROW bottom, r5
%if ARCH_X86_32
.skip_bottom_extend:
    mov         r2, r2m
%endif
    jmp .v_extend_end
%endmacro

%macro SLOW_LEFT_EXTEND 0
.slow_left_extend_loop:
; r0=buf+block_h*linesize,r2=linesize,r6(64)/r3(32)=val,r5=block_h,r4=cntr,r7/r6=start_x
    mov         r4, 8
    sub         r0, linesize
    READ_V_PIXEL 8, [r0+w_reg]
.left_extend_8px_loop:
    movq [r0+r4-8], mm0
    add         r4, 8
    cmp         r4, w_reg
    jle .left_extend_8px_loop
    sub         r4, 8
    cmp         r4, w_reg
    jge .left_extend_loop_end
.left_extend_2px_loop:
    mov    [r0+r4], valw
    add         r4, 2
    cmp         r4, w_reg
    jl .left_extend_2px_loop
.left_extend_loop_end:
    dec         r5
    jnz .slow_left_extend_loop
%if ARCH_X86_32
    mov         r2, r2m
%endif
    jmp .right_extend
%endmacro

%macro SLOW_RIGHT_EXTEND 0
.slow_right_extend_loop:
; r3(64)/r0(32)=buf+block_h*linesize,r2=linesize,r4=block_w,r8(64)/r5(32)=block_h,
; r7(64)/r6(32)=end_x,r6/r3=val,r1=cntr
%if ARCH_X86_64
%define buf_reg r3
%define bh_reg r8
%else
%define buf_reg r0
%define bh_reg r5
%endif
    lea         r1, [r4-8]
    sub    buf_reg, linesize
    READ_V_PIXEL 8, [buf_reg+w_reg-1]
.right_extend_8px_loop:
    movq [buf_reg+r1], mm0
    sub         r1, 8
    cmp         r1, w_reg
    jge .right_extend_8px_loop
    add         r1, 8
    cmp         r1, w_reg
    je .right_extend_loop_end
.right_extend_2px_loop:
    sub         r1, 2
    mov [buf_reg+r1], valw
    cmp         r1, w_reg
    jg .right_extend_2px_loop
.right_extend_loop_end:
    dec         bh_reg
    jnz .slow_right_extend_loop
    jmp .h_extend_end
%endmacro

%macro emu_edge 1
INIT_XMM %1
EMU_EDGE_FUNC
VERTICAL_EXTEND
LEFT_EXTEND
RIGHT_EXTEND
SLOW_V_EXTEND
SLOW_LEFT_EXTEND
SLOW_RIGHT_EXTEND
%endmacro

emu_edge sse
%if ARCH_X86_32
emu_edge mmx
%endif

%macro PREFETCH_FN 1
cglobal prefetch, 3, 3, 0, buf, stride, h
.loop:
    %1      [bufq]
    add      bufq, strideq
    dec        hd
    jg .loop
    REP_RET
%endmacro

INIT_MMX mmxext
PREFETCH_FN prefetcht0
%if ARCH_X86_32
INIT_MMX 3dnow
PREFETCH_FN prefetch
%endif