summaryrefslogtreecommitdiff
path: root/media/libjpeg/simd/jidctflt-3dn.asm
blob: 99356f20a4b7d41384d467df0a73a267c87e1827 (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
;
; jidctflt.asm - floating-point IDCT (3DNow! & MMX)
;
; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
;
; Based on the 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
;
; This file contains a floating-point implementation of the inverse DCT
; (Discrete Cosine Transform). The following code is based directly on
; the IJG's original jidctflt.c; see the jidctflt.c for more details.
;
; [TAB8]

%include "jsimdext.inc"
%include "jdct.inc"

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

        alignz  16
        global  EXTN(jconst_idct_float_3dnow)

EXTN(jconst_idct_float_3dnow):

PD_1_414        times 2 dd  1.414213562373095048801689
PD_1_847        times 2 dd  1.847759065022573512256366
PD_1_082        times 2 dd  1.082392200292393968799446
PD_2_613        times 2 dd  2.613125929752753055713286
PD_RNDINT_MAGIC times 2 dd  100663296.0 ; (float)(0x00C00000 << 3)
PB_CENTERJSAMP  times 8 db  CENTERJSAMPLE

        alignz  16

; --------------------------------------------------------------------------
        SECTION SEG_TEXT
        BITS    32
;
; Perform dequantization and inverse DCT on one block of coefficients.
;
; GLOBAL(void)
; jsimd_idct_float_3dnow (void *dct_table, JCOEFPTR coef_block,
;                         JSAMPARRAY output_buf, JDIMENSION output_col)
;

%define dct_table(b)    (b)+8           ; void *dct_table
%define coef_block(b)   (b)+12          ; JCOEFPTR coef_block
%define output_buf(b)   (b)+16          ; JSAMPARRAY output_buf
%define output_col(b)   (b)+20          ; JDIMENSION output_col

%define original_ebp    ebp+0
%define wk(i)           ebp-(WK_NUM-(i))*SIZEOF_MMWORD  ; mmword wk[WK_NUM]
%define WK_NUM          2
%define workspace       wk(0)-DCTSIZE2*SIZEOF_FAST_FLOAT
                                        ; FAST_FLOAT workspace[DCTSIZE2]

        align   16
        global  EXTN(jsimd_idct_float_3dnow)

EXTN(jsimd_idct_float_3dnow):
        push    ebp
        mov     eax,esp                         ; eax = original ebp
        sub     esp, byte 4
        and     esp, byte (-SIZEOF_MMWORD)      ; align to 64 bits
        mov     [esp],eax
        mov     ebp,esp                         ; ebp = aligned ebp
        lea     esp, [workspace]
        push    ebx
;       push    ecx             ; need not be preserved
;       push    edx             ; need not be preserved
        push    esi
        push    edi

        get_GOT ebx             ; get GOT address

        ; ---- Pass 1: process columns from input, store into work array.

;       mov     eax, [original_ebp]
        mov     edx, POINTER [dct_table(eax)]           ; quantptr
        mov     esi, JCOEFPTR [coef_block(eax)]         ; inptr
        lea     edi, [workspace]                        ; FAST_FLOAT *wsptr
        mov     ecx, DCTSIZE/2                          ; ctr
        alignx  16,7
.columnloop:
%ifndef NO_ZERO_COLUMN_TEST_FLOAT_3DNOW
        mov     eax, DWORD [DWBLOCK(1,0,esi,SIZEOF_JCOEF)]
        or      eax, DWORD [DWBLOCK(2,0,esi,SIZEOF_JCOEF)]
        jnz     short .columnDCT

        pushpic ebx             ; save GOT address
        mov     ebx, DWORD [DWBLOCK(3,0,esi,SIZEOF_JCOEF)]
        mov     eax, DWORD [DWBLOCK(4,0,esi,SIZEOF_JCOEF)]
        or      ebx, DWORD [DWBLOCK(5,0,esi,SIZEOF_JCOEF)]
        or      eax, DWORD [DWBLOCK(6,0,esi,SIZEOF_JCOEF)]
        or      ebx, DWORD [DWBLOCK(7,0,esi,SIZEOF_JCOEF)]
        or      eax,ebx
        poppic  ebx             ; restore GOT address
        jnz     short .columnDCT

        ; -- AC terms all zero

        movd      mm0, DWORD [DWBLOCK(0,0,esi,SIZEOF_JCOEF)]

        punpcklwd mm0,mm0
        psrad     mm0,(DWORD_BIT-WORD_BIT)
        pi2fd     mm0,mm0

        pfmul     mm0, MMWORD [MMBLOCK(0,0,edx,SIZEOF_FLOAT_MULT_TYPE)]

        movq      mm1,mm0
        punpckldq mm0,mm0
        punpckhdq mm1,mm1

        movq    MMWORD [MMBLOCK(0,0,edi,SIZEOF_FAST_FLOAT)], mm0
        movq    MMWORD [MMBLOCK(0,1,edi,SIZEOF_FAST_FLOAT)], mm0
        movq    MMWORD [MMBLOCK(0,2,edi,SIZEOF_FAST_FLOAT)], mm0
        movq    MMWORD [MMBLOCK(0,3,edi,SIZEOF_FAST_FLOAT)], mm0
        movq    MMWORD [MMBLOCK(1,0,edi,SIZEOF_FAST_FLOAT)], mm1
        movq    MMWORD [MMBLOCK(1,1,edi,SIZEOF_FAST_FLOAT)], mm1
        movq    MMWORD [MMBLOCK(1,2,edi,SIZEOF_FAST_FLOAT)], mm1
        movq    MMWORD [MMBLOCK(1,3,edi,SIZEOF_FAST_FLOAT)], mm1
        jmp     near .nextcolumn
        alignx  16,7
%endif
.columnDCT:

        ; -- Even part

        movd      mm0, DWORD [DWBLOCK(0,0,esi,SIZEOF_JCOEF)]
        movd      mm1, DWORD [DWBLOCK(2,0,esi,SIZEOF_JCOEF)]
        movd      mm2, DWORD [DWBLOCK(4,0,esi,SIZEOF_JCOEF)]
        movd      mm3, DWORD [DWBLOCK(6,0,esi,SIZEOF_JCOEF)]

        punpcklwd mm0,mm0
        punpcklwd mm1,mm1
        psrad     mm0,(DWORD_BIT-WORD_BIT)
        psrad     mm1,(DWORD_BIT-WORD_BIT)
        pi2fd     mm0,mm0
        pi2fd     mm1,mm1

        pfmul     mm0, MMWORD [MMBLOCK(0,0,edx,SIZEOF_FLOAT_MULT_TYPE)]
        pfmul     mm1, MMWORD [MMBLOCK(2,0,edx,SIZEOF_FLOAT_MULT_TYPE)]

        punpcklwd mm2,mm2
        punpcklwd mm3,mm3
        psrad     mm2,(DWORD_BIT-WORD_BIT)
        psrad     mm3,(DWORD_BIT-WORD_BIT)
        pi2fd     mm2,mm2
        pi2fd     mm3,mm3

        pfmul     mm2, MMWORD [MMBLOCK(4,0,edx,SIZEOF_FLOAT_MULT_TYPE)]
        pfmul     mm3, MMWORD [MMBLOCK(6,0,edx,SIZEOF_FLOAT_MULT_TYPE)]

        movq    mm4,mm0
        movq    mm5,mm1
        pfsub   mm0,mm2                 ; mm0=tmp11
        pfsub   mm1,mm3
        pfadd   mm4,mm2                 ; mm4=tmp10
        pfadd   mm5,mm3                 ; mm5=tmp13

        pfmul   mm1,[GOTOFF(ebx,PD_1_414)]
        pfsub   mm1,mm5                 ; mm1=tmp12

        movq    mm6,mm4
        movq    mm7,mm0
        pfsub   mm4,mm5                 ; mm4=tmp3
        pfsub   mm0,mm1                 ; mm0=tmp2
        pfadd   mm6,mm5                 ; mm6=tmp0
        pfadd   mm7,mm1                 ; mm7=tmp1

        movq    MMWORD [wk(1)], mm4     ; tmp3
        movq    MMWORD [wk(0)], mm0     ; tmp2

        ; -- Odd part

        movd      mm2, DWORD [DWBLOCK(1,0,esi,SIZEOF_JCOEF)]
        movd      mm3, DWORD [DWBLOCK(3,0,esi,SIZEOF_JCOEF)]
        movd      mm5, DWORD [DWBLOCK(5,0,esi,SIZEOF_JCOEF)]
        movd      mm1, DWORD [DWBLOCK(7,0,esi,SIZEOF_JCOEF)]

        punpcklwd mm2,mm2
        punpcklwd mm3,mm3
        psrad     mm2,(DWORD_BIT-WORD_BIT)
        psrad     mm3,(DWORD_BIT-WORD_BIT)
        pi2fd     mm2,mm2
        pi2fd     mm3,mm3

        pfmul     mm2, MMWORD [MMBLOCK(1,0,edx,SIZEOF_FLOAT_MULT_TYPE)]
        pfmul     mm3, MMWORD [MMBLOCK(3,0,edx,SIZEOF_FLOAT_MULT_TYPE)]

        punpcklwd mm5,mm5
        punpcklwd mm1,mm1
        psrad     mm5,(DWORD_BIT-WORD_BIT)
        psrad     mm1,(DWORD_BIT-WORD_BIT)
        pi2fd     mm5,mm5
        pi2fd     mm1,mm1

        pfmul     mm5, MMWORD [MMBLOCK(5,0,edx,SIZEOF_FLOAT_MULT_TYPE)]
        pfmul     mm1, MMWORD [MMBLOCK(7,0,edx,SIZEOF_FLOAT_MULT_TYPE)]

        movq    mm4,mm2
        movq    mm0,mm5
        pfadd   mm2,mm1                 ; mm2=z11
        pfadd   mm5,mm3                 ; mm5=z13
        pfsub   mm4,mm1                 ; mm4=z12
        pfsub   mm0,mm3                 ; mm0=z10

        movq    mm1,mm2
        pfsub   mm2,mm5
        pfadd   mm1,mm5                 ; mm1=tmp7

        pfmul   mm2,[GOTOFF(ebx,PD_1_414)]      ; mm2=tmp11

        movq    mm3,mm0
        pfadd   mm0,mm4
        pfmul   mm0,[GOTOFF(ebx,PD_1_847)]      ; mm0=z5
        pfmul   mm3,[GOTOFF(ebx,PD_2_613)]      ; mm3=(z10 * 2.613125930)
        pfmul   mm4,[GOTOFF(ebx,PD_1_082)]      ; mm4=(z12 * 1.082392200)
        pfsubr  mm3,mm0                 ; mm3=tmp12
        pfsub   mm4,mm0                 ; mm4=tmp10

        ; -- Final output stage

        pfsub   mm3,mm1                 ; mm3=tmp6
        movq    mm5,mm6
        movq    mm0,mm7
        pfadd   mm6,mm1                 ; mm6=data0=(00 01)
        pfadd   mm7,mm3                 ; mm7=data1=(10 11)
        pfsub   mm5,mm1                 ; mm5=data7=(70 71)
        pfsub   mm0,mm3                 ; mm0=data6=(60 61)
        pfsub   mm2,mm3                 ; mm2=tmp5

        movq      mm1,mm6               ; transpose coefficients
        punpckldq mm6,mm7               ; mm6=(00 10)
        punpckhdq mm1,mm7               ; mm1=(01 11)
        movq      mm3,mm0               ; transpose coefficients
        punpckldq mm0,mm5               ; mm0=(60 70)
        punpckhdq mm3,mm5               ; mm3=(61 71)

        movq    MMWORD [MMBLOCK(0,0,edi,SIZEOF_FAST_FLOAT)], mm6
        movq    MMWORD [MMBLOCK(1,0,edi,SIZEOF_FAST_FLOAT)], mm1
        movq    MMWORD [MMBLOCK(0,3,edi,SIZEOF_FAST_FLOAT)], mm0
        movq    MMWORD [MMBLOCK(1,3,edi,SIZEOF_FAST_FLOAT)], mm3

        movq    mm7, MMWORD [wk(0)]     ; mm7=tmp2
        movq    mm5, MMWORD [wk(1)]     ; mm5=tmp3

        pfadd   mm4,mm2                 ; mm4=tmp4
        movq    mm6,mm7
        movq    mm1,mm5
        pfadd   mm7,mm2                 ; mm7=data2=(20 21)
        pfadd   mm5,mm4                 ; mm5=data4=(40 41)
        pfsub   mm6,mm2                 ; mm6=data5=(50 51)
        pfsub   mm1,mm4                 ; mm1=data3=(30 31)

        movq      mm0,mm7               ; transpose coefficients
        punpckldq mm7,mm1               ; mm7=(20 30)
        punpckhdq mm0,mm1               ; mm0=(21 31)
        movq      mm3,mm5               ; transpose coefficients
        punpckldq mm5,mm6               ; mm5=(40 50)
        punpckhdq mm3,mm6               ; mm3=(41 51)

        movq    MMWORD [MMBLOCK(0,1,edi,SIZEOF_FAST_FLOAT)], mm7
        movq    MMWORD [MMBLOCK(1,1,edi,SIZEOF_FAST_FLOAT)], mm0
        movq    MMWORD [MMBLOCK(0,2,edi,SIZEOF_FAST_FLOAT)], mm5
        movq    MMWORD [MMBLOCK(1,2,edi,SIZEOF_FAST_FLOAT)], mm3

.nextcolumn:
        add     esi, byte 2*SIZEOF_JCOEF                ; coef_block
        add     edx, byte 2*SIZEOF_FLOAT_MULT_TYPE      ; quantptr
        add     edi, byte 2*DCTSIZE*SIZEOF_FAST_FLOAT   ; wsptr
        dec     ecx                                     ; ctr
        jnz     near .columnloop

        ; -- Prefetch the next coefficient block

        prefetch [esi + (DCTSIZE2-8)*SIZEOF_JCOEF + 0*32]
        prefetch [esi + (DCTSIZE2-8)*SIZEOF_JCOEF + 1*32]
        prefetch [esi + (DCTSIZE2-8)*SIZEOF_JCOEF + 2*32]
        prefetch [esi + (DCTSIZE2-8)*SIZEOF_JCOEF + 3*32]

        ; ---- Pass 2: process rows from work array, store into output array.

        mov     eax, [original_ebp]
        lea     esi, [workspace]                        ; FAST_FLOAT *wsptr
        mov     edi, JSAMPARRAY [output_buf(eax)]       ; (JSAMPROW *)
        mov     eax, JDIMENSION [output_col(eax)]
        mov     ecx, DCTSIZE/2                          ; ctr
        alignx  16,7
.rowloop:

        ; -- Even part

        movq    mm0, MMWORD [MMBLOCK(0,0,esi,SIZEOF_FAST_FLOAT)]
        movq    mm1, MMWORD [MMBLOCK(2,0,esi,SIZEOF_FAST_FLOAT)]
        movq    mm2, MMWORD [MMBLOCK(4,0,esi,SIZEOF_FAST_FLOAT)]
        movq    mm3, MMWORD [MMBLOCK(6,0,esi,SIZEOF_FAST_FLOAT)]

        movq    mm4,mm0
        movq    mm5,mm1
        pfsub   mm0,mm2                 ; mm0=tmp11
        pfsub   mm1,mm3
        pfadd   mm4,mm2                 ; mm4=tmp10
        pfadd   mm5,mm3                 ; mm5=tmp13

        pfmul   mm1,[GOTOFF(ebx,PD_1_414)]
        pfsub   mm1,mm5                 ; mm1=tmp12

        movq    mm6,mm4
        movq    mm7,mm0
        pfsub   mm4,mm5                 ; mm4=tmp3
        pfsub   mm0,mm1                 ; mm0=tmp2
        pfadd   mm6,mm5                 ; mm6=tmp0
        pfadd   mm7,mm1                 ; mm7=tmp1

        movq    MMWORD [wk(1)], mm4     ; tmp3
        movq    MMWORD [wk(0)], mm0     ; tmp2

        ; -- Odd part

        movq    mm2, MMWORD [MMBLOCK(1,0,esi,SIZEOF_FAST_FLOAT)]
        movq    mm3, MMWORD [MMBLOCK(3,0,esi,SIZEOF_FAST_FLOAT)]
        movq    mm5, MMWORD [MMBLOCK(5,0,esi,SIZEOF_FAST_FLOAT)]
        movq    mm1, MMWORD [MMBLOCK(7,0,esi,SIZEOF_FAST_FLOAT)]

        movq    mm4,mm2
        movq    mm0,mm5
        pfadd   mm2,mm1                 ; mm2=z11
        pfadd   mm5,mm3                 ; mm5=z13
        pfsub   mm4,mm1                 ; mm4=z12
        pfsub   mm0,mm3                 ; mm0=z10

        movq    mm1,mm2
        pfsub   mm2,mm5
        pfadd   mm1,mm5                 ; mm1=tmp7

        pfmul   mm2,[GOTOFF(ebx,PD_1_414)]      ; mm2=tmp11

        movq    mm3,mm0
        pfadd   mm0,mm4
        pfmul   mm0,[GOTOFF(ebx,PD_1_847)]      ; mm0=z5
        pfmul   mm3,[GOTOFF(ebx,PD_2_613)]      ; mm3=(z10 * 2.613125930)
        pfmul   mm4,[GOTOFF(ebx,PD_1_082)]      ; mm4=(z12 * 1.082392200)
        pfsubr  mm3,mm0                 ; mm3=tmp12
        pfsub   mm4,mm0                 ; mm4=tmp10

        ; -- Final output stage

        pfsub   mm3,mm1                 ; mm3=tmp6
        movq    mm5,mm6
        movq    mm0,mm7
        pfadd   mm6,mm1                 ; mm6=data0=(00 10)
        pfadd   mm7,mm3                 ; mm7=data1=(01 11)
        pfsub   mm5,mm1                 ; mm5=data7=(07 17)
        pfsub   mm0,mm3                 ; mm0=data6=(06 16)
        pfsub   mm2,mm3                 ; mm2=tmp5

        movq    mm1,[GOTOFF(ebx,PD_RNDINT_MAGIC)]       ; mm1=[PD_RNDINT_MAGIC]
        pcmpeqd mm3,mm3
        psrld   mm3,WORD_BIT            ; mm3={0xFFFF 0x0000 0xFFFF 0x0000}

        pfadd   mm6,mm1                 ; mm6=roundint(data0/8)=(00 ** 10 **)
        pfadd   mm7,mm1                 ; mm7=roundint(data1/8)=(01 ** 11 **)
        pfadd   mm0,mm1                 ; mm0=roundint(data6/8)=(06 ** 16 **)
        pfadd   mm5,mm1                 ; mm5=roundint(data7/8)=(07 ** 17 **)

        pand    mm6,mm3                 ; mm6=(00 -- 10 --)
        pslld   mm7,WORD_BIT            ; mm7=(-- 01 -- 11)
        pand    mm0,mm3                 ; mm0=(06 -- 16 --)
        pslld   mm5,WORD_BIT            ; mm5=(-- 07 -- 17)
        por     mm6,mm7                 ; mm6=(00 01 10 11)
        por     mm0,mm5                 ; mm0=(06 07 16 17)

        movq    mm1, MMWORD [wk(0)]     ; mm1=tmp2
        movq    mm3, MMWORD [wk(1)]     ; mm3=tmp3

        pfadd   mm4,mm2                 ; mm4=tmp4
        movq    mm7,mm1
        movq    mm5,mm3
        pfadd   mm1,mm2                 ; mm1=data2=(02 12)
        pfadd   mm3,mm4                 ; mm3=data4=(04 14)
        pfsub   mm7,mm2                 ; mm7=data5=(05 15)
        pfsub   mm5,mm4                 ; mm5=data3=(03 13)

        movq    mm2,[GOTOFF(ebx,PD_RNDINT_MAGIC)]       ; mm2=[PD_RNDINT_MAGIC]
        pcmpeqd mm4,mm4
        psrld   mm4,WORD_BIT            ; mm4={0xFFFF 0x0000 0xFFFF 0x0000}

        pfadd   mm3,mm2                 ; mm3=roundint(data4/8)=(04 ** 14 **)
        pfadd   mm7,mm2                 ; mm7=roundint(data5/8)=(05 ** 15 **)
        pfadd   mm1,mm2                 ; mm1=roundint(data2/8)=(02 ** 12 **)
        pfadd   mm5,mm2                 ; mm5=roundint(data3/8)=(03 ** 13 **)

        pand    mm3,mm4                 ; mm3=(04 -- 14 --)
        pslld   mm7,WORD_BIT            ; mm7=(-- 05 -- 15)
        pand    mm1,mm4                 ; mm1=(02 -- 12 --)
        pslld   mm5,WORD_BIT            ; mm5=(-- 03 -- 13)
        por     mm3,mm7                 ; mm3=(04 05 14 15)
        por     mm1,mm5                 ; mm1=(02 03 12 13)

        movq      mm2,[GOTOFF(ebx,PB_CENTERJSAMP)]      ; mm2=[PB_CENTERJSAMP]

        packsswb  mm6,mm3               ; mm6=(00 01 10 11 04 05 14 15)
        packsswb  mm1,mm0               ; mm1=(02 03 12 13 06 07 16 17)
        paddb     mm6,mm2
        paddb     mm1,mm2

        movq      mm4,mm6               ; transpose coefficients(phase 2)
        punpcklwd mm6,mm1               ; mm6=(00 01 02 03 10 11 12 13)
        punpckhwd mm4,mm1               ; mm4=(04 05 06 07 14 15 16 17)

        movq      mm7,mm6               ; transpose coefficients(phase 3)
        punpckldq mm6,mm4               ; mm6=(00 01 02 03 04 05 06 07)
        punpckhdq mm7,mm4               ; mm7=(10 11 12 13 14 15 16 17)

        pushpic ebx                     ; save GOT address

        mov     edx, JSAMPROW [edi+0*SIZEOF_JSAMPROW]
        mov     ebx, JSAMPROW [edi+1*SIZEOF_JSAMPROW]
        movq    MMWORD [edx+eax*SIZEOF_JSAMPLE], mm6
        movq    MMWORD [ebx+eax*SIZEOF_JSAMPLE], mm7

        poppic  ebx                     ; restore GOT address

        add     esi, byte 2*SIZEOF_FAST_FLOAT   ; wsptr
        add     edi, byte 2*SIZEOF_JSAMPROW
        dec     ecx                             ; ctr
        jnz     near .rowloop

        femms           ; empty MMX/3DNow! state

        pop     edi
        pop     esi
;       pop     edx             ; need not be preserved
;       pop     ecx             ; need not be preserved
        pop     ebx
        mov     esp,ebp         ; esp <- aligned ebp
        pop     esp             ; esp <- original ebp
        pop     ebp
        ret

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