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1;
2; jidctfst.asm - fast integer IDCT (MMX)
3;
4; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
5; Copyright (C) 2016, D. R. Commander.
6;
7; Based on the x86 SIMD extension for IJG JPEG library
8; Copyright (C) 1999-2006, MIYASAKA Masaru.
9; For conditions of distribution and use, see copyright notice in jsimdext.inc
10;
11; This file should be assembled with NASM (Netwide Assembler),
12; can *not* be assembled with Microsoft's MASM or any compatible
13; assembler (including Borland's Turbo Assembler).
14; NASM is available from http://nasm.sourceforge.net/ or
15; http://sourceforge.net/project/showfiles.php?group_id=6208
16;
17; This file contains a fast, not so accurate integer implementation of
18; the inverse DCT (Discrete Cosine Transform). The following code is
19; based directly on the IJG's original jidctfst.c; see the jidctfst.c
20; for more details.
21;
22; [TAB8]
23
24%include "jsimdext.inc"
25%include "jdct.inc"
26
27; --------------------------------------------------------------------------
28
29%define CONST_BITS  8  ; 14 is also OK.
30%define PASS1_BITS  2
31
32%if IFAST_SCALE_BITS != PASS1_BITS
33%error "'IFAST_SCALE_BITS' must be equal to 'PASS1_BITS'."
34%endif
35
36%if CONST_BITS == 8
37F_1_082 equ 277              ; FIX(1.082392200)
38F_1_414 equ 362              ; FIX(1.414213562)
39F_1_847 equ 473              ; FIX(1.847759065)
40F_2_613 equ 669              ; FIX(2.613125930)
41F_1_613 equ (F_2_613 - 256)  ; FIX(2.613125930) - FIX(1)
42%else
43; NASM cannot do compile-time arithmetic on floating-point constants.
44%define DESCALE(x, n)  (((x) + (1 << ((n) - 1))) >> (n))
45F_1_082 equ DESCALE(1162209775, 30 - CONST_BITS)  ; FIX(1.082392200)
46F_1_414 equ DESCALE(1518500249, 30 - CONST_BITS)  ; FIX(1.414213562)
47F_1_847 equ DESCALE(1984016188, 30 - CONST_BITS)  ; FIX(1.847759065)
48F_2_613 equ DESCALE(2805822602, 30 - CONST_BITS)  ; FIX(2.613125930)
49F_1_613 equ (F_2_613 - (1 << CONST_BITS))       ; FIX(2.613125930) - FIX(1)
50%endif
51
52; --------------------------------------------------------------------------
53    SECTION     SEG_CONST
54
55; PRE_MULTIPLY_SCALE_BITS <= 2 (to avoid overflow)
56; CONST_BITS + CONST_SHIFT + PRE_MULTIPLY_SCALE_BITS == 16 (for pmulhw)
57
58%define PRE_MULTIPLY_SCALE_BITS  2
59%define CONST_SHIFT              (16 - PRE_MULTIPLY_SCALE_BITS - CONST_BITS)
60
61    alignz      32
62    GLOBAL_DATA(jconst_idct_ifast_mmx)
63
64EXTN(jconst_idct_ifast_mmx):
65
66PW_F1414       times 4 dw  F_1_414 << CONST_SHIFT
67PW_F1847       times 4 dw  F_1_847 << CONST_SHIFT
68PW_MF1613      times 4 dw -F_1_613 << CONST_SHIFT
69PW_F1082       times 4 dw  F_1_082 << CONST_SHIFT
70PB_CENTERJSAMP times 8 db  CENTERJSAMPLE
71
72    alignz      32
73
74; --------------------------------------------------------------------------
75    SECTION     SEG_TEXT
76    BITS        32
77;
78; Perform dequantization and inverse DCT on one block of coefficients.
79;
80; GLOBAL(void)
81; jsimd_idct_ifast_mmx(void *dct_table, JCOEFPTR coef_block,
82;                      JSAMPARRAY output_buf, JDIMENSION output_col)
83;
84
85%define dct_table(b)   (b) + 8          ; jpeg_component_info *compptr
86%define coef_block(b)  (b) + 12         ; JCOEFPTR coef_block
87%define output_buf(b)  (b) + 16         ; JSAMPARRAY output_buf
88%define output_col(b)  (b) + 20         ; JDIMENSION output_col
89
90%define original_ebp   ebp + 0
91%define wk(i)          ebp - (WK_NUM - (i)) * SIZEOF_MMWORD
92                                        ; mmword wk[WK_NUM]
93%define WK_NUM         2
94%define workspace      wk(0) - DCTSIZE2 * SIZEOF_JCOEF
95                                        ; JCOEF workspace[DCTSIZE2]
96
97    align       32
98    GLOBAL_FUNCTION(jsimd_idct_ifast_mmx)
99
100EXTN(jsimd_idct_ifast_mmx):
101    push        ebp
102    mov         eax, esp                    ; eax = original ebp
103    sub         esp, byte 4
104    and         esp, byte (-SIZEOF_MMWORD)  ; align to 64 bits
105    mov         [esp], eax
106    mov         ebp, esp                    ; ebp = aligned ebp
107    lea         esp, [workspace]
108    push        ebx
109;   push        ecx                     ; need not be preserved
110;   push        edx                     ; need not be preserved
111    push        esi
112    push        edi
113
114    get_GOT     ebx                     ; get GOT address
115
116    ; ---- Pass 1: process columns from input, store into work array.
117
118;   mov         eax, [original_ebp]
119    mov         edx, POINTER [dct_table(eax)]    ; quantptr
120    mov         esi, JCOEFPTR [coef_block(eax)]  ; inptr
121    lea         edi, [workspace]                 ; JCOEF *wsptr
122    mov         ecx, DCTSIZE/4                   ; ctr
123    alignx      16, 7
124.columnloop:
125%ifndef NO_ZERO_COLUMN_TEST_IFAST_MMX
126    mov         eax, DWORD [DWBLOCK(1,0,esi,SIZEOF_JCOEF)]
127    or          eax, DWORD [DWBLOCK(2,0,esi,SIZEOF_JCOEF)]
128    jnz         short .columnDCT
129
130    movq        mm0, MMWORD [MMBLOCK(1,0,esi,SIZEOF_JCOEF)]
131    movq        mm1, MMWORD [MMBLOCK(2,0,esi,SIZEOF_JCOEF)]
132    por         mm0, MMWORD [MMBLOCK(3,0,esi,SIZEOF_JCOEF)]
133    por         mm1, MMWORD [MMBLOCK(4,0,esi,SIZEOF_JCOEF)]
134    por         mm0, MMWORD [MMBLOCK(5,0,esi,SIZEOF_JCOEF)]
135    por         mm1, MMWORD [MMBLOCK(6,0,esi,SIZEOF_JCOEF)]
136    por         mm0, MMWORD [MMBLOCK(7,0,esi,SIZEOF_JCOEF)]
137    por         mm1, mm0
138    packsswb    mm1, mm1
139    movd        eax, mm1
140    test        eax, eax
141    jnz         short .columnDCT
142
143    ; -- AC terms all zero
144
145    movq        mm0, MMWORD [MMBLOCK(0,0,esi,SIZEOF_JCOEF)]
146    pmullw      mm0, MMWORD [MMBLOCK(0,0,edx,SIZEOF_IFAST_MULT_TYPE)]
147
148    movq        mm2, mm0                ; mm0=in0=(00 01 02 03)
149    punpcklwd   mm0, mm0                ; mm0=(00 00 01 01)
150    punpckhwd   mm2, mm2                ; mm2=(02 02 03 03)
151
152    movq        mm1, mm0
153    punpckldq   mm0, mm0                ; mm0=(00 00 00 00)
154    punpckhdq   mm1, mm1                ; mm1=(01 01 01 01)
155    movq        mm3, mm2
156    punpckldq   mm2, mm2                ; mm2=(02 02 02 02)
157    punpckhdq   mm3, mm3                ; mm3=(03 03 03 03)
158
159    movq        MMWORD [MMBLOCK(0,0,edi,SIZEOF_JCOEF)], mm0
160    movq        MMWORD [MMBLOCK(0,1,edi,SIZEOF_JCOEF)], mm0
161    movq        MMWORD [MMBLOCK(1,0,edi,SIZEOF_JCOEF)], mm1
162    movq        MMWORD [MMBLOCK(1,1,edi,SIZEOF_JCOEF)], mm1
163    movq        MMWORD [MMBLOCK(2,0,edi,SIZEOF_JCOEF)], mm2
164    movq        MMWORD [MMBLOCK(2,1,edi,SIZEOF_JCOEF)], mm2
165    movq        MMWORD [MMBLOCK(3,0,edi,SIZEOF_JCOEF)], mm3
166    movq        MMWORD [MMBLOCK(3,1,edi,SIZEOF_JCOEF)], mm3
167    jmp         near .nextcolumn
168    alignx      16, 7
169%endif
170.columnDCT:
171
172    ; -- Even part
173
174    movq        mm0, MMWORD [MMBLOCK(0,0,esi,SIZEOF_JCOEF)]
175    movq        mm1, MMWORD [MMBLOCK(2,0,esi,SIZEOF_JCOEF)]
176    pmullw      mm0, MMWORD [MMBLOCK(0,0,edx,SIZEOF_IFAST_MULT_TYPE)]
177    pmullw      mm1, MMWORD [MMBLOCK(2,0,edx,SIZEOF_IFAST_MULT_TYPE)]
178    movq        mm2, MMWORD [MMBLOCK(4,0,esi,SIZEOF_JCOEF)]
179    movq        mm3, MMWORD [MMBLOCK(6,0,esi,SIZEOF_JCOEF)]
180    pmullw      mm2, MMWORD [MMBLOCK(4,0,edx,SIZEOF_IFAST_MULT_TYPE)]
181    pmullw      mm3, MMWORD [MMBLOCK(6,0,edx,SIZEOF_IFAST_MULT_TYPE)]
182
183    movq        mm4, mm0
184    movq        mm5, mm1
185    psubw       mm0, mm2                ; mm0=tmp11
186    psubw       mm1, mm3
187    paddw       mm4, mm2                ; mm4=tmp10
188    paddw       mm5, mm3                ; mm5=tmp13
189
190    psllw       mm1, PRE_MULTIPLY_SCALE_BITS
191    pmulhw      mm1, [GOTOFF(ebx,PW_F1414)]
192    psubw       mm1, mm5                ; mm1=tmp12
193
194    movq        mm6, mm4
195    movq        mm7, mm0
196    psubw       mm4, mm5                ; mm4=tmp3
197    psubw       mm0, mm1                ; mm0=tmp2
198    paddw       mm6, mm5                ; mm6=tmp0
199    paddw       mm7, mm1                ; mm7=tmp1
200
201    movq        MMWORD [wk(1)], mm4     ; wk(1)=tmp3
202    movq        MMWORD [wk(0)], mm0     ; wk(0)=tmp2
203
204    ; -- Odd part
205
206    movq        mm2, MMWORD [MMBLOCK(1,0,esi,SIZEOF_JCOEF)]
207    movq        mm3, MMWORD [MMBLOCK(3,0,esi,SIZEOF_JCOEF)]
208    pmullw      mm2, MMWORD [MMBLOCK(1,0,edx,SIZEOF_IFAST_MULT_TYPE)]
209    pmullw      mm3, MMWORD [MMBLOCK(3,0,edx,SIZEOF_IFAST_MULT_TYPE)]
210    movq        mm5, MMWORD [MMBLOCK(5,0,esi,SIZEOF_JCOEF)]
211    movq        mm1, MMWORD [MMBLOCK(7,0,esi,SIZEOF_JCOEF)]
212    pmullw      mm5, MMWORD [MMBLOCK(5,0,edx,SIZEOF_IFAST_MULT_TYPE)]
213    pmullw      mm1, MMWORD [MMBLOCK(7,0,edx,SIZEOF_IFAST_MULT_TYPE)]
214
215    movq        mm4, mm2
216    movq        mm0, mm5
217    psubw       mm2, mm1                ; mm2=z12
218    psubw       mm5, mm3                ; mm5=z10
219    paddw       mm4, mm1                ; mm4=z11
220    paddw       mm0, mm3                ; mm0=z13
221
222    movq        mm1, mm5                ; mm1=z10(unscaled)
223    psllw       mm2, PRE_MULTIPLY_SCALE_BITS
224    psllw       mm5, PRE_MULTIPLY_SCALE_BITS
225
226    movq        mm3, mm4
227    psubw       mm4, mm0
228    paddw       mm3, mm0                ; mm3=tmp7
229
230    psllw       mm4, PRE_MULTIPLY_SCALE_BITS
231    pmulhw      mm4, [GOTOFF(ebx,PW_F1414)]  ; mm4=tmp11
232
233    ; To avoid overflow...
234    ;
235    ; (Original)
236    ; tmp12 = -2.613125930 * z10 + z5;
237    ;
238    ; (This implementation)
239    ; tmp12 = (-1.613125930 - 1) * z10 + z5;
240    ;       = -1.613125930 * z10 - z10 + z5;
241
242    movq        mm0, mm5
243    paddw       mm5, mm2
244    pmulhw      mm5, [GOTOFF(ebx,PW_F1847)]   ; mm5=z5
245    pmulhw      mm0, [GOTOFF(ebx,PW_MF1613)]
246    pmulhw      mm2, [GOTOFF(ebx,PW_F1082)]
247    psubw       mm0, mm1
248    psubw       mm2, mm5                ; mm2=tmp10
249    paddw       mm0, mm5                ; mm0=tmp12
250
251    ; -- Final output stage
252
253    psubw       mm0, mm3                ; mm0=tmp6
254    movq        mm1, mm6
255    movq        mm5, mm7
256    paddw       mm6, mm3                ; mm6=data0=(00 01 02 03)
257    paddw       mm7, mm0                ; mm7=data1=(10 11 12 13)
258    psubw       mm1, mm3                ; mm1=data7=(70 71 72 73)
259    psubw       mm5, mm0                ; mm5=data6=(60 61 62 63)
260    psubw       mm4, mm0                ; mm4=tmp5
261
262    movq        mm3, mm6                ; transpose coefficients(phase 1)
263    punpcklwd   mm6, mm7                ; mm6=(00 10 01 11)
264    punpckhwd   mm3, mm7                ; mm3=(02 12 03 13)
265    movq        mm0, mm5                ; transpose coefficients(phase 1)
266    punpcklwd   mm5, mm1                ; mm5=(60 70 61 71)
267    punpckhwd   mm0, mm1                ; mm0=(62 72 63 73)
268
269    movq        mm7, MMWORD [wk(0)]     ; mm7=tmp2
270    movq        mm1, MMWORD [wk(1)]     ; mm1=tmp3
271
272    movq        MMWORD [wk(0)], mm5     ; wk(0)=(60 70 61 71)
273    movq        MMWORD [wk(1)], mm0     ; wk(1)=(62 72 63 73)
274
275    paddw       mm2, mm4                ; mm2=tmp4
276    movq        mm5, mm7
277    movq        mm0, mm1
278    paddw       mm7, mm4                ; mm7=data2=(20 21 22 23)
279    paddw       mm1, mm2                ; mm1=data4=(40 41 42 43)
280    psubw       mm5, mm4                ; mm5=data5=(50 51 52 53)
281    psubw       mm0, mm2                ; mm0=data3=(30 31 32 33)
282
283    movq        mm4, mm7                ; transpose coefficients(phase 1)
284    punpcklwd   mm7, mm0                ; mm7=(20 30 21 31)
285    punpckhwd   mm4, mm0                ; mm4=(22 32 23 33)
286    movq        mm2, mm1                ; transpose coefficients(phase 1)
287    punpcklwd   mm1, mm5                ; mm1=(40 50 41 51)
288    punpckhwd   mm2, mm5                ; mm2=(42 52 43 53)
289
290    movq        mm0, mm6                ; transpose coefficients(phase 2)
291    punpckldq   mm6, mm7                ; mm6=(00 10 20 30)
292    punpckhdq   mm0, mm7                ; mm0=(01 11 21 31)
293    movq        mm5, mm3                ; transpose coefficients(phase 2)
294    punpckldq   mm3, mm4                ; mm3=(02 12 22 32)
295    punpckhdq   mm5, mm4                ; mm5=(03 13 23 33)
296
297    movq        mm7, MMWORD [wk(0)]     ; mm7=(60 70 61 71)
298    movq        mm4, MMWORD [wk(1)]     ; mm4=(62 72 63 73)
299
300    movq        MMWORD [MMBLOCK(0,0,edi,SIZEOF_JCOEF)], mm6
301    movq        MMWORD [MMBLOCK(1,0,edi,SIZEOF_JCOEF)], mm0
302    movq        MMWORD [MMBLOCK(2,0,edi,SIZEOF_JCOEF)], mm3
303    movq        MMWORD [MMBLOCK(3,0,edi,SIZEOF_JCOEF)], mm5
304
305    movq        mm6, mm1                ; transpose coefficients(phase 2)
306    punpckldq   mm1, mm7                ; mm1=(40 50 60 70)
307    punpckhdq   mm6, mm7                ; mm6=(41 51 61 71)
308    movq        mm0, mm2                ; transpose coefficients(phase 2)
309    punpckldq   mm2, mm4                ; mm2=(42 52 62 72)
310    punpckhdq   mm0, mm4                ; mm0=(43 53 63 73)
311
312    movq        MMWORD [MMBLOCK(0,1,edi,SIZEOF_JCOEF)], mm1
313    movq        MMWORD [MMBLOCK(1,1,edi,SIZEOF_JCOEF)], mm6
314    movq        MMWORD [MMBLOCK(2,1,edi,SIZEOF_JCOEF)], mm2
315    movq        MMWORD [MMBLOCK(3,1,edi,SIZEOF_JCOEF)], mm0
316
317.nextcolumn:
318    add         esi, byte 4*SIZEOF_JCOEF            ; coef_block
319    add         edx, byte 4*SIZEOF_IFAST_MULT_TYPE  ; quantptr
320    add         edi, byte 4*DCTSIZE*SIZEOF_JCOEF    ; wsptr
321    dec         ecx                                 ; ctr
322    jnz         near .columnloop
323
324    ; ---- Pass 2: process rows from work array, store into output array.
325
326    mov         eax, [original_ebp]
327    lea         esi, [workspace]                   ; JCOEF *wsptr
328    mov         edi, JSAMPARRAY [output_buf(eax)]  ; (JSAMPROW *)
329    mov         eax, JDIMENSION [output_col(eax)]
330    mov         ecx, DCTSIZE/4                     ; ctr
331    alignx      16, 7
332.rowloop:
333
334    ; -- Even part
335
336    movq        mm0, MMWORD [MMBLOCK(0,0,esi,SIZEOF_JCOEF)]
337    movq        mm1, MMWORD [MMBLOCK(2,0,esi,SIZEOF_JCOEF)]
338    movq        mm2, MMWORD [MMBLOCK(4,0,esi,SIZEOF_JCOEF)]
339    movq        mm3, MMWORD [MMBLOCK(6,0,esi,SIZEOF_JCOEF)]
340
341    movq        mm4, mm0
342    movq        mm5, mm1
343    psubw       mm0, mm2                ; mm0=tmp11
344    psubw       mm1, mm3
345    paddw       mm4, mm2                ; mm4=tmp10
346    paddw       mm5, mm3                ; mm5=tmp13
347
348    psllw       mm1, PRE_MULTIPLY_SCALE_BITS
349    pmulhw      mm1, [GOTOFF(ebx,PW_F1414)]
350    psubw       mm1, mm5                ; mm1=tmp12
351
352    movq        mm6, mm4
353    movq        mm7, mm0
354    psubw       mm4, mm5                ; mm4=tmp3
355    psubw       mm0, mm1                ; mm0=tmp2
356    paddw       mm6, mm5                ; mm6=tmp0
357    paddw       mm7, mm1                ; mm7=tmp1
358
359    movq        MMWORD [wk(1)], mm4     ; wk(1)=tmp3
360    movq        MMWORD [wk(0)], mm0     ; wk(0)=tmp2
361
362    ; -- Odd part
363
364    movq        mm2, MMWORD [MMBLOCK(1,0,esi,SIZEOF_JCOEF)]
365    movq        mm3, MMWORD [MMBLOCK(3,0,esi,SIZEOF_JCOEF)]
366    movq        mm5, MMWORD [MMBLOCK(5,0,esi,SIZEOF_JCOEF)]
367    movq        mm1, MMWORD [MMBLOCK(7,0,esi,SIZEOF_JCOEF)]
368
369    movq        mm4, mm2
370    movq        mm0, mm5
371    psubw       mm2, mm1                ; mm2=z12
372    psubw       mm5, mm3                ; mm5=z10
373    paddw       mm4, mm1                ; mm4=z11
374    paddw       mm0, mm3                ; mm0=z13
375
376    movq        mm1, mm5                ; mm1=z10(unscaled)
377    psllw       mm2, PRE_MULTIPLY_SCALE_BITS
378    psllw       mm5, PRE_MULTIPLY_SCALE_BITS
379
380    movq        mm3, mm4
381    psubw       mm4, mm0
382    paddw       mm3, mm0                ; mm3=tmp7
383
384    psllw       mm4, PRE_MULTIPLY_SCALE_BITS
385    pmulhw      mm4, [GOTOFF(ebx,PW_F1414)]  ; mm4=tmp11
386
387    ; To avoid overflow...
388    ;
389    ; (Original)
390    ; tmp12 = -2.613125930 * z10 + z5;
391    ;
392    ; (This implementation)
393    ; tmp12 = (-1.613125930 - 1) * z10 + z5;
394    ;       = -1.613125930 * z10 - z10 + z5;
395
396    movq        mm0, mm5
397    paddw       mm5, mm2
398    pmulhw      mm5, [GOTOFF(ebx,PW_F1847)]   ; mm5=z5
399    pmulhw      mm0, [GOTOFF(ebx,PW_MF1613)]
400    pmulhw      mm2, [GOTOFF(ebx,PW_F1082)]
401    psubw       mm0, mm1
402    psubw       mm2, mm5                ; mm2=tmp10
403    paddw       mm0, mm5                ; mm0=tmp12
404
405    ; -- Final output stage
406
407    psubw       mm0, mm3                ; mm0=tmp6
408    movq        mm1, mm6
409    movq        mm5, mm7
410    paddw       mm6, mm3                ; mm6=data0=(00 10 20 30)
411    paddw       mm7, mm0                ; mm7=data1=(01 11 21 31)
412    psraw       mm6, (PASS1_BITS+3)     ; descale
413    psraw       mm7, (PASS1_BITS+3)     ; descale
414    psubw       mm1, mm3                ; mm1=data7=(07 17 27 37)
415    psubw       mm5, mm0                ; mm5=data6=(06 16 26 36)
416    psraw       mm1, (PASS1_BITS+3)     ; descale
417    psraw       mm5, (PASS1_BITS+3)     ; descale
418    psubw       mm4, mm0                ; mm4=tmp5
419
420    packsswb    mm6, mm5                ; mm6=(00 10 20 30 06 16 26 36)
421    packsswb    mm7, mm1                ; mm7=(01 11 21 31 07 17 27 37)
422
423    movq        mm3, MMWORD [wk(0)]     ; mm3=tmp2
424    movq        mm0, MMWORD [wk(1)]     ; mm0=tmp3
425
426    paddw       mm2, mm4                ; mm2=tmp4
427    movq        mm5, mm3
428    movq        mm1, mm0
429    paddw       mm3, mm4                ; mm3=data2=(02 12 22 32)
430    paddw       mm0, mm2                ; mm0=data4=(04 14 24 34)
431    psraw       mm3, (PASS1_BITS+3)     ; descale
432    psraw       mm0, (PASS1_BITS+3)     ; descale
433    psubw       mm5, mm4                ; mm5=data5=(05 15 25 35)
434    psubw       mm1, mm2                ; mm1=data3=(03 13 23 33)
435    psraw       mm5, (PASS1_BITS+3)     ; descale
436    psraw       mm1, (PASS1_BITS+3)     ; descale
437
438    movq        mm4, [GOTOFF(ebx,PB_CENTERJSAMP)]  ; mm4=[PB_CENTERJSAMP]
439
440    packsswb    mm3, mm0                ; mm3=(02 12 22 32 04 14 24 34)
441    packsswb    mm1, mm5                ; mm1=(03 13 23 33 05 15 25 35)
442
443    paddb       mm6, mm4
444    paddb       mm7, mm4
445    paddb       mm3, mm4
446    paddb       mm1, mm4
447
448    movq        mm2, mm6                ; transpose coefficients(phase 1)
449    punpcklbw   mm6, mm7                ; mm6=(00 01 10 11 20 21 30 31)
450    punpckhbw   mm2, mm7                ; mm2=(06 07 16 17 26 27 36 37)
451    movq        mm0, mm3                ; transpose coefficients(phase 1)
452    punpcklbw   mm3, mm1                ; mm3=(02 03 12 13 22 23 32 33)
453    punpckhbw   mm0, mm1                ; mm0=(04 05 14 15 24 25 34 35)
454
455    movq        mm5, mm6                ; transpose coefficients(phase 2)
456    punpcklwd   mm6, mm3                ; mm6=(00 01 02 03 10 11 12 13)
457    punpckhwd   mm5, mm3                ; mm5=(20 21 22 23 30 31 32 33)
458    movq        mm4, mm0                ; transpose coefficients(phase 2)
459    punpcklwd   mm0, mm2                ; mm0=(04 05 06 07 14 15 16 17)
460    punpckhwd   mm4, mm2                ; mm4=(24 25 26 27 34 35 36 37)
461
462    movq        mm7, mm6                ; transpose coefficients(phase 3)
463    punpckldq   mm6, mm0                ; mm6=(00 01 02 03 04 05 06 07)
464    punpckhdq   mm7, mm0                ; mm7=(10 11 12 13 14 15 16 17)
465    movq        mm1, mm5                ; transpose coefficients(phase 3)
466    punpckldq   mm5, mm4                ; mm5=(20 21 22 23 24 25 26 27)
467    punpckhdq   mm1, mm4                ; mm1=(30 31 32 33 34 35 36 37)
468
469    pushpic     ebx                     ; save GOT address
470
471    mov         edx, JSAMPROW [edi+0*SIZEOF_JSAMPROW]
472    mov         ebx, JSAMPROW [edi+1*SIZEOF_JSAMPROW]
473    movq        MMWORD [edx+eax*SIZEOF_JSAMPLE], mm6
474    movq        MMWORD [ebx+eax*SIZEOF_JSAMPLE], mm7
475    mov         edx, JSAMPROW [edi+2*SIZEOF_JSAMPROW]
476    mov         ebx, JSAMPROW [edi+3*SIZEOF_JSAMPROW]
477    movq        MMWORD [edx+eax*SIZEOF_JSAMPLE], mm5
478    movq        MMWORD [ebx+eax*SIZEOF_JSAMPLE], mm1
479
480    poppic      ebx                     ; restore GOT address
481
482    add         esi, byte 4*SIZEOF_JCOEF     ; wsptr
483    add         edi, byte 4*SIZEOF_JSAMPROW
484    dec         ecx                          ; ctr
485    jnz         near .rowloop
486
487    emms                                ; empty MMX state
488
489    pop         edi
490    pop         esi
491;   pop         edx                     ; need not be preserved
492;   pop         ecx                     ; need not be preserved
493    pop         ebx
494    mov         esp, ebp                ; esp <- aligned ebp
495    pop         esp                     ; esp <- original ebp
496    pop         ebp
497    ret
498
499; For some reason, the OS X linker does not honor the request to align the
500; segment unless we do this.
501    align       32
502