• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1;
2; jfdctfst.asm - fast integer FDCT (SSE2)
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 forward DCT (Discrete Cosine Transform). The following code is
19; based directly on the IJG's original jfdctfst.c; see the jfdctfst.c
20; for more details.
21
22%include "jsimdext.inc"
23%include "jdct.inc"
24
25; --------------------------------------------------------------------------
26
27%define CONST_BITS  8  ; 14 is also OK.
28
29%if CONST_BITS == 8
30F_0_382 equ  98  ; FIX(0.382683433)
31F_0_541 equ 139  ; FIX(0.541196100)
32F_0_707 equ 181  ; FIX(0.707106781)
33F_1_306 equ 334  ; FIX(1.306562965)
34%else
35; NASM cannot do compile-time arithmetic on floating-point constants.
36%define DESCALE(x, n)  (((x) + (1 << ((n) - 1))) >> (n))
37F_0_382 equ DESCALE( 410903207, 30 - CONST_BITS)  ; FIX(0.382683433)
38F_0_541 equ DESCALE( 581104887, 30 - CONST_BITS)  ; FIX(0.541196100)
39F_0_707 equ DESCALE( 759250124, 30 - CONST_BITS)  ; FIX(0.707106781)
40F_1_306 equ DESCALE(1402911301, 30 - CONST_BITS)  ; FIX(1.306562965)
41%endif
42
43; --------------------------------------------------------------------------
44    SECTION     SEG_CONST
45
46; PRE_MULTIPLY_SCALE_BITS <= 2 (to avoid overflow)
47; CONST_BITS + CONST_SHIFT + PRE_MULTIPLY_SCALE_BITS == 16 (for pmulhw)
48
49%define PRE_MULTIPLY_SCALE_BITS  2
50%define CONST_SHIFT              (16 - PRE_MULTIPLY_SCALE_BITS - CONST_BITS)
51
52    alignz      32
53    GLOBAL_DATA(jconst_fdct_ifast_sse2)
54
55EXTN(jconst_fdct_ifast_sse2):
56
57PW_F0707 times 8 dw F_0_707 << CONST_SHIFT
58PW_F0382 times 8 dw F_0_382 << CONST_SHIFT
59PW_F0541 times 8 dw F_0_541 << CONST_SHIFT
60PW_F1306 times 8 dw F_1_306 << CONST_SHIFT
61
62    alignz      32
63
64; --------------------------------------------------------------------------
65    SECTION     SEG_TEXT
66    BITS        32
67;
68; Perform the forward DCT on one block of samples.
69;
70; GLOBAL(void)
71; jsimd_fdct_ifast_sse2(DCTELEM *data)
72;
73
74%define data(b)       (b) + 8           ; DCTELEM *data
75
76%define original_ebp  ebp + 0
77%define wk(i)         ebp - (WK_NUM - (i)) * SIZEOF_XMMWORD
78                                        ; xmmword wk[WK_NUM]
79%define WK_NUM        2
80
81    align       32
82    GLOBAL_FUNCTION(jsimd_fdct_ifast_sse2)
83
84EXTN(jsimd_fdct_ifast_sse2):
85    push        ebp
86    mov         eax, esp                     ; eax = original ebp
87    sub         esp, byte 4
88    and         esp, byte (-SIZEOF_XMMWORD)  ; align to 128 bits
89    mov         [esp], eax
90    mov         ebp, esp                     ; ebp = aligned ebp
91    lea         esp, [wk(0)]
92    pushpic     ebx
93;   push        ecx                     ; unused
94;   push        edx                     ; need not be preserved
95;   push        esi                     ; unused
96;   push        edi                     ; unused
97
98    get_GOT     ebx                     ; get GOT address
99
100    ; ---- Pass 1: process rows.
101
102    mov         edx, POINTER [data(eax)]  ; (DCTELEM *)
103
104    movdqa      xmm0, XMMWORD [XMMBLOCK(0,0,edx,SIZEOF_DCTELEM)]
105    movdqa      xmm1, XMMWORD [XMMBLOCK(1,0,edx,SIZEOF_DCTELEM)]
106    movdqa      xmm2, XMMWORD [XMMBLOCK(2,0,edx,SIZEOF_DCTELEM)]
107    movdqa      xmm3, XMMWORD [XMMBLOCK(3,0,edx,SIZEOF_DCTELEM)]
108
109    ; xmm0=(00 01 02 03 04 05 06 07), xmm2=(20 21 22 23 24 25 26 27)
110    ; xmm1=(10 11 12 13 14 15 16 17), xmm3=(30 31 32 33 34 35 36 37)
111
112    movdqa      xmm4, xmm0              ; transpose coefficients(phase 1)
113    punpcklwd   xmm0, xmm1              ; xmm0=(00 10 01 11 02 12 03 13)
114    punpckhwd   xmm4, xmm1              ; xmm4=(04 14 05 15 06 16 07 17)
115    movdqa      xmm5, xmm2              ; transpose coefficients(phase 1)
116    punpcklwd   xmm2, xmm3              ; xmm2=(20 30 21 31 22 32 23 33)
117    punpckhwd   xmm5, xmm3              ; xmm5=(24 34 25 35 26 36 27 37)
118
119    movdqa      xmm6, XMMWORD [XMMBLOCK(4,0,edx,SIZEOF_DCTELEM)]
120    movdqa      xmm7, XMMWORD [XMMBLOCK(5,0,edx,SIZEOF_DCTELEM)]
121    movdqa      xmm1, XMMWORD [XMMBLOCK(6,0,edx,SIZEOF_DCTELEM)]
122    movdqa      xmm3, XMMWORD [XMMBLOCK(7,0,edx,SIZEOF_DCTELEM)]
123
124    ; xmm6=( 4 12 20 28 36 44 52 60), xmm1=( 6 14 22 30 38 46 54 62)
125    ; xmm7=( 5 13 21 29 37 45 53 61), xmm3=( 7 15 23 31 39 47 55 63)
126
127    movdqa      XMMWORD [wk(0)], xmm2   ; wk(0)=(20 30 21 31 22 32 23 33)
128    movdqa      XMMWORD [wk(1)], xmm5   ; wk(1)=(24 34 25 35 26 36 27 37)
129
130    movdqa      xmm2, xmm6              ; transpose coefficients(phase 1)
131    punpcklwd   xmm6, xmm7              ; xmm6=(40 50 41 51 42 52 43 53)
132    punpckhwd   xmm2, xmm7              ; xmm2=(44 54 45 55 46 56 47 57)
133    movdqa      xmm5, xmm1              ; transpose coefficients(phase 1)
134    punpcklwd   xmm1, xmm3              ; xmm1=(60 70 61 71 62 72 63 73)
135    punpckhwd   xmm5, xmm3              ; xmm5=(64 74 65 75 66 76 67 77)
136
137    movdqa      xmm7, xmm6              ; transpose coefficients(phase 2)
138    punpckldq   xmm6, xmm1              ; xmm6=(40 50 60 70 41 51 61 71)
139    punpckhdq   xmm7, xmm1              ; xmm7=(42 52 62 72 43 53 63 73)
140    movdqa      xmm3, xmm2              ; transpose coefficients(phase 2)
141    punpckldq   xmm2, xmm5              ; xmm2=(44 54 64 74 45 55 65 75)
142    punpckhdq   xmm3, xmm5              ; xmm3=(46 56 66 76 47 57 67 77)
143
144    movdqa      xmm1, XMMWORD [wk(0)]   ; xmm1=(20 30 21 31 22 32 23 33)
145    movdqa      xmm5, XMMWORD [wk(1)]   ; xmm5=(24 34 25 35 26 36 27 37)
146    movdqa      XMMWORD [wk(0)], xmm7   ; wk(0)=(42 52 62 72 43 53 63 73)
147    movdqa      XMMWORD [wk(1)], xmm2   ; wk(1)=(44 54 64 74 45 55 65 75)
148
149    movdqa      xmm7, xmm0              ; transpose coefficients(phase 2)
150    punpckldq   xmm0, xmm1              ; xmm0=(00 10 20 30 01 11 21 31)
151    punpckhdq   xmm7, xmm1              ; xmm7=(02 12 22 32 03 13 23 33)
152    movdqa      xmm2, xmm4              ; transpose coefficients(phase 2)
153    punpckldq   xmm4, xmm5              ; xmm4=(04 14 24 34 05 15 25 35)
154    punpckhdq   xmm2, xmm5              ; xmm2=(06 16 26 36 07 17 27 37)
155
156    movdqa      xmm1, xmm0              ; transpose coefficients(phase 3)
157    punpcklqdq  xmm0, xmm6              ; xmm0=(00 10 20 30 40 50 60 70)=data0
158    punpckhqdq  xmm1, xmm6              ; xmm1=(01 11 21 31 41 51 61 71)=data1
159    movdqa      xmm5, xmm2              ; transpose coefficients(phase 3)
160    punpcklqdq  xmm2, xmm3              ; xmm2=(06 16 26 36 46 56 66 76)=data6
161    punpckhqdq  xmm5, xmm3              ; xmm5=(07 17 27 37 47 57 67 77)=data7
162
163    movdqa      xmm6, xmm1
164    movdqa      xmm3, xmm0
165    psubw       xmm1, xmm2              ; xmm1=data1-data6=tmp6
166    psubw       xmm0, xmm5              ; xmm0=data0-data7=tmp7
167    paddw       xmm6, xmm2              ; xmm6=data1+data6=tmp1
168    paddw       xmm3, xmm5              ; xmm3=data0+data7=tmp0
169
170    movdqa      xmm2, XMMWORD [wk(0)]   ; xmm2=(42 52 62 72 43 53 63 73)
171    movdqa      xmm5, XMMWORD [wk(1)]   ; xmm5=(44 54 64 74 45 55 65 75)
172    movdqa      XMMWORD [wk(0)], xmm1   ; wk(0)=tmp6
173    movdqa      XMMWORD [wk(1)], xmm0   ; wk(1)=tmp7
174
175    movdqa      xmm1, xmm7              ; transpose coefficients(phase 3)
176    punpcklqdq  xmm7, xmm2              ; xmm7=(02 12 22 32 42 52 62 72)=data2
177    punpckhqdq  xmm1, xmm2              ; xmm1=(03 13 23 33 43 53 63 73)=data3
178    movdqa      xmm0, xmm4              ; transpose coefficients(phase 3)
179    punpcklqdq  xmm4, xmm5              ; xmm4=(04 14 24 34 44 54 64 74)=data4
180    punpckhqdq  xmm0, xmm5              ; xmm0=(05 15 25 35 45 55 65 75)=data5
181
182    movdqa      xmm2, xmm1
183    movdqa      xmm5, xmm7
184    paddw       xmm1, xmm4              ; xmm1=data3+data4=tmp3
185    paddw       xmm7, xmm0              ; xmm7=data2+data5=tmp2
186    psubw       xmm2, xmm4              ; xmm2=data3-data4=tmp4
187    psubw       xmm5, xmm0              ; xmm5=data2-data5=tmp5
188
189    ; -- Even part
190
191    movdqa      xmm4, xmm3
192    movdqa      xmm0, xmm6
193    psubw       xmm3, xmm1              ; xmm3=tmp13
194    psubw       xmm6, xmm7              ; xmm6=tmp12
195    paddw       xmm4, xmm1              ; xmm4=tmp10
196    paddw       xmm0, xmm7              ; xmm0=tmp11
197
198    paddw       xmm6, xmm3
199    psllw       xmm6, PRE_MULTIPLY_SCALE_BITS
200    pmulhw      xmm6, [GOTOFF(ebx,PW_F0707)]  ; xmm6=z1
201
202    movdqa      xmm1, xmm4
203    movdqa      xmm7, xmm3
204    psubw       xmm4, xmm0              ; xmm4=data4
205    psubw       xmm3, xmm6              ; xmm3=data6
206    paddw       xmm1, xmm0              ; xmm1=data0
207    paddw       xmm7, xmm6              ; xmm7=data2
208
209    movdqa      xmm0, XMMWORD [wk(0)]   ; xmm0=tmp6
210    movdqa      xmm6, XMMWORD [wk(1)]   ; xmm6=tmp7
211    movdqa      XMMWORD [wk(0)], xmm4   ; wk(0)=data4
212    movdqa      XMMWORD [wk(1)], xmm3   ; wk(1)=data6
213
214    ; -- Odd part
215
216    paddw       xmm2, xmm5              ; xmm2=tmp10
217    paddw       xmm5, xmm0              ; xmm5=tmp11
218    paddw       xmm0, xmm6              ; xmm0=tmp12, xmm6=tmp7
219
220    psllw       xmm2, PRE_MULTIPLY_SCALE_BITS
221    psllw       xmm0, PRE_MULTIPLY_SCALE_BITS
222
223    psllw       xmm5, PRE_MULTIPLY_SCALE_BITS
224    pmulhw      xmm5, [GOTOFF(ebx,PW_F0707)]  ; xmm5=z3
225
226    movdqa      xmm4, xmm2                    ; xmm4=tmp10
227    psubw       xmm2, xmm0
228    pmulhw      xmm2, [GOTOFF(ebx,PW_F0382)]  ; xmm2=z5
229    pmulhw      xmm4, [GOTOFF(ebx,PW_F0541)]  ; xmm4=MULTIPLY(tmp10,FIX_0_541196)
230    pmulhw      xmm0, [GOTOFF(ebx,PW_F1306)]  ; xmm0=MULTIPLY(tmp12,FIX_1_306562)
231    paddw       xmm4, xmm2                    ; xmm4=z2
232    paddw       xmm0, xmm2                    ; xmm0=z4
233
234    movdqa      xmm3, xmm6
235    psubw       xmm6, xmm5              ; xmm6=z13
236    paddw       xmm3, xmm5              ; xmm3=z11
237
238    movdqa      xmm2, xmm6
239    movdqa      xmm5, xmm3
240    psubw       xmm6, xmm4              ; xmm6=data3
241    psubw       xmm3, xmm0              ; xmm3=data7
242    paddw       xmm2, xmm4              ; xmm2=data5
243    paddw       xmm5, xmm0              ; xmm5=data1
244
245    ; ---- Pass 2: process columns.
246
247;   mov         edx, POINTER [data(eax)]  ; (DCTELEM *)
248
249    ; xmm1=(00 10 20 30 40 50 60 70), xmm7=(02 12 22 32 42 52 62 72)
250    ; xmm5=(01 11 21 31 41 51 61 71), xmm6=(03 13 23 33 43 53 63 73)
251
252    movdqa      xmm4, xmm1              ; transpose coefficients(phase 1)
253    punpcklwd   xmm1, xmm5              ; xmm1=(00 01 10 11 20 21 30 31)
254    punpckhwd   xmm4, xmm5              ; xmm4=(40 41 50 51 60 61 70 71)
255    movdqa      xmm0, xmm7              ; transpose coefficients(phase 1)
256    punpcklwd   xmm7, xmm6              ; xmm7=(02 03 12 13 22 23 32 33)
257    punpckhwd   xmm0, xmm6              ; xmm0=(42 43 52 53 62 63 72 73)
258
259    movdqa      xmm5, XMMWORD [wk(0)]   ; xmm5=col4
260    movdqa      xmm6, XMMWORD [wk(1)]   ; xmm6=col6
261
262    ; xmm5=(04 14 24 34 44 54 64 74), xmm6=(06 16 26 36 46 56 66 76)
263    ; xmm2=(05 15 25 35 45 55 65 75), xmm3=(07 17 27 37 47 57 67 77)
264
265    movdqa      XMMWORD [wk(0)], xmm7   ; wk(0)=(02 03 12 13 22 23 32 33)
266    movdqa      XMMWORD [wk(1)], xmm0   ; wk(1)=(42 43 52 53 62 63 72 73)
267
268    movdqa      xmm7, xmm5              ; transpose coefficients(phase 1)
269    punpcklwd   xmm5, xmm2              ; xmm5=(04 05 14 15 24 25 34 35)
270    punpckhwd   xmm7, xmm2              ; xmm7=(44 45 54 55 64 65 74 75)
271    movdqa      xmm0, xmm6              ; transpose coefficients(phase 1)
272    punpcklwd   xmm6, xmm3              ; xmm6=(06 07 16 17 26 27 36 37)
273    punpckhwd   xmm0, xmm3              ; xmm0=(46 47 56 57 66 67 76 77)
274
275    movdqa      xmm2, xmm5              ; transpose coefficients(phase 2)
276    punpckldq   xmm5, xmm6              ; xmm5=(04 05 06 07 14 15 16 17)
277    punpckhdq   xmm2, xmm6              ; xmm2=(24 25 26 27 34 35 36 37)
278    movdqa      xmm3, xmm7              ; transpose coefficients(phase 2)
279    punpckldq   xmm7, xmm0              ; xmm7=(44 45 46 47 54 55 56 57)
280    punpckhdq   xmm3, xmm0              ; xmm3=(64 65 66 67 74 75 76 77)
281
282    movdqa      xmm6, XMMWORD [wk(0)]   ; xmm6=(02 03 12 13 22 23 32 33)
283    movdqa      xmm0, XMMWORD [wk(1)]   ; xmm0=(42 43 52 53 62 63 72 73)
284    movdqa      XMMWORD [wk(0)], xmm2   ; wk(0)=(24 25 26 27 34 35 36 37)
285    movdqa      XMMWORD [wk(1)], xmm7   ; wk(1)=(44 45 46 47 54 55 56 57)
286
287    movdqa      xmm2, xmm1              ; transpose coefficients(phase 2)
288    punpckldq   xmm1, xmm6              ; xmm1=(00 01 02 03 10 11 12 13)
289    punpckhdq   xmm2, xmm6              ; xmm2=(20 21 22 23 30 31 32 33)
290    movdqa      xmm7, xmm4              ; transpose coefficients(phase 2)
291    punpckldq   xmm4, xmm0              ; xmm4=(40 41 42 43 50 51 52 53)
292    punpckhdq   xmm7, xmm0              ; xmm7=(60 61 62 63 70 71 72 73)
293
294    movdqa      xmm6, xmm1              ; transpose coefficients(phase 3)
295    punpcklqdq  xmm1, xmm5              ; xmm1=(00 01 02 03 04 05 06 07)=data0
296    punpckhqdq  xmm6, xmm5              ; xmm6=(10 11 12 13 14 15 16 17)=data1
297    movdqa      xmm0, xmm7              ; transpose coefficients(phase 3)
298    punpcklqdq  xmm7, xmm3              ; xmm7=(60 61 62 63 64 65 66 67)=data6
299    punpckhqdq  xmm0, xmm3              ; xmm0=(70 71 72 73 74 75 76 77)=data7
300
301    movdqa      xmm5, xmm6
302    movdqa      xmm3, xmm1
303    psubw       xmm6, xmm7              ; xmm6=data1-data6=tmp6
304    psubw       xmm1, xmm0              ; xmm1=data0-data7=tmp7
305    paddw       xmm5, xmm7              ; xmm5=data1+data6=tmp1
306    paddw       xmm3, xmm0              ; xmm3=data0+data7=tmp0
307
308    movdqa      xmm7, XMMWORD [wk(0)]   ; xmm7=(24 25 26 27 34 35 36 37)
309    movdqa      xmm0, XMMWORD [wk(1)]   ; xmm0=(44 45 46 47 54 55 56 57)
310    movdqa      XMMWORD [wk(0)], xmm6   ; wk(0)=tmp6
311    movdqa      XMMWORD [wk(1)], xmm1   ; wk(1)=tmp7
312
313    movdqa      xmm6, xmm2              ; transpose coefficients(phase 3)
314    punpcklqdq  xmm2, xmm7              ; xmm2=(20 21 22 23 24 25 26 27)=data2
315    punpckhqdq  xmm6, xmm7              ; xmm6=(30 31 32 33 34 35 36 37)=data3
316    movdqa      xmm1, xmm4              ; transpose coefficients(phase 3)
317    punpcklqdq  xmm4, xmm0              ; xmm4=(40 41 42 43 44 45 46 47)=data4
318    punpckhqdq  xmm1, xmm0              ; xmm1=(50 51 52 53 54 55 56 57)=data5
319
320    movdqa      xmm7, xmm6
321    movdqa      xmm0, xmm2
322    paddw       xmm6, xmm4              ; xmm6=data3+data4=tmp3
323    paddw       xmm2, xmm1              ; xmm2=data2+data5=tmp2
324    psubw       xmm7, xmm4              ; xmm7=data3-data4=tmp4
325    psubw       xmm0, xmm1              ; xmm0=data2-data5=tmp5
326
327    ; -- Even part
328
329    movdqa      xmm4, xmm3
330    movdqa      xmm1, xmm5
331    psubw       xmm3, xmm6              ; xmm3=tmp13
332    psubw       xmm5, xmm2              ; xmm5=tmp12
333    paddw       xmm4, xmm6              ; xmm4=tmp10
334    paddw       xmm1, xmm2              ; xmm1=tmp11
335
336    paddw       xmm5, xmm3
337    psllw       xmm5, PRE_MULTIPLY_SCALE_BITS
338    pmulhw      xmm5, [GOTOFF(ebx,PW_F0707)]  ; xmm5=z1
339
340    movdqa      xmm6, xmm4
341    movdqa      xmm2, xmm3
342    psubw       xmm4, xmm1              ; xmm4=data4
343    psubw       xmm3, xmm5              ; xmm3=data6
344    paddw       xmm6, xmm1              ; xmm6=data0
345    paddw       xmm2, xmm5              ; xmm2=data2
346
347    movdqa      XMMWORD [XMMBLOCK(4,0,edx,SIZEOF_DCTELEM)], xmm4
348    movdqa      XMMWORD [XMMBLOCK(6,0,edx,SIZEOF_DCTELEM)], xmm3
349    movdqa      XMMWORD [XMMBLOCK(0,0,edx,SIZEOF_DCTELEM)], xmm6
350    movdqa      XMMWORD [XMMBLOCK(2,0,edx,SIZEOF_DCTELEM)], xmm2
351
352    ; -- Odd part
353
354    movdqa      xmm1, XMMWORD [wk(0)]   ; xmm1=tmp6
355    movdqa      xmm5, XMMWORD [wk(1)]   ; xmm5=tmp7
356
357    paddw       xmm7, xmm0              ; xmm7=tmp10
358    paddw       xmm0, xmm1              ; xmm0=tmp11
359    paddw       xmm1, xmm5              ; xmm1=tmp12, xmm5=tmp7
360
361    psllw       xmm7, PRE_MULTIPLY_SCALE_BITS
362    psllw       xmm1, PRE_MULTIPLY_SCALE_BITS
363
364    psllw       xmm0, PRE_MULTIPLY_SCALE_BITS
365    pmulhw      xmm0, [GOTOFF(ebx,PW_F0707)]  ; xmm0=z3
366
367    movdqa      xmm4, xmm7                    ; xmm4=tmp10
368    psubw       xmm7, xmm1
369    pmulhw      xmm7, [GOTOFF(ebx,PW_F0382)]  ; xmm7=z5
370    pmulhw      xmm4, [GOTOFF(ebx,PW_F0541)]  ; xmm4=MULTIPLY(tmp10,FIX_0_541196)
371    pmulhw      xmm1, [GOTOFF(ebx,PW_F1306)]  ; xmm1=MULTIPLY(tmp12,FIX_1_306562)
372    paddw       xmm4, xmm7                    ; xmm4=z2
373    paddw       xmm1, xmm7                    ; xmm1=z4
374
375    movdqa      xmm3, xmm5
376    psubw       xmm5, xmm0              ; xmm5=z13
377    paddw       xmm3, xmm0              ; xmm3=z11
378
379    movdqa      xmm6, xmm5
380    movdqa      xmm2, xmm3
381    psubw       xmm5, xmm4              ; xmm5=data3
382    psubw       xmm3, xmm1              ; xmm3=data7
383    paddw       xmm6, xmm4              ; xmm6=data5
384    paddw       xmm2, xmm1              ; xmm2=data1
385
386    movdqa      XMMWORD [XMMBLOCK(3,0,edx,SIZEOF_DCTELEM)], xmm5
387    movdqa      XMMWORD [XMMBLOCK(7,0,edx,SIZEOF_DCTELEM)], xmm3
388    movdqa      XMMWORD [XMMBLOCK(5,0,edx,SIZEOF_DCTELEM)], xmm6
389    movdqa      XMMWORD [XMMBLOCK(1,0,edx,SIZEOF_DCTELEM)], xmm2
390
391;   pop         edi                     ; unused
392;   pop         esi                     ; unused
393;   pop         edx                     ; need not be preserved
394;   pop         ecx                     ; unused
395    poppic      ebx
396    mov         esp, ebp                ; esp <- aligned ebp
397    pop         esp                     ; esp <- original ebp
398    pop         ebp
399    ret
400
401; For some reason, the OS X linker does not honor the request to align the
402; segment unless we do this.
403    align       32
404