summaryrefslogtreecommitdiffstats
path: root/media/libjpeg/simd/x86_64/jfdctfst-sse2.asm
blob: 2e1bfe6e8c2fc0489ed48be40306a1a2cb2bf6b7 (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
;
; jfdctfst.asm - fast integer FDCT (64-bit SSE2)
;
; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
; Copyright (C) 2009, 2016, D. R. Commander.
;
; 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 fast, not so accurate integer implementation of
; the forward DCT (Discrete Cosine Transform). The following code is
; based directly on the IJG's original jfdctfst.c; see the jfdctfst.c
; for more details.

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

; --------------------------------------------------------------------------

%define CONST_BITS  8  ; 14 is also OK.

%if CONST_BITS == 8
F_0_382 equ  98  ; FIX(0.382683433)
F_0_541 equ 139  ; FIX(0.541196100)
F_0_707 equ 181  ; FIX(0.707106781)
F_1_306 equ 334  ; FIX(1.306562965)
%else
; NASM cannot do compile-time arithmetic on floating-point constants.
%define DESCALE(x, n)  (((x) + (1 << ((n) - 1))) >> (n))
F_0_382 equ DESCALE( 410903207, 30 - CONST_BITS)  ; FIX(0.382683433)
F_0_541 equ DESCALE( 581104887, 30 - CONST_BITS)  ; FIX(0.541196100)
F_0_707 equ DESCALE( 759250124, 30 - CONST_BITS)  ; FIX(0.707106781)
F_1_306 equ DESCALE(1402911301, 30 - CONST_BITS)  ; FIX(1.306562965)
%endif

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

; PRE_MULTIPLY_SCALE_BITS <= 2 (to avoid overflow)
; CONST_BITS + CONST_SHIFT + PRE_MULTIPLY_SCALE_BITS == 16 (for pmulhw)

%define PRE_MULTIPLY_SCALE_BITS  2
%define CONST_SHIFT              (16 - PRE_MULTIPLY_SCALE_BITS - CONST_BITS)

    alignz      32
    GLOBAL_DATA(jconst_fdct_ifast_sse2)

EXTN(jconst_fdct_ifast_sse2):

PW_F0707 times 8 dw F_0_707 << CONST_SHIFT
PW_F0382 times 8 dw F_0_382 << CONST_SHIFT
PW_F0541 times 8 dw F_0_541 << CONST_SHIFT
PW_F1306 times 8 dw F_1_306 << CONST_SHIFT

    alignz      32

; --------------------------------------------------------------------------
    SECTION     SEG_TEXT
    BITS        64
;
; Perform the forward DCT on one block of samples.
;
; GLOBAL(void)
; jsimd_fdct_ifast_sse2(DCTELEM *data)
;

; r10 = DCTELEM *data

%define wk(i)   rbp - (WK_NUM - (i)) * SIZEOF_XMMWORD  ; xmmword wk[WK_NUM]
%define WK_NUM  2

    align       32
    GLOBAL_FUNCTION(jsimd_fdct_ifast_sse2)

EXTN(jsimd_fdct_ifast_sse2):
    push        rbp
    mov         rax, rsp                     ; rax = original rbp
    sub         rsp, byte 4
    and         rsp, byte (-SIZEOF_XMMWORD)  ; align to 128 bits
    mov         [rsp], rax
    mov         rbp, rsp                     ; rbp = aligned rbp
    lea         rsp, [wk(0)]
    collect_args 1

    ; ---- Pass 1: process rows.

    mov         rdx, r10                ; (DCTELEM *)

    movdqa      xmm0, XMMWORD [XMMBLOCK(0,0,rdx,SIZEOF_DCTELEM)]
    movdqa      xmm1, XMMWORD [XMMBLOCK(1,0,rdx,SIZEOF_DCTELEM)]
    movdqa      xmm2, XMMWORD [XMMBLOCK(2,0,rdx,SIZEOF_DCTELEM)]
    movdqa      xmm3, XMMWORD [XMMBLOCK(3,0,rdx,SIZEOF_DCTELEM)]

    ; xmm0=(00 01 02 03 04 05 06 07), xmm2=(20 21 22 23 24 25 26 27)
    ; xmm1=(10 11 12 13 14 15 16 17), xmm3=(30 31 32 33 34 35 36 37)

    movdqa      xmm4, xmm0              ; transpose coefficients(phase 1)
    punpcklwd   xmm0, xmm1              ; xmm0=(00 10 01 11 02 12 03 13)
    punpckhwd   xmm4, xmm1              ; xmm4=(04 14 05 15 06 16 07 17)
    movdqa      xmm5, xmm2              ; transpose coefficients(phase 1)
    punpcklwd   xmm2, xmm3              ; xmm2=(20 30 21 31 22 32 23 33)
    punpckhwd   xmm5, xmm3              ; xmm5=(24 34 25 35 26 36 27 37)

    movdqa      xmm6, XMMWORD [XMMBLOCK(4,0,rdx,SIZEOF_DCTELEM)]
    movdqa      xmm7, XMMWORD [XMMBLOCK(5,0,rdx,SIZEOF_DCTELEM)]
    movdqa      xmm1, XMMWORD [XMMBLOCK(6,0,rdx,SIZEOF_DCTELEM)]
    movdqa      xmm3, XMMWORD [XMMBLOCK(7,0,rdx,SIZEOF_DCTELEM)]

    ; xmm6=( 4 12 20 28 36 44 52 60), xmm1=( 6 14 22 30 38 46 54 62)
    ; xmm7=( 5 13 21 29 37 45 53 61), xmm3=( 7 15 23 31 39 47 55 63)

    movdqa      XMMWORD [wk(0)], xmm2   ; wk(0)=(20 30 21 31 22 32 23 33)
    movdqa      XMMWORD [wk(1)], xmm5   ; wk(1)=(24 34 25 35 26 36 27 37)

    movdqa      xmm2, xmm6              ; transpose coefficients(phase 1)
    punpcklwd   xmm6, xmm7              ; xmm6=(40 50 41 51 42 52 43 53)
    punpckhwd   xmm2, xmm7              ; xmm2=(44 54 45 55 46 56 47 57)
    movdqa      xmm5, xmm1              ; transpose coefficients(phase 1)
    punpcklwd   xmm1, xmm3              ; xmm1=(60 70 61 71 62 72 63 73)
    punpckhwd   xmm5, xmm3              ; xmm5=(64 74 65 75 66 76 67 77)

    movdqa      xmm7, xmm6              ; transpose coefficients(phase 2)
    punpckldq   xmm6, xmm1              ; xmm6=(40 50 60 70 41 51 61 71)
    punpckhdq   xmm7, xmm1              ; xmm7=(42 52 62 72 43 53 63 73)
    movdqa      xmm3, xmm2              ; transpose coefficients(phase 2)
    punpckldq   xmm2, xmm5              ; xmm2=(44 54 64 74 45 55 65 75)
    punpckhdq   xmm3, xmm5              ; xmm3=(46 56 66 76 47 57 67 77)

    movdqa      xmm1, XMMWORD [wk(0)]   ; xmm1=(20 30 21 31 22 32 23 33)
    movdqa      xmm5, XMMWORD [wk(1)]   ; xmm5=(24 34 25 35 26 36 27 37)
    movdqa      XMMWORD [wk(0)], xmm7   ; wk(0)=(42 52 62 72 43 53 63 73)
    movdqa      XMMWORD [wk(1)], xmm2   ; wk(1)=(44 54 64 74 45 55 65 75)

    movdqa      xmm7, xmm0              ; transpose coefficients(phase 2)
    punpckldq   xmm0, xmm1              ; xmm0=(00 10 20 30 01 11 21 31)
    punpckhdq   xmm7, xmm1              ; xmm7=(02 12 22 32 03 13 23 33)
    movdqa      xmm2, xmm4              ; transpose coefficients(phase 2)
    punpckldq   xmm4, xmm5              ; xmm4=(04 14 24 34 05 15 25 35)
    punpckhdq   xmm2, xmm5              ; xmm2=(06 16 26 36 07 17 27 37)

    movdqa      xmm1, xmm0              ; transpose coefficients(phase 3)
    punpcklqdq  xmm0, xmm6              ; xmm0=(00 10 20 30 40 50 60 70)=data0
    punpckhqdq  xmm1, xmm6              ; xmm1=(01 11 21 31 41 51 61 71)=data1
    movdqa      xmm5, xmm2              ; transpose coefficients(phase 3)
    punpcklqdq  xmm2, xmm3              ; xmm2=(06 16 26 36 46 56 66 76)=data6
    punpckhqdq  xmm5, xmm3              ; xmm5=(07 17 27 37 47 57 67 77)=data7

    movdqa      xmm6, xmm1
    movdqa      xmm3, xmm0
    psubw       xmm1, xmm2              ; xmm1=data1-data6=tmp6
    psubw       xmm0, xmm5              ; xmm0=data0-data7=tmp7
    paddw       xmm6, xmm2              ; xmm6=data1+data6=tmp1
    paddw       xmm3, xmm5              ; xmm3=data0+data7=tmp0

    movdqa      xmm2, XMMWORD [wk(0)]   ; xmm2=(42 52 62 72 43 53 63 73)
    movdqa      xmm5, XMMWORD [wk(1)]   ; xmm5=(44 54 64 74 45 55 65 75)
    movdqa      XMMWORD [wk(0)], xmm1   ; wk(0)=tmp6
    movdqa      XMMWORD [wk(1)], xmm0   ; wk(1)=tmp7

    movdqa      xmm1, xmm7              ; transpose coefficients(phase 3)
    punpcklqdq  xmm7, xmm2              ; xmm7=(02 12 22 32 42 52 62 72)=data2
    punpckhqdq  xmm1, xmm2              ; xmm1=(03 13 23 33 43 53 63 73)=data3
    movdqa      xmm0, xmm4              ; transpose coefficients(phase 3)
    punpcklqdq  xmm4, xmm5              ; xmm4=(04 14 24 34 44 54 64 74)=data4
    punpckhqdq  xmm0, xmm5              ; xmm0=(05 15 25 35 45 55 65 75)=data5

    movdqa      xmm2, xmm1
    movdqa      xmm5, xmm7
    paddw       xmm1, xmm4              ; xmm1=data3+data4=tmp3
    paddw       xmm7, xmm0              ; xmm7=data2+data5=tmp2
    psubw       xmm2, xmm4              ; xmm2=data3-data4=tmp4
    psubw       xmm5, xmm0              ; xmm5=data2-data5=tmp5

    ; -- Even part

    movdqa      xmm4, xmm3
    movdqa      xmm0, xmm6
    psubw       xmm3, xmm1              ; xmm3=tmp13
    psubw       xmm6, xmm7              ; xmm6=tmp12
    paddw       xmm4, xmm1              ; xmm4=tmp10
    paddw       xmm0, xmm7              ; xmm0=tmp11

    paddw       xmm6, xmm3
    psllw       xmm6, PRE_MULTIPLY_SCALE_BITS
    pmulhw      xmm6, [rel PW_F0707]    ; xmm6=z1

    movdqa      xmm1, xmm4
    movdqa      xmm7, xmm3
    psubw       xmm4, xmm0              ; xmm4=data4
    psubw       xmm3, xmm6              ; xmm3=data6
    paddw       xmm1, xmm0              ; xmm1=data0
    paddw       xmm7, xmm6              ; xmm7=data2

    movdqa      xmm0, XMMWORD [wk(0)]   ; xmm0=tmp6
    movdqa      xmm6, XMMWORD [wk(1)]   ; xmm6=tmp7
    movdqa      XMMWORD [wk(0)], xmm4   ; wk(0)=data4
    movdqa      XMMWORD [wk(1)], xmm3   ; wk(1)=data6

    ; -- Odd part

    paddw       xmm2, xmm5              ; xmm2=tmp10
    paddw       xmm5, xmm0              ; xmm5=tmp11
    paddw       xmm0, xmm6              ; xmm0=tmp12, xmm6=tmp7

    psllw       xmm2, PRE_MULTIPLY_SCALE_BITS
    psllw       xmm0, PRE_MULTIPLY_SCALE_BITS

    psllw       xmm5, PRE_MULTIPLY_SCALE_BITS
    pmulhw      xmm5, [rel PW_F0707]    ; xmm5=z3

    movdqa      xmm4, xmm2              ; xmm4=tmp10
    psubw       xmm2, xmm0
    pmulhw      xmm2, [rel PW_F0382]    ; xmm2=z5
    pmulhw      xmm4, [rel PW_F0541]    ; xmm4=MULTIPLY(tmp10,FIX_0_541196)
    pmulhw      xmm0, [rel PW_F1306]    ; xmm0=MULTIPLY(tmp12,FIX_1_306562)
    paddw       xmm4, xmm2              ; xmm4=z2
    paddw       xmm0, xmm2              ; xmm0=z4

    movdqa      xmm3, xmm6
    psubw       xmm6, xmm5              ; xmm6=z13
    paddw       xmm3, xmm5              ; xmm3=z11

    movdqa      xmm2, xmm6
    movdqa      xmm5, xmm3
    psubw       xmm6, xmm4              ; xmm6=data3
    psubw       xmm3, xmm0              ; xmm3=data7
    paddw       xmm2, xmm4              ; xmm2=data5
    paddw       xmm5, xmm0              ; xmm5=data1

    ; ---- Pass 2: process columns.

    ; xmm1=(00 10 20 30 40 50 60 70), xmm7=(02 12 22 32 42 52 62 72)
    ; xmm5=(01 11 21 31 41 51 61 71), xmm6=(03 13 23 33 43 53 63 73)

    movdqa      xmm4, xmm1              ; transpose coefficients(phase 1)
    punpcklwd   xmm1, xmm5              ; xmm1=(00 01 10 11 20 21 30 31)
    punpckhwd   xmm4, xmm5              ; xmm4=(40 41 50 51 60 61 70 71)
    movdqa      xmm0, xmm7              ; transpose coefficients(phase 1)
    punpcklwd   xmm7, xmm6              ; xmm7=(02 03 12 13 22 23 32 33)
    punpckhwd   xmm0, xmm6              ; xmm0=(42 43 52 53 62 63 72 73)

    movdqa      xmm5, XMMWORD [wk(0)]   ; xmm5=col4
    movdqa      xmm6, XMMWORD [wk(1)]   ; xmm6=col6

    ; xmm5=(04 14 24 34 44 54 64 74), xmm6=(06 16 26 36 46 56 66 76)
    ; xmm2=(05 15 25 35 45 55 65 75), xmm3=(07 17 27 37 47 57 67 77)

    movdqa      XMMWORD [wk(0)], xmm7   ; wk(0)=(02 03 12 13 22 23 32 33)
    movdqa      XMMWORD [wk(1)], xmm0   ; wk(1)=(42 43 52 53 62 63 72 73)

    movdqa      xmm7, xmm5              ; transpose coefficients(phase 1)
    punpcklwd   xmm5, xmm2              ; xmm5=(04 05 14 15 24 25 34 35)
    punpckhwd   xmm7, xmm2              ; xmm7=(44 45 54 55 64 65 74 75)
    movdqa      xmm0, xmm6              ; transpose coefficients(phase 1)
    punpcklwd   xmm6, xmm3              ; xmm6=(06 07 16 17 26 27 36 37)
    punpckhwd   xmm0, xmm3              ; xmm0=(46 47 56 57 66 67 76 77)

    movdqa      xmm2, xmm5              ; transpose coefficients(phase 2)
    punpckldq   xmm5, xmm6              ; xmm5=(04 05 06 07 14 15 16 17)
    punpckhdq   xmm2, xmm6              ; xmm2=(24 25 26 27 34 35 36 37)
    movdqa      xmm3, xmm7              ; transpose coefficients(phase 2)
    punpckldq   xmm7, xmm0              ; xmm7=(44 45 46 47 54 55 56 57)
    punpckhdq   xmm3, xmm0              ; xmm3=(64 65 66 67 74 75 76 77)

    movdqa      xmm6, XMMWORD [wk(0)]   ; xmm6=(02 03 12 13 22 23 32 33)
    movdqa      xmm0, XMMWORD [wk(1)]   ; xmm0=(42 43 52 53 62 63 72 73)
    movdqa      XMMWORD [wk(0)], xmm2   ; wk(0)=(24 25 26 27 34 35 36 37)
    movdqa      XMMWORD [wk(1)], xmm7   ; wk(1)=(44 45 46 47 54 55 56 57)

    movdqa      xmm2, xmm1              ; transpose coefficients(phase 2)
    punpckldq   xmm1, xmm6              ; xmm1=(00 01 02 03 10 11 12 13)
    punpckhdq   xmm2, xmm6              ; xmm2=(20 21 22 23 30 31 32 33)
    movdqa      xmm7, xmm4              ; transpose coefficients(phase 2)
    punpckldq   xmm4, xmm0              ; xmm4=(40 41 42 43 50 51 52 53)
    punpckhdq   xmm7, xmm0              ; xmm7=(60 61 62 63 70 71 72 73)

    movdqa      xmm6, xmm1              ; transpose coefficients(phase 3)
    punpcklqdq  xmm1, xmm5              ; xmm1=(00 01 02 03 04 05 06 07)=data0
    punpckhqdq  xmm6, xmm5              ; xmm6=(10 11 12 13 14 15 16 17)=data1
    movdqa      xmm0, xmm7              ; transpose coefficients(phase 3)
    punpcklqdq  xmm7, xmm3              ; xmm7=(60 61 62 63 64 65 66 67)=data6
    punpckhqdq  xmm0, xmm3              ; xmm0=(70 71 72 73 74 75 76 77)=data7

    movdqa      xmm5, xmm6
    movdqa      xmm3, xmm1
    psubw       xmm6, xmm7              ; xmm6=data1-data6=tmp6
    psubw       xmm1, xmm0              ; xmm1=data0-data7=tmp7
    paddw       xmm5, xmm7              ; xmm5=data1+data6=tmp1
    paddw       xmm3, xmm0              ; xmm3=data0+data7=tmp0

    movdqa      xmm7, XMMWORD [wk(0)]   ; xmm7=(24 25 26 27 34 35 36 37)
    movdqa      xmm0, XMMWORD [wk(1)]   ; xmm0=(44 45 46 47 54 55 56 57)
    movdqa      XMMWORD [wk(0)], xmm6   ; wk(0)=tmp6
    movdqa      XMMWORD [wk(1)], xmm1   ; wk(1)=tmp7

    movdqa      xmm6, xmm2              ; transpose coefficients(phase 3)
    punpcklqdq  xmm2, xmm7              ; xmm2=(20 21 22 23 24 25 26 27)=data2
    punpckhqdq  xmm6, xmm7              ; xmm6=(30 31 32 33 34 35 36 37)=data3
    movdqa      xmm1, xmm4              ; transpose coefficients(phase 3)
    punpcklqdq  xmm4, xmm0              ; xmm4=(40 41 42 43 44 45 46 47)=data4
    punpckhqdq  xmm1, xmm0              ; xmm1=(50 51 52 53 54 55 56 57)=data5

    movdqa      xmm7, xmm6
    movdqa      xmm0, xmm2
    paddw       xmm6, xmm4              ; xmm6=data3+data4=tmp3
    paddw       xmm2, xmm1              ; xmm2=data2+data5=tmp2
    psubw       xmm7, xmm4              ; xmm7=data3-data4=tmp4
    psubw       xmm0, xmm1              ; xmm0=data2-data5=tmp5

    ; -- Even part

    movdqa      xmm4, xmm3
    movdqa      xmm1, xmm5
    psubw       xmm3, xmm6              ; xmm3=tmp13
    psubw       xmm5, xmm2              ; xmm5=tmp12
    paddw       xmm4, xmm6              ; xmm4=tmp10
    paddw       xmm1, xmm2              ; xmm1=tmp11

    paddw       xmm5, xmm3
    psllw       xmm5, PRE_MULTIPLY_SCALE_BITS
    pmulhw      xmm5, [rel PW_F0707]    ; xmm5=z1

    movdqa      xmm6, xmm4
    movdqa      xmm2, xmm3
    psubw       xmm4, xmm1              ; xmm4=data4
    psubw       xmm3, xmm5              ; xmm3=data6
    paddw       xmm6, xmm1              ; xmm6=data0
    paddw       xmm2, xmm5              ; xmm2=data2

    movdqa      XMMWORD [XMMBLOCK(4,0,rdx,SIZEOF_DCTELEM)], xmm4
    movdqa      XMMWORD [XMMBLOCK(6,0,rdx,SIZEOF_DCTELEM)], xmm3
    movdqa      XMMWORD [XMMBLOCK(0,0,rdx,SIZEOF_DCTELEM)], xmm6
    movdqa      XMMWORD [XMMBLOCK(2,0,rdx,SIZEOF_DCTELEM)], xmm2

    ; -- Odd part

    movdqa      xmm1, XMMWORD [wk(0)]   ; xmm1=tmp6
    movdqa      xmm5, XMMWORD [wk(1)]   ; xmm5=tmp7

    paddw       xmm7, xmm0              ; xmm7=tmp10
    paddw       xmm0, xmm1              ; xmm0=tmp11
    paddw       xmm1, xmm5              ; xmm1=tmp12, xmm5=tmp7

    psllw       xmm7, PRE_MULTIPLY_SCALE_BITS
    psllw       xmm1, PRE_MULTIPLY_SCALE_BITS

    psllw       xmm0, PRE_MULTIPLY_SCALE_BITS
    pmulhw      xmm0, [rel PW_F0707]    ; xmm0=z3

    movdqa      xmm4, xmm7              ; xmm4=tmp10
    psubw       xmm7, xmm1
    pmulhw      xmm7, [rel PW_F0382]    ; xmm7=z5
    pmulhw      xmm4, [rel PW_F0541]    ; xmm4=MULTIPLY(tmp10,FIX_0_541196)
    pmulhw      xmm1, [rel PW_F1306]    ; xmm1=MULTIPLY(tmp12,FIX_1_306562)
    paddw       xmm4, xmm7              ; xmm4=z2
    paddw       xmm1, xmm7              ; xmm1=z4

    movdqa      xmm3, xmm5
    psubw       xmm5, xmm0              ; xmm5=z13
    paddw       xmm3, xmm0              ; xmm3=z11

    movdqa      xmm6, xmm5
    movdqa      xmm2, xmm3
    psubw       xmm5, xmm4              ; xmm5=data3
    psubw       xmm3, xmm1              ; xmm3=data7
    paddw       xmm6, xmm4              ; xmm6=data5
    paddw       xmm2, xmm1              ; xmm2=data1

    movdqa      XMMWORD [XMMBLOCK(3,0,rdx,SIZEOF_DCTELEM)], xmm5
    movdqa      XMMWORD [XMMBLOCK(7,0,rdx,SIZEOF_DCTELEM)], xmm3
    movdqa      XMMWORD [XMMBLOCK(5,0,rdx,SIZEOF_DCTELEM)], xmm6
    movdqa      XMMWORD [XMMBLOCK(1,0,rdx,SIZEOF_DCTELEM)], xmm2

    uncollect_args 1
    mov         rsp, rbp                ; rsp <- aligned rbp
    pop         rsp                     ; rsp <- original rbp
    pop         rbp
    ret

; For some reason, the OS X linker does not honor the request to align the
; segment unless we do this.
    align       32