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idct_altivec.c
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1 /*
2  * Copyright (c) 2001 Michel Lespinasse
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /*
22  * NOTE: This code is based on GPL code from the libmpeg2 project. The
23  * author, Michel Lespinasses, has given explicit permission to release
24  * under LGPL as part of FFmpeg.
25  */
26 
27 /*
28  * FFmpeg integration by Dieter Shirley
29  *
30  * This file is a direct copy of the AltiVec IDCT module from the libmpeg2
31  * project. I've deleted all of the libmpeg2-specific code, renamed the
32  * functions and reordered the function parameters. The only change to the
33  * IDCT function itself was to factor out the partial transposition, and to
34  * perform a full transpose at the end of the function.
35  */
36 
37 
38 #include <stdlib.h> /* malloc(), free() */
39 #include <string.h>
40 #include "config.h"
41 #if HAVE_ALTIVEC_H
42 #include <altivec.h>
43 #endif
44 #include "libavutil/ppc/types_altivec.h"
45 #include "libavcodec/dsputil.h"
46 #include "dsputil_altivec.h"
47 
48 #define IDCT_HALF \
49  /* 1st stage */ \
50  t1 = vec_mradds (a1, vx7, vx1 ); \
51  t8 = vec_mradds (a1, vx1, vec_subs (zero, vx7)); \
52  t7 = vec_mradds (a2, vx5, vx3); \
53  t3 = vec_mradds (ma2, vx3, vx5); \
54  \
55  /* 2nd stage */ \
56  t5 = vec_adds (vx0, vx4); \
57  t0 = vec_subs (vx0, vx4); \
58  t2 = vec_mradds (a0, vx6, vx2); \
59  t4 = vec_mradds (a0, vx2, vec_subs (zero, vx6)); \
60  t6 = vec_adds (t8, t3); \
61  t3 = vec_subs (t8, t3); \
62  t8 = vec_subs (t1, t7); \
63  t1 = vec_adds (t1, t7); \
64  \
65  /* 3rd stage */ \
66  t7 = vec_adds (t5, t2); \
67  t2 = vec_subs (t5, t2); \
68  t5 = vec_adds (t0, t4); \
69  t0 = vec_subs (t0, t4); \
70  t4 = vec_subs (t8, t3); \
71  t3 = vec_adds (t8, t3); \
72  \
73  /* 4th stage */ \
74  vy0 = vec_adds (t7, t1); \
75  vy7 = vec_subs (t7, t1); \
76  vy1 = vec_mradds (c4, t3, t5); \
77  vy6 = vec_mradds (mc4, t3, t5); \
78  vy2 = vec_mradds (c4, t4, t0); \
79  vy5 = vec_mradds (mc4, t4, t0); \
80  vy3 = vec_adds (t2, t6); \
81  vy4 = vec_subs (t2, t6);
82 
83 
84 #define IDCT \
85  vec_s16 vx0, vx1, vx2, vx3, vx4, vx5, vx6, vx7; \
86  vec_s16 vy0, vy1, vy2, vy3, vy4, vy5, vy6, vy7; \
87  vec_s16 a0, a1, a2, ma2, c4, mc4, zero, bias; \
88  vec_s16 t0, t1, t2, t3, t4, t5, t6, t7, t8; \
89  vec_u16 shift; \
90  \
91  c4 = vec_splat (constants[0], 0); \
92  a0 = vec_splat (constants[0], 1); \
93  a1 = vec_splat (constants[0], 2); \
94  a2 = vec_splat (constants[0], 3); \
95  mc4 = vec_splat (constants[0], 4); \
96  ma2 = vec_splat (constants[0], 5); \
97  bias = (vec_s16)vec_splat ((vec_s32)constants[0], 3); \
98  \
99  zero = vec_splat_s16 (0); \
100  shift = vec_splat_u16 (4); \
101  \
102  vx0 = vec_mradds (vec_sl (block[0], shift), constants[1], zero); \
103  vx1 = vec_mradds (vec_sl (block[1], shift), constants[2], zero); \
104  vx2 = vec_mradds (vec_sl (block[2], shift), constants[3], zero); \
105  vx3 = vec_mradds (vec_sl (block[3], shift), constants[4], zero); \
106  vx4 = vec_mradds (vec_sl (block[4], shift), constants[1], zero); \
107  vx5 = vec_mradds (vec_sl (block[5], shift), constants[4], zero); \
108  vx6 = vec_mradds (vec_sl (block[6], shift), constants[3], zero); \
109  vx7 = vec_mradds (vec_sl (block[7], shift), constants[2], zero); \
110  \
111  IDCT_HALF \
112  \
113  vx0 = vec_mergeh (vy0, vy4); \
114  vx1 = vec_mergel (vy0, vy4); \
115  vx2 = vec_mergeh (vy1, vy5); \
116  vx3 = vec_mergel (vy1, vy5); \
117  vx4 = vec_mergeh (vy2, vy6); \
118  vx5 = vec_mergel (vy2, vy6); \
119  vx6 = vec_mergeh (vy3, vy7); \
120  vx7 = vec_mergel (vy3, vy7); \
121  \
122  vy0 = vec_mergeh (vx0, vx4); \
123  vy1 = vec_mergel (vx0, vx4); \
124  vy2 = vec_mergeh (vx1, vx5); \
125  vy3 = vec_mergel (vx1, vx5); \
126  vy4 = vec_mergeh (vx2, vx6); \
127  vy5 = vec_mergel (vx2, vx6); \
128  vy6 = vec_mergeh (vx3, vx7); \
129  vy7 = vec_mergel (vx3, vx7); \
130  \
131  vx0 = vec_adds (vec_mergeh (vy0, vy4), bias); \
132  vx1 = vec_mergel (vy0, vy4); \
133  vx2 = vec_mergeh (vy1, vy5); \
134  vx3 = vec_mergel (vy1, vy5); \
135  vx4 = vec_mergeh (vy2, vy6); \
136  vx5 = vec_mergel (vy2, vy6); \
137  vx6 = vec_mergeh (vy3, vy7); \
138  vx7 = vec_mergel (vy3, vy7); \
139  \
140  IDCT_HALF \
141  \
142  shift = vec_splat_u16 (6); \
143  vx0 = vec_sra (vy0, shift); \
144  vx1 = vec_sra (vy1, shift); \
145  vx2 = vec_sra (vy2, shift); \
146  vx3 = vec_sra (vy3, shift); \
147  vx4 = vec_sra (vy4, shift); \
148  vx5 = vec_sra (vy5, shift); \
149  vx6 = vec_sra (vy6, shift); \
150  vx7 = vec_sra (vy7, shift);
151 
152 
153 static const vec_s16 constants[5] = {
154  {23170, 13573, 6518, 21895, -23170, -21895, 32, 31},
155  {16384, 22725, 21407, 19266, 16384, 19266, 21407, 22725},
156  {22725, 31521, 29692, 26722, 22725, 26722, 29692, 31521},
157  {21407, 29692, 27969, 25172, 21407, 25172, 27969, 29692},
158  {19266, 26722, 25172, 22654, 19266, 22654, 25172, 26722}
159 };
160 
161 void ff_idct_put_altivec(uint8_t* dest, int stride, int16_t *blk)
162 {
163  vec_s16 *block = (vec_s16*)blk;
164  vec_u8 tmp;
165 
166  IDCT
167 
168 #define COPY(dest,src) \
169  tmp = vec_packsu (src, src); \
170  vec_ste ((vec_u32)tmp, 0, (unsigned int *)dest); \
171  vec_ste ((vec_u32)tmp, 4, (unsigned int *)dest);
172 
173  COPY (dest, vx0) dest += stride;
174  COPY (dest, vx1) dest += stride;
175  COPY (dest, vx2) dest += stride;
176  COPY (dest, vx3) dest += stride;
177  COPY (dest, vx4) dest += stride;
178  COPY (dest, vx5) dest += stride;
179  COPY (dest, vx6) dest += stride;
180  COPY (dest, vx7)
181 }
182 
183 void ff_idct_add_altivec(uint8_t* dest, int stride, int16_t *blk)
184 {
185  vec_s16 *block = (vec_s16*)blk;
186  vec_u8 tmp;
187  vec_s16 tmp2, tmp3;
188  vec_u8 perm0;
189  vec_u8 perm1;
190  vec_u8 p0, p1, p;
191 
192  IDCT
193 
194  p0 = vec_lvsl (0, dest);
195  p1 = vec_lvsl (stride, dest);
196  p = vec_splat_u8 (-1);
197  perm0 = vec_mergeh (p, p0);
198  perm1 = vec_mergeh (p, p1);
199 
200 #define ADD(dest,src,perm) \
201  /* *(uint64_t *)&tmp = *(uint64_t *)dest; */ \
202  tmp = vec_ld (0, dest); \
203  tmp2 = (vec_s16)vec_perm (tmp, (vec_u8)zero, perm); \
204  tmp3 = vec_adds (tmp2, src); \
205  tmp = vec_packsu (tmp3, tmp3); \
206  vec_ste ((vec_u32)tmp, 0, (unsigned int *)dest); \
207  vec_ste ((vec_u32)tmp, 4, (unsigned int *)dest);
208 
209  ADD (dest, vx0, perm0) dest += stride;
210  ADD (dest, vx1, perm1) dest += stride;
211  ADD (dest, vx2, perm0) dest += stride;
212  ADD (dest, vx3, perm1) dest += stride;
213  ADD (dest, vx4, perm0) dest += stride;
214  ADD (dest, vx5, perm1) dest += stride;
215  ADD (dest, vx6, perm0) dest += stride;
216  ADD (dest, vx7, perm1)
217 }
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