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iirfilter_mips.c
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1 /*
2  * Copyright (c) 2012
3  * MIPS Technologies, Inc., California.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  * notice, this list of conditions and the following disclaimer in the
12  * documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the MIPS Technologies, Inc., nor the names of its
14  * contributors may be used to endorse or promote products derived from
15  * this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE MIPS TECHNOLOGIES, INC. ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE MIPS TECHNOLOGIES, INC. BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * Author: Bojan Zivkovic (bojan@mips.com)
30  *
31  * IIR filter optimized for MIPS floating-point architecture
32  *
33  * This file is part of FFmpeg.
34  *
35  * FFmpeg is free software; you can redistribute it and/or
36  * modify it under the terms of the GNU Lesser General Public
37  * License as published by the Free Software Foundation; either
38  * version 2.1 of the License, or (at your option) any later version.
39  *
40  * FFmpeg is distributed in the hope that it will be useful,
41  * but WITHOUT ANY WARRANTY; without even the implied warranty of
42  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
43  * Lesser General Public License for more details.
44  *
45  * You should have received a copy of the GNU Lesser General Public
46  * License along with FFmpeg; if not, write to the Free Software
47  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
48  */
49 
50  /**
51  * @file
52  * Reference: libavcodec/iirfilter.c
53  */
54 
55 #include "libavcodec/iirfilter.h"
56 
57 #if HAVE_INLINE_ASM
58 typedef struct FFIIRFilterCoeffs {
59  int order;
60  float gain;
61  int *cx;
62  float *cy;
64 
65 typedef struct FFIIRFilterState {
66  float x[1];
68 
69 static void ff_iir_filter_flt_mips(const struct FFIIRFilterCoeffs *c,
70  struct FFIIRFilterState *s, int size,
71  const float *src, int sstep, float *dst, int dstep)
72 {
73  if (c->order == 2) {
74  int i;
75  const float *src0 = src;
76  float *dst0 = dst;
77  for (i = 0; i < size; i++) {
78  float in = *src0 * c->gain + s->x[0] * c->cy[0] + s->x[1] * c->cy[1];
79  *dst0 = s->x[0] + in + s->x[1] * c->cx[1];
80  s->x[0] = s->x[1];
81  s->x[1] = in;
82  src0 += sstep;
83  dst0 += dstep;
84  }
85  } else if (c->order == 4) {
86  int i;
87  const float *src0 = src;
88  float *dst0 = dst;
89  float four = 4.0;
90  float six = 6.0;
91  for (i = 0; i < size; i += 4) {
92  float in1, in2, in3, in4;
93  float res1, res2, res3, res4;
94  float *x = s->x;
95  float *cy = c->cy;
96  float gain = c->gain;
97  float src0_0 = src0[0 ];
98  float src0_1 = src0[sstep ];
99  float src0_2 = src0[2*sstep];
100  float src0_3 = src0[3*sstep];
101 
102  __asm__ volatile (
103  "lwc1 $f0, 0(%[cy]) \n\t"
104  "lwc1 $f4, 0(%[x]) \n\t"
105  "lwc1 $f5, 4(%[x]) \n\t"
106  "lwc1 $f6, 8(%[x]) \n\t"
107  "lwc1 $f7, 12(%[x]) \n\t"
108  "mul.s %[in1], %[src0_0], %[gain] \n\t"
109  "mul.s %[in2], %[src0_1], %[gain] \n\t"
110  "mul.s %[in3], %[src0_2], %[gain] \n\t"
111  "mul.s %[in4], %[src0_3], %[gain] \n\t"
112  "lwc1 $f1, 4(%[cy]) \n\t"
113  "madd.s %[in1], %[in1], $f0, $f4 \n\t"
114  "madd.s %[in2], %[in2], $f0, $f5 \n\t"
115  "madd.s %[in3], %[in3], $f0, $f6 \n\t"
116  "madd.s %[in4], %[in4], $f0, $f7 \n\t"
117  "lwc1 $f2, 8(%[cy]) \n\t"
118  "madd.s %[in1], %[in1], $f1, $f5 \n\t"
119  "madd.s %[in2], %[in2], $f1, $f6 \n\t"
120  "madd.s %[in3], %[in3], $f1, $f7 \n\t"
121  "lwc1 $f3, 12(%[cy]) \n\t"
122  "add.s $f8, $f5, $f7 \n\t"
123  "madd.s %[in1], %[in1], $f2, $f6 \n\t"
124  "madd.s %[in2], %[in2], $f2, $f7 \n\t"
125  "mul.s $f9, $f6, %[six] \n\t"
126  "mul.s $f10, $f7, %[six] \n\t"
127  "madd.s %[in1], %[in1], $f3, $f7 \n\t"
128  "madd.s %[in2], %[in2], $f3, %[in1] \n\t"
129  "madd.s %[in3], %[in3], $f2, %[in1] \n\t"
130  "madd.s %[in4], %[in4], $f1, %[in1] \n\t"
131  "add.s %[res1], $f4, %[in1] \n\t"
132  "swc1 %[in1], 0(%[x]) \n\t"
133  "add.s $f0, $f6, %[in1] \n\t"
134  "madd.s %[in3], %[in3], $f3, %[in2] \n\t"
135  "madd.s %[in4], %[in4], $f2, %[in2] \n\t"
136  "add.s %[res2], $f5, %[in2] \n\t"
137  "madd.s %[res1], %[res1], $f8, %[four] \n\t"
138  "add.s $f8, $f7, %[in2] \n\t"
139  "swc1 %[in2], 4(%[x]) \n\t"
140  "madd.s %[in4], %[in4], $f3, %[in3] \n\t"
141  "add.s %[res3], $f6, %[in3] \n\t"
142  "add.s %[res1], %[res1], $f9 \n\t"
143  "madd.s %[res2], %[res2], $f0, %[four] \n\t"
144  "swc1 %[in3], 8(%[x]) \n\t"
145  "add.s %[res4], $f7, %[in4] \n\t"
146  "madd.s %[res3], %[res3], $f8, %[four] \n\t"
147  "swc1 %[in4], 12(%[x]) \n\t"
148  "add.s %[res2], %[res2], $f10 \n\t"
149  "add.s $f8, %[in1], %[in3] \n\t"
150  "madd.s %[res3], %[res3], %[in1], %[six] \n\t"
151  "madd.s %[res4], %[res4], $f8, %[four] \n\t"
152  "madd.s %[res4], %[res4], %[in2], %[six] \n\t"
153 
154  : [in1]"=&f"(in1), [in2]"=&f"(in2),
155  [in3]"=&f"(in3), [in4]"=&f"(in4),
156  [res1]"=&f"(res1), [res2]"=&f"(res2),
157  [res3]"=&f"(res3), [res4]"=&f"(res4)
158  : [src0_0]"f"(src0_0), [src0_1]"f"(src0_1),
159  [src0_2]"f"(src0_2), [src0_3]"f"(src0_3),
160  [gain]"f"(gain), [x]"r"(x), [cy]"r"(cy),
161  [four]"f"(four), [six]"f"(six)
162  : "$f0", "$f1", "$f2", "$f3",
163  "$f4", "$f5", "$f6", "$f7",
164  "$f8", "$f9", "$f10",
165  "memory"
166  );
167 
168  dst0[0 ] = res1;
169  dst0[sstep ] = res2;
170  dst0[2*sstep] = res3;
171  dst0[3*sstep] = res4;
172 
173  src0 += 4*sstep;
174  dst0 += 4*dstep;
175  }
176  } else {
177  int i;
178  const float *src0 = src;
179  float *dst0 = dst;
180  for (i = 0; i < size; i++) {
181  int j;
182  float in, res;
183  in = *src0 * c->gain;
184  for(j = 0; j < c->order; j++)
185  in += c->cy[j] * s->x[j];
186  res = s->x[0] + in + s->x[c->order >> 1] * c->cx[c->order >> 1];
187  for(j = 1; j < c->order >> 1; j++)
188  res += (s->x[j] + s->x[c->order - j]) * c->cx[j];
189  for(j = 0; j < c->order - 1; j++)
190  s->x[j] = s->x[j + 1];
191  *dst0 = res;
192  s->x[c->order - 1] = in;
193  src0 += sstep;
194  dst0 += dstep;
195  }
196  }
197 }
198 #endif /* HAVE_INLINE_ASM */
199 
201 #if HAVE_INLINE_ASM
202  f->filter_flt = ff_iir_filter_flt_mips;
203 #endif /* HAVE_INLINE_ASM */
204 }