FFmpeg
celp_math_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: Nedeljko Babic (nbabic@mips.com)
30  *
31  * Math operations optimized for MIPS
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/celp_math.c
53  */
54 #include "config.h"
55 #include "libavcodec/celp_math.h"
56 #include "libavutil/mips/asmdefs.h"
57 
58 #if HAVE_INLINE_ASM
59 #if !HAVE_MIPS32R6 && !HAVE_MIPS64R6
60 static float ff_dot_productf_mips(const float* a, const float* b,
61  int length)
62 {
63  float sum;
64  const float* a_end = a + length;
65 
66  __asm__ volatile (
67  "mtc1 $zero, %[sum] \n\t"
68  "blez %[length], ff_dot_productf_end%= \n\t"
69  "ff_dot_productf_madd%=: \n\t"
70  "lwc1 $f2, 0(%[a]) \n\t"
71  "lwc1 $f1, 0(%[b]) \n\t"
72  PTR_ADDIU "%[a], %[a], 4 \n\t"
73  PTR_ADDIU "%[b], %[b], 4 \n\t"
74  "madd.s %[sum], %[sum], $f1, $f2 \n\t"
75  "bne %[a], %[a_end], ff_dot_productf_madd%= \n\t"
76  "ff_dot_productf_end%=: \n\t"
77 
78  : [sum] "=&f" (sum), [a] "+r" (a), [b] "+r" (b)
79  : [a_end]"r"(a_end), [length] "r" (length)
80  : "$f1", "$f2", "memory"
81  );
82  return sum;
83 }
84 #endif /* !HAVE_MIPS32R6 && !HAVE_MIPS64R6 */
85 #endif /* HAVE_INLINE_ASM */
86 
88 {
89 #if HAVE_INLINE_ASM
90 #if !HAVE_MIPS32R6 && !HAVE_MIPS64R6
91  c->dot_productf = ff_dot_productf_mips;
92 #endif
93 #endif
94 }
MIPS assembly defines from sys/asm.h but rewritten for use with C inline assembly (rather than from w...
float(* dot_productf)(const float *a, const float *b, int length)
Return the dot product.
Definition: celp_math.h:37
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:36
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
GLsizei GLsizei * length
Definition: opengl_enc.c:114
#define b
Definition: input.c:41
#define PTR_ADDIU
Definition: asmdefs.h:48
void ff_celp_math_init_mips(CELPMContext *c)