FFmpeg
lpc.c
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1 /*
2  * SIMD-optimized LPC functions
3  * Copyright (c) 2007 Loren Merritt
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/attributes.h"
23 #include "libavutil/cpu.h"
24 #include "libavutil/mem.h"
25 #include "libavutil/x86/asm.h"
26 #include "libavutil/x86/cpu.h"
27 #include "libavcodec/lpc.h"
28 
29 DECLARE_ASM_CONST(16, double, pd_1)[2] = { 1.0, 1.0 };
30 DECLARE_ASM_CONST(16, double, pd_2)[2] = { 2.0, 2.0 };
31 
32 #if HAVE_SSE2_INLINE
33 
34 static void lpc_apply_welch_window_sse2(const int32_t *data, int len,
35  double *w_data)
36 {
37  double c = 2.0 / (len-1.0);
38  int n2 = len>>1;
39  x86_reg i = -n2*sizeof(int32_t);
40  x86_reg j = n2*sizeof(int32_t);
41  __asm__ volatile(
42  "movsd %4, %%xmm7 \n\t"
43  "movapd "MANGLE(pd_1)", %%xmm6 \n\t"
44  "movapd "MANGLE(pd_2)", %%xmm5 \n\t"
45  "movlhps %%xmm7, %%xmm7 \n\t"
46  "subpd %%xmm5, %%xmm7 \n\t"
47  "addsd %%xmm6, %%xmm7 \n\t"
48  "test $1, %5 \n\t"
49  "jz 2f \n\t"
50 #define WELCH(MOVPD, offset)\
51  "1: \n\t"\
52  "movapd %%xmm7, %%xmm1 \n\t"\
53  "mulpd %%xmm1, %%xmm1 \n\t"\
54  "movapd %%xmm6, %%xmm0 \n\t"\
55  "subpd %%xmm1, %%xmm0 \n\t"\
56  "pshufd $0x4e, %%xmm0, %%xmm1 \n\t"\
57  "cvtpi2pd (%3,%0), %%xmm2 \n\t"\
58  "cvtpi2pd "#offset"*4(%3,%1), %%xmm3 \n\t"\
59  "mulpd %%xmm0, %%xmm2 \n\t"\
60  "mulpd %%xmm1, %%xmm3 \n\t"\
61  "movapd %%xmm2, (%2,%0,2) \n\t"\
62  MOVPD" %%xmm3, "#offset"*8(%2,%1,2) \n\t"\
63  "subpd %%xmm5, %%xmm7 \n\t"\
64  "sub $8, %1 \n\t"\
65  "add $8, %0 \n\t"\
66  "jl 1b \n\t"\
67 
68  WELCH("movupd", -1)
69  "jmp 3f \n\t"
70  "2: \n\t"
71  WELCH("movapd", -2)
72  "3: \n\t"
73  :"+&r"(i), "+&r"(j)
74  :"r"(w_data+n2), "r"(data+n2), "m"(c), "r"(len)
76  XMM_CLOBBERS_ONLY("%xmm0", "%xmm1", "%xmm2", "%xmm3",
77  "%xmm5", "%xmm6", "%xmm7")
78  );
79 #undef WELCH
80 }
81 
82 static void lpc_compute_autocorr_sse2(const double *data, int len, int lag,
83  double *autoc)
84 {
85  int j;
86 
87  if((x86_reg)data & 15)
88  data++;
89 
90  for(j=0; j<lag; j+=2){
91  x86_reg i = -len*sizeof(double);
92  if(j == lag-2) {
93  __asm__ volatile(
94  "movsd "MANGLE(pd_1)", %%xmm0 \n\t"
95  "movsd "MANGLE(pd_1)", %%xmm1 \n\t"
96  "movsd "MANGLE(pd_1)", %%xmm2 \n\t"
97  "1: \n\t"
98  "movapd (%2,%0), %%xmm3 \n\t"
99  "movupd -8(%3,%0), %%xmm4 \n\t"
100  "movapd (%3,%0), %%xmm5 \n\t"
101  "mulpd %%xmm3, %%xmm4 \n\t"
102  "mulpd %%xmm3, %%xmm5 \n\t"
103  "mulpd -16(%3,%0), %%xmm3 \n\t"
104  "addpd %%xmm4, %%xmm1 \n\t"
105  "addpd %%xmm5, %%xmm0 \n\t"
106  "addpd %%xmm3, %%xmm2 \n\t"
107  "add $16, %0 \n\t"
108  "jl 1b \n\t"
109  "movhlps %%xmm0, %%xmm3 \n\t"
110  "movhlps %%xmm1, %%xmm4 \n\t"
111  "movhlps %%xmm2, %%xmm5 \n\t"
112  "addsd %%xmm3, %%xmm0 \n\t"
113  "addsd %%xmm4, %%xmm1 \n\t"
114  "addsd %%xmm5, %%xmm2 \n\t"
115  "movsd %%xmm0, (%1) \n\t"
116  "movsd %%xmm1, 8(%1) \n\t"
117  "movsd %%xmm2, 16(%1) \n\t"
118  :"+&r"(i)
119  :"r"(autoc+j), "r"(data+len), "r"(data+len-j)
121  :"memory"
122  );
123  } else {
124  __asm__ volatile(
125  "movsd "MANGLE(pd_1)", %%xmm0 \n\t"
126  "movsd "MANGLE(pd_1)", %%xmm1 \n\t"
127  "1: \n\t"
128  "movapd (%3,%0), %%xmm3 \n\t"
129  "movupd -8(%4,%0), %%xmm4 \n\t"
130  "mulpd %%xmm3, %%xmm4 \n\t"
131  "mulpd (%4,%0), %%xmm3 \n\t"
132  "addpd %%xmm4, %%xmm1 \n\t"
133  "addpd %%xmm3, %%xmm0 \n\t"
134  "add $16, %0 \n\t"
135  "jl 1b \n\t"
136  "movhlps %%xmm0, %%xmm3 \n\t"
137  "movhlps %%xmm1, %%xmm4 \n\t"
138  "addsd %%xmm3, %%xmm0 \n\t"
139  "addsd %%xmm4, %%xmm1 \n\t"
140  "movsd %%xmm0, %1 \n\t"
141  "movsd %%xmm1, %2 \n\t"
142  :"+&r"(i), "=m"(autoc[j]), "=m"(autoc[j+1])
143  :"r"(data+len), "r"(data+len-j)
145  );
146  }
147  }
148 }
149 
150 #endif /* HAVE_SSE2_INLINE */
151 
153 {
154 #if HAVE_SSE2_INLINE
155  int cpu_flags = av_get_cpu_flags();
156 
157  if (INLINE_SSE2(cpu_flags) || INLINE_SSE2_SLOW(cpu_flags)) {
158  c->lpc_apply_welch_window = lpc_apply_welch_window_sse2;
159  c->lpc_compute_autocorr = lpc_compute_autocorr_sse2;
160  }
161 #endif /* HAVE_SSE2_INLINE */
162 }
#define MANGLE(a)
Definition: asm.h:127
DECLARE_ASM_CONST(16, double, pd_1)[2]
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
Definition: lpc.h:52
Memory handling functions.
#define INLINE_SSE2(flags)
Definition: cpu.h:89
static atomic_int cpu_flags
Definition: cpu.c:50
Macro definitions for various function/variable attributes.
#define INLINE_SSE2_SLOW(flags)
Definition: cpu.h:91
av_cold void ff_lpc_init_x86(LPCContext *c)
Definition: lpc.c:152
#define av_cold
Definition: attributes.h:82
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
#define NAMED_CONSTRAINTS_ARRAY_ADD(...)
Definition: asm.h:150
void(* lpc_apply_welch_window)(const int32_t *data, int len, double *w_data)
Apply a Welch window to an array of input samples.
Definition: lpc.h:67
int32_t
void(* lpc_compute_autocorr)(const double *data, int len, int lag, double *autoc)
Perform autocorrelation on input samples with delay of 0 to lag.
Definition: lpc.h:82
int av_get_cpu_flags(void)
Return the flags which specify extensions supported by the CPU.
Definition: cpu.c:93
#define XMM_CLOBBERS_ONLY(...)
Definition: asm.h:99
int x86_reg
Definition: asm.h:72
int len