xref: /dragonfly/sys/tools/sound/snd_fxdiv_gen.awk (revision 2a1ad637466621af45d5a17185b33f3dcaaa1b1c) 
1#!/usr/bin/awk -f
2#
3# Copyright (c) 2008-2009 Ariff Abdullah <ariff@FreeBSD.org>
4# All rights reserved.
5#
6# Redistribution and use in source and binary forms, with or without
7# modification, are permitted provided that the following conditions
8# are met:
9# 1. Redistributions of source code must retain the above copyright
10#    notice, this list of conditions and the following disclaimer.
11# 2. Redistributions in binary form must reproduce the above copyright
12#    notice, this list of conditions and the following disclaimer in the
13#    documentation and/or other materials provided with the distribution.
14#
15# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25# SUCH DAMAGE.
26#
27# $FreeBSD: head/sys/tools/sound/snd_fxdiv_gen.awk 193889 2009-06-10 06:49:45Z ariff $
28#
29
30function floor(x, r)
31{
32          r = int(x);
33          if (r > x)
34                    r--;
35          return (r + 0);
36}
37
38function shl(x, y)
39{
40          while (y > 0) {
41                    x *= 2;
42                    y--;
43          }
44          return (x);
45}
46
47function shr(x, y)
48{
49          while (y > 0 && x != 0) {
50                    x = floor(x / 2);
51                    y--;
52          }
53          return (x);
54}
55
56function calcdiv(r, x, y, z)
57{
58          y = floor(FXONE / x);
59          z = FXSHIFT;
60
61          while (shr((y * x), z) < 1)
62                    y++;
63
64          while ((y % 2) == 0 && z > 0) {
65                    y = floor(y / 2);
66                    z--;
67          }
68
69          r["mul"] = y;
70          r["shift"] = z;
71}
72
73BEGIN {
74          FXSHIFT = 16;
75          FXONE   = shl(1, FXSHIFT);
76
77          SND_CHN_MAX = 18;
78
79          PCM_8_BPS  = 1;
80          PCM_16_BPS = 2;
81          PCM_24_BPS = 3;
82          PCM_32_BPS = 4;
83
84          SND_MAX_ALIGN = SND_CHN_MAX * PCM_32_BPS;
85
86          for (i = 1; i <= SND_CHN_MAX; i++) {
87                    aligns[PCM_8_BPS * i]  = 1;
88                    aligns[PCM_16_BPS * i] = 1;
89                    aligns[PCM_24_BPS * i] = 1;
90                    aligns[PCM_32_BPS * i] = 1;
91          }
92
93          printf("#ifndef _SND_FXDIV_GEN_H_\n");
94          printf("#define _SND_FXDIV_GEN_H_\n\n");
95
96          printf("/*\n");
97          printf(" * Generated using snd_fxdiv_gen.awk, heaven, wind and awesome.\n");
98          printf(" *\n");
99          printf(" * DO NOT EDIT!\n");
100          printf(" */\n\n");
101          printf("#ifdef SND_USE_FXDIV\n\n");
102
103          printf("/*\n");
104          printf(" * Fast unsigned 32bit integer division and rounding, accurate for\n");
105          printf(" * x = 1 - %d. This table should be enough to handle possible\n", FXONE);
106          printf(" * division for 1 - 72 (more can be generated though..).\n");
107          printf(" *\n");
108          printf(" * 72 = SND_CHN_MAX * PCM_32_BPS, which is why....\n");
109          printf(" */\n\n");
110
111          printf("static const uint32_t snd_fxdiv_table[][2] = {\n");
112
113          for (i = 1; i <= SND_MAX_ALIGN; i++) {
114                    if (aligns[i] != 1)
115                              continue;
116                    calcdiv(r, i);
117                    printf("\t[0x%02x] = { 0x%04x, 0x%02x },",                  \
118                        i, r["mul"], r["shift"]);
119                    printf("\t/* x / %-2d = (x * %-5d) >> %-2d */\n", \
120                        i, r["mul"], r["shift"]);
121          }
122
123          printf("};\n\n");
124
125          printf("#define SND_FXDIV_MAX\t\t0x%08x\n", FXONE);
126          printf("#define SND_FXDIV(x, y)\t\t(((uint32_t)(x) *\t\t\t\\\n");
127          printf("\t\t\t\t    snd_fxdiv_table[y][0]) >>\t\t\\\n");
128          printf("\t\t\t\t    snd_fxdiv_table[y][1])\n");
129          printf("#define SND_FXROUND(x, y)\t(SND_FXDIV(x, y) * (y))\n");
130          printf("#define SND_FXMOD(x, y)\t\t((x) - SND_FXROUND(x, y))\n\n");
131
132          printf("#else\t/* !SND_USE_FXDIV */\n\n");
133
134          printf("#define SND_FXDIV_MAX\t\t0x%08x\n", 131072);
135          printf("#define SND_FXDIV(x, y)\t\t((x) / (y))\n");
136          printf("#define SND_FXROUND(x, y)\t((x) - ((x) %% (y)))\n");
137          printf("#define SND_FXMOD(x, y)\t\t((x) %% (y))\n\n");
138
139          printf("#endif\t/* SND_USE_FXDIV */\n\n");
140
141          printf("#endif\t/* !_SND_FXDIV_GEN_H_ */\n");
142}
143