sys/tools/sound/snd_fxdiv_gen.awk

   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
  30 function floor(x, r)
  31 {
  32         r = int(x);
  33         if (r > x)
  34                 r--;
  35         return (r + 0);
  36 }
  37
  38 function shl(x, y)
  39 {
  40         while (y > 0) {
  41                 x *= 2;
  42                 y--;
  43         }
  44         return (x);
  45 }
  46
  47 function shr(x, y)
  48 {
  49         while (y > 0 && x != 0) {
  50                 x = floor(x / 2);
  51                 y--;
  52         }
  53         return (x);
  54 }
  55
  56 function 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
  73 BEGIN {
  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 }