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# $FreeBSD$ 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 = 127; 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 - 508 (more can be generated though..).\n"); 107 printf(" *\n"); 108 printf(" * 508 = SND_CHN_MAX * PCM_32_BPS, which is why....\n"); 109 printf(" */\n\n"); 110 111 printf("extern const uint32_t snd_fxdiv_table[%d][2];\n\n", SND_MAX_ALIGN + 1); 112 113 printf("#ifdef SND_DECLARE_FXDIV\n"); 114 printf("const uint32_t snd_fxdiv_table[%d][2] = {\n", SND_MAX_ALIGN + 1); 115 116 for (i = 1; i <= SND_MAX_ALIGN; i++) { 117 if (aligns[i] != 1) 118 continue; 119 calcdiv(r, i); 120 printf("\t[0x%02x] = { 0x%04x, 0x%02x },", \ 121 i, r["mul"], r["shift"]); 122 printf("\t/* x / %-2d = (x * %-5d) >> %-2d */\n", \ 123 i, r["mul"], r["shift"]); 124 } 125 126 printf("};\n#endif\n\n"); 127 128 printf("#define SND_FXDIV_MAX\t\t0x%08x\n", FXONE); 129 printf("#define SND_FXDIV(x, y)\t\t(((uint32_t)(x) *\t\t\t\\\n"); 130 printf("\t\t\t\t snd_fxdiv_table[y][0]) >>\t\t\\\n"); 131 printf("\t\t\t\t snd_fxdiv_table[y][1])\n"); 132 printf("#define SND_FXROUND(x, y)\t(SND_FXDIV(x, y) * (y))\n"); 133 printf("#define SND_FXMOD(x, y)\t\t((x) - SND_FXROUND(x, y))\n\n"); 134 135 printf("#else\t/* !SND_USE_FXDIV */\n\n"); 136 137 printf("#define SND_FXDIV_MAX\t\t0x%08x\n", 131072); 138 printf("#define SND_FXDIV(x, y)\t\t((x) / (y))\n"); 139 printf("#define SND_FXROUND(x, y)\t((x) - ((x) %% (y)))\n"); 140 printf("#define SND_FXMOD(x, y)\t\t((x) %% (y))\n\n"); 141 142 printf("#endif\t/* SND_USE_FXDIV */\n\n"); 143 144 printf("#endif\t/* !_SND_FXDIV_GEN_H_ */\n"); 145} 146