1#!/usr/bin/awk -f 2# 3# SPDX-License-Identifier: BSD-2-Clause 4# 5# Copyright (c) 2008-2009 Ariff Abdullah <ariff@FreeBSD.org> 6# All rights reserved. 7# 8# Redistribution and use in source and binary forms, with or without 9# modification, are permitted provided that the following conditions 10# are met: 11# 1. Redistributions of source code must retain the above copyright 12# notice, this list of conditions and the following disclaimer. 13# 2. Redistributions in binary form must reproduce the above copyright 14# notice, this list of conditions and the following disclaimer in the 15# documentation and/or other materials provided with the distribution. 16# 17# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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# $FreeBSD$ 30# 31 32function floor(x, r) 33{ 34 r = int(x); 35 if (r > x) 36 r--; 37 return (r + 0); 38} 39 40function shl(x, y) 41{ 42 while (y > 0) { 43 x *= 2; 44 y--; 45 } 46 return (x); 47} 48 49function shr(x, y) 50{ 51 while (y > 0 && x != 0) { 52 x = floor(x / 2); 53 y--; 54 } 55 return (x); 56} 57 58function calcdiv(r, x, y, z) 59{ 60 y = floor(FXONE / x); 61 z = FXSHIFT; 62 63 while (shr((y * x), z) < 1) 64 y++; 65 66 while ((y % 2) == 0 && z > 0) { 67 y = floor(y / 2); 68 z--; 69 } 70 71 r["mul"] = y; 72 r["shift"] = z; 73} 74 75BEGIN { 76 FXSHIFT = 16; 77 FXONE = shl(1, FXSHIFT); 78 79 SND_CHN_MAX = 127; 80 81 PCM_8_BPS = 1; 82 PCM_16_BPS = 2; 83 PCM_24_BPS = 3; 84 PCM_32_BPS = 4; 85 86 SND_MAX_ALIGN = SND_CHN_MAX * PCM_32_BPS; 87 88 for (i = 1; i <= SND_CHN_MAX; i++) { 89 aligns[PCM_8_BPS * i] = 1; 90 aligns[PCM_16_BPS * i] = 1; 91 aligns[PCM_24_BPS * i] = 1; 92 aligns[PCM_32_BPS * i] = 1; 93 } 94 95 printf("#ifndef _SND_FXDIV_GEN_H_\n"); 96 printf("#define _SND_FXDIV_GEN_H_\n\n"); 97 98 printf("/*\n"); 99 printf(" * Generated using snd_fxdiv_gen.awk, heaven, wind and awesome.\n"); 100 printf(" *\n"); 101 printf(" * DO NOT EDIT!\n"); 102 printf(" */\n\n"); 103 printf("#ifdef SND_USE_FXDIV\n\n"); 104 105 printf("/*\n"); 106 printf(" * Fast unsigned 32bit integer division and rounding, accurate for\n"); 107 printf(" * x = 1 - %d. This table should be enough to handle possible\n", FXONE); 108 printf(" * division for 1 - 508 (more can be generated though..).\n"); 109 printf(" *\n"); 110 printf(" * 508 = SND_CHN_MAX * PCM_32_BPS, which is why....\n"); 111 printf(" */\n\n"); 112 113 printf("extern const uint32_t snd_fxdiv_table[%d][2];\n\n", SND_MAX_ALIGN + 1); 114 115 printf("#ifdef SND_DECLARE_FXDIV\n"); 116 printf("const uint32_t snd_fxdiv_table[%d][2] = {\n", SND_MAX_ALIGN + 1); 117 118 for (i = 1; i <= SND_MAX_ALIGN; i++) { 119 if (aligns[i] != 1) 120 continue; 121 calcdiv(r, i); 122 printf("\t[0x%02x] = { 0x%04x, 0x%02x },", \ 123 i, r["mul"], r["shift"]); 124 printf("\t/* x / %-2d = (x * %-5d) >> %-2d */\n", \ 125 i, r["mul"], r["shift"]); 126 } 127 128 printf("};\n#endif\n\n"); 129 130 printf("#define SND_FXDIV_MAX\t\t0x%08x\n", FXONE); 131 printf("#define SND_FXDIV(x, y)\t\t(((uint32_t)(x) *\t\t\t\\\n"); 132 printf("\t\t\t\t snd_fxdiv_table[y][0]) >>\t\t\\\n"); 133 printf("\t\t\t\t snd_fxdiv_table[y][1])\n"); 134 printf("#define SND_FXROUND(x, y)\t(SND_FXDIV(x, y) * (y))\n"); 135 printf("#define SND_FXMOD(x, y)\t\t((x) - SND_FXROUND(x, y))\n\n"); 136 137 printf("#else\t/* !SND_USE_FXDIV */\n\n"); 138 139 printf("#define SND_FXDIV_MAX\t\t0x%08x\n", 131072); 140 printf("#define SND_FXDIV(x, y)\t\t((x) / (y))\n"); 141 printf("#define SND_FXROUND(x, y)\t((x) - ((x) %% (y)))\n"); 142 printf("#define SND_FXMOD(x, y)\t\t((x) %% (y))\n\n"); 143 144 printf("#endif\t/* SND_USE_FXDIV */\n\n"); 145 146 printf("#endif\t/* !_SND_FXDIV_GEN_H_ */\n"); 147} 148