From: mdw Date: Fri, 21 Jul 2000 19:01:33 +0000 (+0000) Subject: Generate the CRC table rather than hardcoding it. X-Git-Tag: 2.0.4~160 X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/mLib/commitdiff_plain/b7580524f33ee21d3ddc49fe36a71e107e87df1b Generate the CRC table rather than hardcoding it. --- diff --git a/Makefile.am b/Makefile.am index 0f8155d..3fe766a 100644 --- a/Makefile.am +++ b/Makefile.am @@ -1,6 +1,6 @@ ## -*-Makefile-*- ## -## $Id: Makefile.am,v 1.21 2000/07/16 18:57:52 mdw Exp $ +## $Id: Makefile.am,v 1.22 2000/07/21 19:01:33 mdw Exp $ ## ## Building the distribution ## @@ -29,6 +29,9 @@ ##----- Revision history ---------------------------------------------------- ## ## $Log: Makefile.am,v $ +## Revision 1.22 2000/07/21 19:01:33 mdw +## Generate the CRC table rather than hardcoding it. +## ## Revision 1.21 2000/07/16 18:57:52 mdw ## New files. Test cases for `bits.h'. ## @@ -79,6 +82,7 @@ AUTOMAKE_OPTIONS = foreign SUBDIRS = man bin_SCRIPTS = mLib-config +bin_PROGRAMS = crc-mktab lib_LTLIBRARIES = libmLib.la libexec_PROGRAMS = bres @@ -102,12 +106,21 @@ libmLib_la_SOURCES = \ alloc.c arena.c exc.c quis.c pquis.c report.c sub.c trace.c \ traceopt.c track.c \ pool.c pool-file.c pool-sub.c \ - darray.c dstr.c dputf.c dspool.c hash.c sym.c crc32.c \ + darray.c dstr.c dputf.c dspool.c hash.c sym.c crc32.c crc32-tab.c \ env.c fdflags.c lock.c \ bres.c conn.c lbuf.c ident.c pkbuf.c sel.c selbuf.c selpk.c sig.c \ tv.c \ base64.c mdwopt.c str.c testrig.c url.c +BUILT_SOURCES = crc32-tab.c + +crc32-tab.c: crc-mktab + ./crc-mktab \ + -p0x04c11db7 -b32 -B8 -r \ + -c -scrc32_table -icrc32.h -tuint32 -ocrc32-tab.c + +crc_mktab_SOURCES = crc-mktab.c mdwopt.c quis.c pquis.c report.c + ## --- Test code --- noinst_PROGRAMS = da-test sym-test bits.t diff --git a/crc-mktab.c b/crc-mktab.c new file mode 100644 index 0000000..887315b --- /dev/null +++ b/crc-mktab.c @@ -0,0 +1,360 @@ +/* -*-c-*- + * + * $Id: crc-mktab.c,v 1.1 2000/07/21 19:01:33 mdw Exp $ + * + * Build CRC tables + * + * (c) 2000 Straylight/Edgeware + */ + +/*----- Licensing notice --------------------------------------------------* + * + * This file is part of the mLib utilities library. + * + * mLib is free software; you can redistribute it and/or modify + * it under the terms of the GNU Library General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or (at your option) any later version. + * + * mLib is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with mLib; if not, write to the Free + * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + * MA 02111-1307, USA. + */ + +/*----- Revision history --------------------------------------------------* + * + * $Log: crc-mktab.c,v $ + * Revision 1.1 2000/07/21 19:01:33 mdw + * Generate the CRC table rather than hardcoding it. + * + */ + +/*----- Header files ------------------------------------------------------*/ + +#include +#include +#include +#include +#include +#include +#include + +#include "mdwopt.h" +#include "quis.h" +#include "report.h" + +/*----- Static variables --------------------------------------------------*/ + +static unsigned long poly = 0; +static const char *guard = 0; +static unsigned bits = 0; +static unsigned chunk = 8; +static const char *file = 0; +static unsigned flags = 0; +static const char *sym = 0; +static const char *type = 0; +static const char *inc = 0; +static FILE *fp; + +enum { + f_bogus = 1, + f_ctab = 2, + f_reverse = 4 +}; + +#define BSCOL 72 + +/*----- Main code ---------------------------------------------------------*/ + +static unsigned long getint(const char *p, unsigned long max, + const char *what) +{ + char *pp; + unsigned long x = strtoul(p, &pp, 0); + if (*pp || (max && x > max)) + die(EXIT_FAILURE, "bad %s `%s'", what, p); + return (x); +} + +static void version(FILE *fp) +{ + pquis(fp, "$, mLib version " VERSION "\n"); +} + +static void usage(FILE *fp) +{ + pquis(fp, "Usage: $ [-cr] [-g guard] [-o file] [-b bits] [-p poly]\n"); +} + +static void help(FILE *fp) +{ + version(fp); + putc('\n', stdout); + usage(fp); + fputs("\n\ +Emits a table containing precomuted values for CRC algorithms. A number\n\ +of options are provided:\n\ +\n\ +-h, --help Show this help text.\n\ +-v, --version Show the program's version number.\n\ +-u, --usage Show a terse usage message.\n\ +\n\ +-c, --c-source Emit a C source file rather than a header.\n\ +-b, --bits=BITS Emit a table for a BITS bits-wide CRC.\n\ +-B, --bit-chunk=BITS Emit a table to process BITS bits at a time.\n\ +-p, --polynomial=POLY Use the POLY as the dividing polynomial.\n\ +-r, --reverse Create a `reversed' CRC table.\n\ +-g, --guard=GUARD Use GUARD as a multiple-inclusion guard constant.\n\ +-s, --symbol=SYM Name the generated table SYM\n\ +-t, --type=TYPE Give the table entries type TYPE in C source.\n\ +-o, --output=FILE Write the output to FILE.\n\ +", stdout); +} + +unsigned long reflect(unsigned long x, unsigned b) +{ + unsigned long y = 0; + unsigned long xm, ym; + unsigned i; + if (!(flags & f_reverse)) + return (x); + xm = 1; + ym = 1 << (b - 1); + for (i = 0; i < b; i++) { + if (x & xm) + y |= ym; + xm <<= 1; + ym >>= 1; + } + return (y); +} + +int main(int argc, char *argv[]) +{ + unsigned n, t, nw; + unsigned max, i; + unsigned long mask; + + ego(argv[0]); + + for (;;) { + static struct option opts[] = { + { "help", 0, 0, 'h' }, + { "version", 0, 0, 'v' }, + { "usage", 0, 0, 'u' }, + + { "output", OPTF_ARGREQ, 0, 'o' }, + { "c-source", 0, 0, 'c' }, + { "symbol", OPTF_ARGREQ, 0, 's' }, + { "type", OPTF_ARGREQ, 0, 't' }, + { "include", OPTF_ARGREQ, 0, 'i' }, + { "guard", OPTF_ARGREQ, 0, 'g' }, + + { "bits", OPTF_ARGREQ, 0, 'b' }, + { "bit-chunk", OPTF_ARGREQ, 0, 'B' }, + { "polynomial", OPTF_ARGREQ, 0, 'p' }, + { "reverse", 0, 0, 'r' }, + + { 0, 0, 0, 0 } + }; + int i = mdwopt(argc, argv, "hvu o:cs:t:i:g: b:B:p:r", opts, 0, 0, 0); + + if (i < 0) + break; + switch (i) { + case 'h': + help(stdout); + exit(0); + case 'v': + version(stdout); + exit(0); + case 'u': + usage(stdout); + exit(0); + + case 'o': + file = optarg; + break; + case 'c': + flags |= f_ctab; + break; + case 's': + sym = optarg; + break; + case 't': + type = optarg; + break; + case 'i': + inc = optarg; + break; + case 'g': + guard = optarg; + break; + + case 'b': + bits = getint(optarg, 32, "CRC width"); + break; + case 'B': + chunk = getint(optarg, 32, "chunk size"); + break; + case 'p': + poly = getint(optarg, 0xffffffff, "CRC poly"); + break; + case 'r': + flags |= f_reverse; + break; + + default: + flags |= f_bogus; + break; + } + } + if ((flags & f_bogus) || optind != argc) { + usage(stderr); + exit(EXIT_FAILURE); + } + + /* --- Sort out the various parameters --- */ + + if (!poly) { + switch (bits) { + case 16: + if (flags & f_reverse) + poly = 0x8408; + else + poly = 0x1021; + break; + case 32: + case 0: + poly = 0x04c11db7; + flags |= f_reverse; + bits = 32; + break; + default: + die(EXIT_FAILURE, "no standard polynomials for %u bits", bits); + break; + } + } + + if (!bits) { + unsigned long x = poly; + while (x > 1) { + x >>= 8; + bits += 8; + } + } + nw = bits/4; + + if ((flags & f_ctab) && !type) + type = bits > 16 ? "unsigned long" : "unsigned short"; + + /* --- Start output --- */ + + if (!file) + fp = stdout; + else { + if (!(flags & f_ctab) && !guard) { + char *p; + const char *q; + if ((p = malloc(strlen(file) + 1)) == 0) + die(EXIT_FAILURE, "not enough memory"); + guard = p; + for (q = file; *q; p++, q++) { + if (isalnum((unsigned char)*q)) + *p = *q; + else + *p = '_'; + } + *p++ = 0; + } + if ((fp = fopen(file, "w")) == 0) + die(EXIT_FAILURE, "couldn't write `%s': %s", file, strerror(errno)); + } + + if (!sym) + sym = (flags & f_ctab) ? "crctab" : "CRC_TAB"; + + /* --- Dump out the first chunk of the file --- */ + + fprintf(fp, "\ +/* -*-c-*-\n\ + *\n\ + * CRC table (poly = %0*lx%s) [generated]\n\ + */\n\ +\n", + nw, poly, flags & f_reverse ? "; reversed" : ""); + + if (flags & f_ctab) { + if (inc) + fprintf(fp, "#include \"%s\"\n\n", inc); + fprintf(fp, "%s %s[] = {\n", type, sym); + } else { + int n; + if (guard) + fprintf(fp, "#ifndef %s\n#define %s\n\n", guard, guard); + n = fprintf(fp, "#define %s {", sym); + while (n < BSCOL) { + fputc('\t', fp); + n = (n + 8) & ~7; + } + fputc('\n', fp); + } + + /* --- Sort out the line width --- */ + + n = 1; + while (2 + n * (nw + 4) < BSCOL) + n <<= 1; + n >>= 1; + t = 0; + while (((1 + n * (nw + 4)) & ~7) + 8 * t < BSCOL) + t++; + + /* --- Start grinding --- */ + + max = 1 << chunk; + mask = 0xffffffff >> (32 - bits); + fputc(' ', fp); + for (i = 0; i < max; i++) { + unsigned long x; + unsigned j; + + x = reflect(i, chunk) << (bits - chunk); + for (j = 0; j < chunk; j++) + x = ((x << 1) ^ (x & (1 << (bits - 1)) ? poly : 0)) & mask; + x = reflect(x, bits); + + fprintf(fp, " 0x%0*lx", nw, x); + if (i == max - 1) { + if (!(flags & f_ctab) && ((2 + n * (nw + 4)) & ~7) + 8 * t < BSCOL) + fputc('\t', fp); + } else + fputc(',', fp); + if (i + 1 == max || (i + 1)%n == 0) { + if (!(flags & f_ctab)) { + for (j = 0; j < t; j++) + fputc('\t', fp); + fputc('\\', fp); + } + fputc('\n', fp); + if (i + 1 != max) + fputc(' ', fp); + } + } + + /* --- Done --- */ + + fputs(flags & f_ctab ? "};\n" : "}\n", fp); + if (!(flags & f_ctab) && guard) + fputs("\n#endif\n", fp); + + return (0); +} + +/*----- That's all, folks -------------------------------------------------*/ diff --git a/crc32.c b/crc32.c index 5f47665..a24c909 100644 --- a/crc32.c +++ b/crc32.c @@ -1,6 +1,6 @@ /* -*-c-*- * - * $Id: crc32.c,v 1.4 1999/06/01 09:47:22 mdw Exp $ + * $Id: crc32.c,v 1.5 2000/07/21 19:01:33 mdw Exp $ * * Calculating cyclic redundancy values (non-cryptographic!) * @@ -30,6 +30,9 @@ /*----- Revision history --------------------------------------------------* * * $Log: crc32.c,v $ + * Revision 1.5 2000/07/21 19:01:33 mdw + * Generate the CRC table rather than hardcoding it. + * * Revision 1.4 1999/06/01 09:47:22 mdw * Make the return type of `crc32' a `uint32' now that we have `bits.h'. * @@ -57,88 +60,6 @@ #include "bits.h" #include "crc32.h" -/*----- CRC table ---------------------------------------------------------*/ - -/* --- Acknowledgements and information --- * - * - * This table was generated using a derivative of the Rocksoft Model CRC - * generator. The parameters given are: - * - * width = 32bits - * poly = 0x04C11DB7 - * init = -1 - * xorout = -1 - * reverse = yes - * check = crc(123456789) = 0xCBF43926 - */ - -uint32 crc32_table[256] = { - 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, - 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, - 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, - 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, - 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, - 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, - 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, - 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, - 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, - 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, - 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, - 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, - 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, - 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, - 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, - 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, - 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, - 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, - 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, - 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, - 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, - 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, - 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, - 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, - 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, - 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, - 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, - 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, - 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, - 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, - 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, - 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, - 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, - 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, - 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, - 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, - 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, - 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, - 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, - 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, - 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, - 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, - 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, - 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, - 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, - 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, - 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, - 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, - 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, - 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, - 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, - 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, - 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, - 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, - 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, - 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, - 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, - 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, - 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, - 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, - 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, - 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, - 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, - 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d, -}; - /*----- Functionc provided ------------------------------------------------*/ /* --- @crc32@ --- *