diff options
Diffstat (limited to 'crc32.c')
| -rw-r--r-- | crc32.c | 83 |
1 files changed, 33 insertions, 50 deletions
@@ -1,5 +1,5 @@ /* crc32.c -- compute the CRC-32 of a data stream - * Copyright (C) 1995-2006, 2010 Mark Adler + * Copyright (C) 1995-2006, 2010, 2011, 2012 Mark Adler * For conditions of distribution and use, see copyright notice in zlib.h * * Thanks to Rodney Brown <rbrown64@csc.com.au> for his contribution of faster @@ -17,6 +17,8 @@ of the crc tables. Therefore, if you #define DYNAMIC_CRC_TABLE, you should first call get_crc_table() to initialize the tables before allowing more than one thread to use crc32(). + + DYNAMIC_CRC_TABLE and MAKECRCH can be #defined to write out crc32.h. */ #ifdef MAKECRCH @@ -30,31 +32,11 @@ #define local static -/* Find a four-byte integer type for crc32_little() and crc32_big(). */ -#ifndef NOBYFOUR -# ifdef STDC /* need ANSI C limits.h to determine sizes */ -# include <limits.h> -# define BYFOUR -# if (UINT_MAX == 0xffffffffUL) - typedef unsigned int u4; -# else -# if (ULONG_MAX == 0xffffffffUL) - typedef unsigned long u4; -# else -# if (USHRT_MAX == 0xffffffffUL) - typedef unsigned short u4; -# else -# undef BYFOUR /* can't find a four-byte integer type! */ -# endif -# endif -# endif -# endif /* STDC */ -#endif /* !NOBYFOUR */ - /* Definitions for doing the crc four data bytes at a time. */ +#if !defined(NOBYFOUR) && defined(Z_U4) +# define BYFOUR +#endif #ifdef BYFOUR -# define REV(w) ((((w)>>24)&0xff)+(((w)>>8)&0xff00)+ \ - (((w)&0xff00)<<8)+(((w)&0xff)<<24)) local unsigned long crc32_little OF((unsigned long, const unsigned char FAR *, unsigned)); local unsigned long crc32_big OF((unsigned long, @@ -68,16 +50,16 @@ local unsigned long gf2_matrix_times OF((unsigned long *mat, unsigned long vec)); local void gf2_matrix_square OF((unsigned long *square, unsigned long *mat)); -local uLong crc32_combine_(uLong crc1, uLong crc2, z_off64_t len2); +local uLong crc32_combine_ OF((uLong crc1, uLong crc2, z_off64_t len2)); #ifdef DYNAMIC_CRC_TABLE local volatile int crc_table_empty = 1; -local unsigned long FAR crc_table[TBLS][256]; +local z_crc_t FAR crc_table[TBLS][256]; local void make_crc_table OF((void)); #ifdef MAKECRCH - local void write_table OF((FILE *, const unsigned long FAR *)); + local void write_table OF((FILE *, const z_crc_t FAR *)); #endif /* MAKECRCH */ /* Generate tables for a byte-wise 32-bit CRC calculation on the polynomial: @@ -107,9 +89,9 @@ local void make_crc_table OF((void)); */ local void make_crc_table() { - unsigned long c; + z_crc_t c; int n, k; - unsigned long poly; /* polynomial exclusive-or pattern */ + z_crc_t poly; /* polynomial exclusive-or pattern */ /* terms of polynomial defining this crc (except x^32): */ static volatile int first = 1; /* flag to limit concurrent making */ static const unsigned char p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26}; @@ -121,13 +103,13 @@ local void make_crc_table() first = 0; /* make exclusive-or pattern from polynomial (0xedb88320UL) */ - poly = 0UL; - for (n = 0; n < sizeof(p)/sizeof(unsigned char); n++) - poly |= 1UL << (31 - p[n]); + poly = 0; + for (n = 0; n < (int)(sizeof(p)/sizeof(unsigned char)); n++) + poly |= (z_crc_t)1 << (31 - p[n]); /* generate a crc for every 8-bit value */ for (n = 0; n < 256; n++) { - c = (unsigned long)n; + c = (z_crc_t)n; for (k = 0; k < 8; k++) c = c & 1 ? poly ^ (c >> 1) : c >> 1; crc_table[0][n] = c; @@ -138,11 +120,11 @@ local void make_crc_table() and then the byte reversal of those as well as the first table */ for (n = 0; n < 256; n++) { c = crc_table[0][n]; - crc_table[4][n] = REV(c); + crc_table[4][n] = ZSWAP32(c); for (k = 1; k < 4; k++) { c = crc_table[0][c & 0xff] ^ (c >> 8); crc_table[k][n] = c; - crc_table[k + 4][n] = REV(c); + crc_table[k + 4][n] = ZSWAP32(c); } } #endif /* BYFOUR */ @@ -164,7 +146,7 @@ local void make_crc_table() if (out == NULL) return; fprintf(out, "/* crc32.h -- tables for rapid CRC calculation\n"); fprintf(out, " * Generated automatically by crc32.c\n */\n\n"); - fprintf(out, "local const unsigned long FAR "); + fprintf(out, "local const z_crc_t FAR "); fprintf(out, "crc_table[TBLS][256] =\n{\n {\n"); write_table(out, crc_table[0]); # ifdef BYFOUR @@ -184,12 +166,13 @@ local void make_crc_table() #ifdef MAKECRCH local void write_table(out, table) FILE *out; - const unsigned long FAR *table; + const z_crc_t FAR *table; { int n; for (n = 0; n < 256; n++) - fprintf(out, "%s0x%08lxUL%s", n % 5 ? "" : " ", table[n], + fprintf(out, "%s0x%08lxUL%s", n % 5 ? "" : " ", + (unsigned long)(table[n]), n == 255 ? "\n" : (n % 5 == 4 ? ",\n" : ", ")); } #endif /* MAKECRCH */ @@ -204,13 +187,13 @@ local void write_table(out, table) /* ========================================================================= * This function can be used by asm versions of crc32() */ -const unsigned long FAR * ZEXPORT get_crc_table() +const z_crc_t FAR * ZEXPORT get_crc_table() { #ifdef DYNAMIC_CRC_TABLE if (crc_table_empty) make_crc_table(); #endif /* DYNAMIC_CRC_TABLE */ - return (const unsigned long FAR *)crc_table; + return (const z_crc_t FAR *)crc_table; } /* ========================================================================= */ @@ -232,7 +215,7 @@ unsigned long ZEXPORT crc32(crc, buf, len) #ifdef BYFOUR if (sizeof(void *) == sizeof(ptrdiff_t)) { - u4 endian; + z_crc_t endian; endian = 1; if (*((unsigned char *)(&endian))) @@ -266,17 +249,17 @@ local unsigned long crc32_little(crc, buf, len) const unsigned char FAR *buf; unsigned len; { - register u4 c; - register const u4 FAR *buf4; + register z_crc_t c; + register const z_crc_t FAR *buf4; - c = (u4)crc; + c = (z_crc_t)crc; c = ~c; while (len && ((ptrdiff_t)buf & 3)) { c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8); len--; } - buf4 = (const u4 FAR *)(const void FAR *)buf; + buf4 = (const z_crc_t FAR *)(const void FAR *)buf; while (len >= 32) { DOLIT32; len -= 32; @@ -306,17 +289,17 @@ local unsigned long crc32_big(crc, buf, len) const unsigned char FAR *buf; unsigned len; { - register u4 c; - register const u4 FAR *buf4; + register z_crc_t c; + register const z_crc_t FAR *buf4; - c = REV((u4)crc); + c = ZSWAP32((z_crc_t)crc); c = ~c; while (len && ((ptrdiff_t)buf & 3)) { c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8); len--; } - buf4 = (const u4 FAR *)(const void FAR *)buf; + buf4 = (const z_crc_t FAR *)(const void FAR *)buf; buf4--; while (len >= 32) { DOBIG32; @@ -333,7 +316,7 @@ local unsigned long crc32_big(crc, buf, len) c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8); } while (--len); c = ~c; - return (unsigned long)(REV(c)); + return (unsigned long)(ZSWAP32(c)); } #endif /* BYFOUR */ |