diff options
Diffstat (limited to 'compat/zlib/crc32.c')
| -rw-r--r-- | compat/zlib/crc32.c | 248 |
1 files changed, 86 insertions, 162 deletions
diff --git a/compat/zlib/crc32.c b/compat/zlib/crc32.c index f8357b0..6c38f5c 100644 --- a/compat/zlib/crc32.c +++ b/compat/zlib/crc32.c @@ -103,19 +103,6 @@ # define ARMCRC32 #endif -/* Local functions. */ -local z_crc_t multmodp OF((z_crc_t a, z_crc_t b)); -local z_crc_t x2nmodp OF((z_off64_t n, unsigned k)); - -#if defined(W) && (!defined(ARMCRC32) || defined(DYNAMIC_CRC_TABLE)) - local z_word_t byte_swap OF((z_word_t word)); -#endif - -#if defined(W) && !defined(ARMCRC32) - local z_crc_t crc_word OF((z_word_t data)); - local z_word_t crc_word_big OF((z_word_t data)); -#endif - #if defined(W) && (!defined(ARMCRC32) || defined(DYNAMIC_CRC_TABLE)) /* Swap the bytes in a z_word_t to convert between little and big endian. Any @@ -123,9 +110,7 @@ local z_crc_t x2nmodp OF((z_off64_t n, unsigned k)); instruction, if one is available. This assumes that word_t is either 32 bits or 64 bits. */ -local z_word_t byte_swap(word) - z_word_t word; -{ +local z_word_t byte_swap(z_word_t word) { # if W == 8 return (word & 0xff00000000000000) >> 56 | @@ -146,24 +131,77 @@ local z_word_t byte_swap(word) } #endif +#ifdef DYNAMIC_CRC_TABLE +/* ========================================================================= + * Table of powers of x for combining CRC-32s, filled in by make_crc_table() + * below. + */ + local z_crc_t FAR x2n_table[32]; +#else +/* ========================================================================= + * Tables for byte-wise and braided CRC-32 calculations, and a table of powers + * of x for combining CRC-32s, all made by make_crc_table(). + */ +# include "crc32.h" +#endif + /* CRC polynomial. */ #define POLY 0xedb88320 /* p(x) reflected, with x^32 implied */ -#ifdef DYNAMIC_CRC_TABLE +/* + Return a(x) multiplied by b(x) modulo p(x), where p(x) is the CRC polynomial, + reflected. For speed, this requires that a not be zero. + */ +local z_crc_t multmodp(z_crc_t a, z_crc_t b) { + z_crc_t m, p; + + m = (z_crc_t)1 << 31; + p = 0; + for (;;) { + if (a & m) { + p ^= b; + if ((a & (m - 1)) == 0) + break; + } + m >>= 1; + b = b & 1 ? (b >> 1) ^ POLY : b >> 1; + } + return p; +} +/* + Return x^(n * 2^k) modulo p(x). Requires that x2n_table[] has been + initialized. + */ +local z_crc_t x2nmodp(z_off64_t n, unsigned k) { + z_crc_t p; + + p = (z_crc_t)1 << 31; /* x^0 == 1 */ + while (n) { + if (n & 1) + p = multmodp(x2n_table[k & 31], p); + n >>= 1; + k++; + } + return p; +} + +#ifdef DYNAMIC_CRC_TABLE +/* ========================================================================= + * Build the tables for byte-wise and braided CRC-32 calculations, and a table + * of powers of x for combining CRC-32s. + */ local z_crc_t FAR crc_table[256]; -local z_crc_t FAR x2n_table[32]; -local void make_crc_table OF((void)); #ifdef W local z_word_t FAR crc_big_table[256]; local z_crc_t FAR crc_braid_table[W][256]; local z_word_t FAR crc_braid_big_table[W][256]; - local void braid OF((z_crc_t [][256], z_word_t [][256], int, int)); + local void braid(z_crc_t [][256], z_word_t [][256], int, int); #endif #ifdef MAKECRCH - local void write_table OF((FILE *, const z_crc_t FAR *, int)); - local void write_table32hi OF((FILE *, const z_word_t FAR *, int)); - local void write_table64 OF((FILE *, const z_word_t FAR *, int)); + local void write_table(FILE *, const z_crc_t FAR *, int); + local void write_table32hi(FILE *, const z_word_t FAR *, int); + local void write_table64(FILE *, const z_word_t FAR *, int); #endif /* MAKECRCH */ /* @@ -176,7 +214,6 @@ local void make_crc_table OF((void)); /* Definition of once functionality. */ typedef struct once_s once_t; -local void once OF((once_t *, void (*)(void))); /* Check for the availability of atomics. */ #if defined(__STDC__) && __STDC_VERSION__ >= 201112L && \ @@ -196,10 +233,7 @@ struct once_s { invoke once() at the same time. The state must be a once_t initialized with ONCE_INIT. */ -local void once(state, init) - once_t *state; - void (*init)(void); -{ +local void once(once_t *state, void (*init)(void)) { if (!atomic_load(&state->done)) { if (atomic_flag_test_and_set(&state->begun)) while (!atomic_load(&state->done)) @@ -222,10 +256,7 @@ struct once_s { /* Test and set. Alas, not atomic, but tries to minimize the period of vulnerability. */ -local int test_and_set OF((int volatile *)); -local int test_and_set(flag) - int volatile *flag; -{ +local int test_and_set(int volatile *flag) { int was; was = *flag; @@ -234,10 +265,7 @@ local int test_and_set(flag) } /* Run the provided init() function once. This is not thread-safe. */ -local void once(state, init) - once_t *state; - void (*init)(void); -{ +local void once(once_t *state, void (*init)(void)) { if (!state->done) { if (test_and_set(&state->begun)) while (!state->done) @@ -279,8 +307,7 @@ local once_t made = ONCE_INIT; combinations of CRC register values and incoming bytes. */ -local void make_crc_table() -{ +local void make_crc_table(void) { unsigned i, j, n; z_crc_t p; @@ -447,11 +474,7 @@ local void make_crc_table() Write the 32-bit values in table[0..k-1] to out, five per line in hexadecimal separated by commas. */ -local void write_table(out, table, k) - FILE *out; - const z_crc_t FAR *table; - int k; -{ +local void write_table(FILE *out, const z_crc_t FAR *table, int k) { int n; for (n = 0; n < k; n++) @@ -464,11 +487,7 @@ local void write_table(out, table, k) Write the high 32-bits of each value in table[0..k-1] to out, five per line in hexadecimal separated by commas. */ -local void write_table32hi(out, table, k) -FILE *out; -const z_word_t FAR *table; -int k; -{ +local void write_table32hi(FILE *out, const z_word_t FAR *table, int k) { int n; for (n = 0; n < k; n++) @@ -484,11 +503,7 @@ int k; bits. If not, then the type cast and format string can be adjusted accordingly. */ -local void write_table64(out, table, k) - FILE *out; - const z_word_t FAR *table; - int k; -{ +local void write_table64(FILE *out, const z_word_t FAR *table, int k) { int n; for (n = 0; n < k; n++) @@ -498,8 +513,7 @@ local void write_table64(out, table, k) } /* Actually do the deed. */ -int main() -{ +int main(void) { make_crc_table(); return 0; } @@ -511,12 +525,7 @@ int main() Generate the little and big-endian braid tables for the given n and z_word_t size w. Each array must have room for w blocks of 256 elements. */ -local void braid(ltl, big, n, w) - z_crc_t ltl[][256]; - z_word_t big[][256]; - int n; - int w; -{ +local void braid(z_crc_t ltl[][256], z_word_t big[][256], int n, int w) { int k; z_crc_t i, p, q; for (k = 0; k < w; k++) { @@ -531,69 +540,13 @@ local void braid(ltl, big, n, w) } #endif -#else /* !DYNAMIC_CRC_TABLE */ -/* ======================================================================== - * Tables for byte-wise and braided CRC-32 calculations, and a table of powers - * of x for combining CRC-32s, all made by make_crc_table(). - */ -#include "crc32.h" #endif /* DYNAMIC_CRC_TABLE */ -/* ======================================================================== - * Routines used for CRC calculation. Some are also required for the table - * generation above. - */ - -/* - Return a(x) multiplied by b(x) modulo p(x), where p(x) is the CRC polynomial, - reflected. For speed, this requires that a not be zero. - */ -local z_crc_t multmodp(a, b) - z_crc_t a; - z_crc_t b; -{ - z_crc_t m, p; - - m = (z_crc_t)1 << 31; - p = 0; - for (;;) { - if (a & m) { - p ^= b; - if ((a & (m - 1)) == 0) - break; - } - m >>= 1; - b = b & 1 ? (b >> 1) ^ POLY : b >> 1; - } - return p; -} - -/* - Return x^(n * 2^k) modulo p(x). Requires that x2n_table[] has been - initialized. - */ -local z_crc_t x2nmodp(n, k) - z_off64_t n; - unsigned k; -{ - z_crc_t p; - - p = (z_crc_t)1 << 31; /* x^0 == 1 */ - while (n) { - if (n & 1) - p = multmodp(x2n_table[k & 31], p); - n >>= 1; - k++; - } - return p; -} - /* ========================================================================= * This function can be used by asm versions of crc32(), and to force the * generation of the CRC tables in a threaded application. */ -const z_crc_t FAR * ZEXPORT get_crc_table() -{ +const z_crc_t FAR * ZEXPORT get_crc_table(void) { #ifdef DYNAMIC_CRC_TABLE once(&made, make_crc_table); #endif /* DYNAMIC_CRC_TABLE */ @@ -619,11 +572,8 @@ const z_crc_t FAR * ZEXPORT get_crc_table() #define Z_BATCH_ZEROS 0xa10d3d0c /* computed from Z_BATCH = 3990 */ #define Z_BATCH_MIN 800 /* fewest words in a final batch */ -unsigned long ZEXPORT crc32_z(crc, buf, len) - unsigned long crc; - const unsigned char FAR *buf; - z_size_t len; -{ +unsigned long ZEXPORT crc32_z(unsigned long crc, const unsigned char FAR *buf, + z_size_t len) { z_crc_t val; z_word_t crc1, crc2; const z_word_t *word; @@ -723,18 +673,14 @@ unsigned long ZEXPORT crc32_z(crc, buf, len) least-significant byte of the word as the first byte of data, without any pre or post conditioning. This is used to combine the CRCs of each braid. */ -local z_crc_t crc_word(data) - z_word_t data; -{ +local z_crc_t crc_word(z_word_t data) { int k; for (k = 0; k < W; k++) data = (data >> 8) ^ crc_table[data & 0xff]; return (z_crc_t)data; } -local z_word_t crc_word_big(data) - z_word_t data; -{ +local z_word_t crc_word_big(z_word_t data) { int k; for (k = 0; k < W; k++) data = (data << 8) ^ @@ -745,11 +691,8 @@ local z_word_t crc_word_big(data) #endif /* ========================================================================= */ -unsigned long ZEXPORT crc32_z(crc, buf, len) - unsigned long crc; - const unsigned char FAR *buf; - z_size_t len; -{ +unsigned long ZEXPORT crc32_z(unsigned long crc, const unsigned char FAR *buf, + z_size_t len) { /* Return initial CRC, if requested. */ if (buf == Z_NULL) return 0; @@ -781,8 +724,8 @@ unsigned long ZEXPORT crc32_z(crc, buf, len) words = (z_word_t const *)buf; /* Do endian check at execution time instead of compile time, since ARM - processors can change the endianess at execution time. If the - compiler knows what the endianess will be, it can optimize out the + processors can change the endianness at execution time. If the + compiler knows what the endianness will be, it can optimize out the check and the unused branch. */ endian = 1; if (*(unsigned char *)&endian) { @@ -1069,20 +1012,13 @@ unsigned long ZEXPORT crc32_z(crc, buf, len) #endif /* ========================================================================= */ -unsigned long ZEXPORT crc32(crc, buf, len) - unsigned long crc; - const unsigned char FAR *buf; - uInt len; -{ +unsigned long ZEXPORT crc32(unsigned long crc, const unsigned char FAR *buf, + uInt len) { return crc32_z(crc, buf, len); } /* ========================================================================= */ -uLong ZEXPORT crc32_combine64(crc1, crc2, len2) - uLong crc1; - uLong crc2; - z_off64_t len2; -{ +uLong ZEXPORT crc32_combine64(uLong crc1, uLong crc2, z_off64_t len2) { #ifdef DYNAMIC_CRC_TABLE once(&made, make_crc_table); #endif /* DYNAMIC_CRC_TABLE */ @@ -1090,18 +1026,12 @@ uLong ZEXPORT crc32_combine64(crc1, crc2, len2) } /* ========================================================================= */ -uLong ZEXPORT crc32_combine(crc1, crc2, len2) - uLong crc1; - uLong crc2; - z_off_t len2; -{ +uLong ZEXPORT crc32_combine(uLong crc1, uLong crc2, z_off_t len2) { return crc32_combine64(crc1, crc2, (z_off64_t)len2); } /* ========================================================================= */ -uLong ZEXPORT crc32_combine_gen64(len2) - z_off64_t len2; -{ +uLong ZEXPORT crc32_combine_gen64(z_off64_t len2) { #ifdef DYNAMIC_CRC_TABLE once(&made, make_crc_table); #endif /* DYNAMIC_CRC_TABLE */ @@ -1109,17 +1039,11 @@ uLong ZEXPORT crc32_combine_gen64(len2) } /* ========================================================================= */ -uLong ZEXPORT crc32_combine_gen(len2) - z_off_t len2; -{ +uLong ZEXPORT crc32_combine_gen(z_off_t len2) { return crc32_combine_gen64((z_off64_t)len2); } /* ========================================================================= */ -uLong ZEXPORT crc32_combine_op(crc1, crc2, op) - uLong crc1; - uLong crc2; - uLong op; -{ +uLong ZEXPORT crc32_combine_op(uLong crc1, uLong crc2, uLong op) { return multmodp(op, crc1) ^ (crc2 & 0xffffffff); } |