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Diffstat (limited to 'src/zlib-ng/crc32.c')
| -rw-r--r-- | src/zlib-ng/crc32.c | 202 |
1 files changed, 0 insertions, 202 deletions
diff --git a/src/zlib-ng/crc32.c b/src/zlib-ng/crc32.c deleted file mode 100644 index 4b488e6..0000000 --- a/src/zlib-ng/crc32.c +++ /dev/null @@ -1,202 +0,0 @@ -/* crc32.c -- compute the CRC-32 of a data stream - * Copyright (C) 1995-2006, 2010, 2011, 2012, 2016, 2018 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 - * CRC methods: exclusive-oring 32 bits of data at a time, and pre-computing - * tables for updating the shift register in one step with three exclusive-ors - * instead of four steps with four exclusive-ors. This results in about a - * factor of two increase in speed on a Power PC G4 (PPC7455) using gcc -O3. - */ - -#include "zbuild.h" -#include "zendian.h" -#include <inttypes.h> -#include "deflate.h" -#include "functable.h" -#include "crc32_tbl.h" - -/* ========================================================================= - * This function can be used by asm versions of crc32() - */ -const uint32_t * Z_EXPORT PREFIX(get_crc_table)(void) { - return (const uint32_t *)crc_table; -} - -#ifdef ZLIB_COMPAT -unsigned long Z_EXPORT PREFIX(crc32_z)(unsigned long crc, const unsigned char *buf, size_t len) { - if (buf == NULL) return 0; - - return (unsigned long)functable.crc32((uint32_t)crc, buf, len); -} -#else -uint32_t Z_EXPORT PREFIX(crc32_z)(uint32_t crc, const unsigned char *buf, size_t len) { - if (buf == NULL) return 0; - - return functable.crc32(crc, buf, len); -} -#endif -/* ========================================================================= */ -#define DO1 crc = crc_table[0][((int)crc ^ (*buf++)) & 0xff] ^ (crc >> 8) -#define DO8 DO1; DO1; DO1; DO1; DO1; DO1; DO1; DO1 -#define DO4 DO1; DO1; DO1; DO1 - -/* ========================================================================= */ -Z_INTERNAL uint32_t crc32_generic(uint32_t crc, const unsigned char *buf, uint64_t len) { - crc = crc ^ 0xffffffff; - -#ifdef UNROLL_MORE - while (len >= 8) { - DO8; - len -= 8; - } -#else - while (len >= 4) { - DO4; - len -= 4; - } -#endif - - if (len) do { - DO1; - } while (--len); - return crc ^ 0xffffffff; -} - -#ifdef ZLIB_COMPAT -unsigned long Z_EXPORT PREFIX(crc32)(unsigned long crc, const unsigned char *buf, unsigned int len) { - return (unsigned long)PREFIX(crc32_z)((uint32_t)crc, buf, len); -} -#else -uint32_t Z_EXPORT PREFIX(crc32)(uint32_t crc, const unsigned char *buf, uint32_t len) { - return PREFIX(crc32_z)(crc, buf, len); -} -#endif - -/* - This BYFOUR code accesses the passed unsigned char * buffer with a 32-bit - integer pointer type. This violates the strict aliasing rule, where a - compiler can assume, for optimization purposes, that two pointers to - fundamentally different types won't ever point to the same memory. This can - manifest as a problem only if one of the pointers is written to. This code - only reads from those pointers. So long as this code remains isolated in - this compilation unit, there won't be a problem. For this reason, this code - should not be copied and pasted into a compilation unit in which other code - writes to the buffer that is passed to these routines. - */ - -/* ========================================================================= */ -#if BYTE_ORDER == LITTLE_ENDIAN -#define DOLIT4 c ^= *buf4++; \ - c = crc_table[3][c & 0xff] ^ crc_table[2][(c >> 8) & 0xff] ^ \ - crc_table[1][(c >> 16) & 0xff] ^ crc_table[0][c >> 24] -#define DOLIT32 DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4 - -/* ========================================================================= */ -Z_INTERNAL uint32_t crc32_little(uint32_t crc, const unsigned char *buf, uint64_t len) { - Z_REGISTER uint32_t c; - Z_REGISTER const uint32_t *buf4; - - c = crc; - c = ~c; - while (len && ((ptrdiff_t)buf & 3)) { - c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8); - len--; - } - - buf4 = (const uint32_t *)(const void *)buf; - -#ifdef UNROLL_MORE - while (len >= 32) { - DOLIT32; - len -= 32; - } -#endif - - while (len >= 4) { - DOLIT4; - len -= 4; - } - buf = (const unsigned char *)buf4; - - if (len) do { - c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8); - } while (--len); - c = ~c; - return c; -} -#endif /* BYTE_ORDER == LITTLE_ENDIAN */ - -/* ========================================================================= */ -#if BYTE_ORDER == BIG_ENDIAN -#define DOBIG4 c ^= *buf4++; \ - c = crc_table[4][c & 0xff] ^ crc_table[5][(c >> 8) & 0xff] ^ \ - crc_table[6][(c >> 16) & 0xff] ^ crc_table[7][c >> 24] -#define DOBIG32 DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4 - -/* ========================================================================= */ -Z_INTERNAL uint32_t crc32_big(uint32_t crc, const unsigned char *buf, uint64_t len) { - Z_REGISTER uint32_t c; - Z_REGISTER const uint32_t *buf4; - - c = ZSWAP32(crc); - c = ~c; - while (len && ((ptrdiff_t)buf & 3)) { - c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8); - len--; - } - - buf4 = (const uint32_t *)(const void *)buf; - -#ifdef UNROLL_MORE - while (len >= 32) { - DOBIG32; - len -= 32; - } -#endif - - while (len >= 4) { - DOBIG4; - len -= 4; - } - buf = (const unsigned char *)buf4; - - if (len) do { - c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8); - } while (--len); - c = ~c; - return ZSWAP32(c); -} -#endif /* BYTE_ORDER == BIG_ENDIAN */ - -#ifdef X86_PCLMULQDQ_CRC -#include "arch/x86/x86.h" -#include "arch/x86/crc_folding.h" - -Z_INTERNAL void crc_finalize(deflate_state *const s) { - if (x86_cpu_has_pclmulqdq) - s->strm->adler = crc_fold_512to32(s); -} -#endif - -Z_INTERNAL void crc_reset(deflate_state *const s) { -#ifdef X86_PCLMULQDQ_CRC - x86_check_features(); - if (x86_cpu_has_pclmulqdq) { - crc_fold_init(s); - return; - } -#endif - s->strm->adler = PREFIX(crc32)(0L, NULL, 0); -} - -Z_INTERNAL void copy_with_crc(PREFIX3(stream) *strm, unsigned char *dst, unsigned long size) { -#ifdef X86_PCLMULQDQ_CRC - if (x86_cpu_has_pclmulqdq) { - crc_fold_copy(strm->state, dst, strm->next_in, size); - return; - } -#endif - memcpy(dst, strm->next_in, size); - strm->adler = PREFIX(crc32)(strm->adler, dst, size); -} |