Reorganize our CRC source files again.

Now that we use CRC-32C in WAL and the control file, the "traditional" and
"legacy" CRC-32 variants are not used in any frontend programs anymore.
Move the code for those back from src/common to src/backend/utils/hash.

Also move the slicing-by-8 implementation (back) to src/port. This is in
preparation for next patch that will add another implementation that uses
Intel SSE 4.2 instructions to calculate CRC-32C, where available.

1 files changed, 0 insertions, 142 deletions

diff --git a/src/include/common/pg_crc.h b/src/include/common/pg_crc.h
deleted file mode 100644
index f496659baf..0000000000
--- a/src/include/common/pg_crc.h
+++ /dev/null
@@ -1,142 +0,0 @@
-/*
- * pg_crc.h
- *
- * PostgreSQL CRC support
- *
- * See Ross Williams' excellent introduction
- * A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from
- * http://www.ross.net/crc/ or several other net sites.
- *
- * We have three slightly different variants of a 32-bit CRC calculation:
- * CRC-32C (Castagnoli polynomial), CRC-32 (Ethernet polynomial), and a legacy
- * CRC-32 version that uses the lookup table in a funny way. They all consist
- * of four macros:
- *
- * INIT_<variant>(crc)
- *		Initialize a CRC accumulator
- *
- * COMP_<variant>(crc, data, len)
- *		Accumulate some (more) bytes into a CRC
- *
- * FIN_<variant>(crc)
- *		Finish a CRC calculation
- *
- * EQ_<variant>(c1, c2)
- *		Check for equality of two CRCs.
- *
- * Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * src/include/common/pg_crc.h
- */
-#ifndef PG_CRC_H
-#define PG_CRC_H
-
-/* ugly hack to let this be used in frontend and backend code on Cygwin */
-#ifdef FRONTEND
-#define CRCDLLIMPORT
-#else
-#define CRCDLLIMPORT PGDLLIMPORT
-#endif
-
-typedef uint32 pg_crc32;
-
-#ifdef HAVE__BUILTIN_BSWAP32
-#define BSWAP32(x) __builtin_bswap32(x)
-#else
-#define BSWAP32(x) (((x << 24) & 0xff000000) | \
-					((x << 8) & 0x00ff0000) | \
-					((x >> 8) & 0x0000ff00) | \
-					((x >> 24) & 0x000000ff))
-#endif
-
-/*
- * CRC calculation using the CRC-32C (Castagnoli) polynomial.
- *
- * We use all-ones as the initial register contents and final bit inversion.
- * This is the same algorithm used e.g. in iSCSI. See RFC 3385 for more
- * details on the choice of polynomial.
- *
- * On big-endian systems, the intermediate value is kept in reverse byte
- * order, to avoid byte-swapping during the calculation. FIN_CRC32C reverses
- * the bytes to the final order.
- */
-#define INIT_CRC32C(crc) ((crc) = 0xFFFFFFFF)
-#ifdef WORDS_BIGENDIAN
-#define FIN_CRC32C(crc)	((crc) = BSWAP32(crc) ^ 0xFFFFFFFF)
-#else
-#define FIN_CRC32C(crc)	((crc) ^= 0xFFFFFFFF)
-#endif
-#define COMP_CRC32C(crc, data, len)	\
-	((crc) = pg_comp_crc32c((crc), (data), (len)))
-#define EQ_CRC32C(c1, c2) ((c1) == (c2))
-
-extern pg_crc32 pg_comp_crc32c(pg_crc32 crc, const void *data, size_t len);
-
-/*
- * CRC-32, the same used e.g. in Ethernet.
- *
- * This is currently only used in ltree and hstore contrib modules. It uses
- * the same lookup table as the legacy algorithm below. New code should
- * use the Castagnoli version instead.
- */
-#define INIT_TRADITIONAL_CRC32(crc) ((crc) = 0xFFFFFFFF)
-#define FIN_TRADITIONAL_CRC32(crc)	((crc) ^= 0xFFFFFFFF)
-#define COMP_TRADITIONAL_CRC32(crc, data, len)	\
-	COMP_CRC32_NORMAL_TABLE(crc, data, len, pg_crc32_table)
-#define EQ_TRADITIONAL_CRC32(c1, c2) ((c1) == (c2))
-
-/* Sarwate's algorithm, for use with a "normal" lookup table */
-#define COMP_CRC32_NORMAL_TABLE(crc, data, len, table)			  \
-do {															  \
-	const unsigned char *__data = (const unsigned char *) (data); \
-	uint32		__len = (len); \
-\
-	while (__len-- > 0) \
-	{ \
-		int		__tab_index = ((int) (crc) ^ *__data++) & 0xFF; \
-		(crc) = table[__tab_index] ^ ((crc) >> 8); \
-	} \
-} while (0)
-
-/*
- * The CRC algorithm used for WAL et al in pre-9.5 versions.
- *
- * This closely resembles the normal CRC-32 algorithm, but is subtly
- * different. Using Williams' terms, we use the "normal" table, but with
- * "reflected" code. That's bogus, but it was like that for years before
- * anyone noticed. It does not correspond to any polynomial in a normal CRC
- * algorithm, so it's not clear what the error-detection properties of this
- * algorithm actually are.
- *
- * We still need to carry this around because it is used in a few on-disk
- * structures that need to be pg_upgradeable. It should not be used in new
- * code.
- */
-#define INIT_LEGACY_CRC32(crc) ((crc) = 0xFFFFFFFF)
-#define FIN_LEGACY_CRC32(crc)	((crc) ^= 0xFFFFFFFF)
-#define COMP_LEGACY_CRC32(crc, data, len)	\
-	COMP_CRC32_REFLECTED_TABLE(crc, data, len, pg_crc32_table)
-#define EQ_LEGACY_CRC32(c1, c2) ((c1) == (c2))
-
-/*
- * Sarwate's algorithm, for use with a "reflected" lookup table (but in the
- * legacy algorithm, we actually use it on a "normal" table, see above)
- */
-#define COMP_CRC32_REFLECTED_TABLE(crc, data, len, table) \
-do {															  \
-	const unsigned char *__data = (const unsigned char *) (data); \
-	uint32		__len = (len); \
-\
-	while (__len-- > 0) \
-	{ \
-		int		__tab_index = ((int) ((crc) >> 24) ^ *__data++) & 0xFF;	\
-		(crc) = table[__tab_index] ^ ((crc) << 8); \
-	} \
-} while (0)
-
-/* Constant tables for CRC-32C and CRC-32 polynomials */
-extern CRCDLLIMPORT const uint32 pg_crc32c_table[8][256];
-extern CRCDLLIMPORT const uint32 pg_crc32_table[256];
-
-#endif   /* PG_CRC_H */