Remove support for 64-bit CRC.

It hasn't been used for anything for a long time.

src/include/utils/pg_crc.h

@@ -10,9 +10,6 @@
  * We use a normal (not "reflected", in Williams' terms) CRC, using initial
  * all-ones register contents and a final bit inversion.
  *
- * The 64-bit variant is not used as of PostgreSQL 8.1, but we retain the
- * code for possible future use.
- *
  *
  * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
@@ -56,97 +53,4 @@ do { \
 /* Constant table for CRC calculation */
 extern CRCDLLIMPORT const uint32 pg_crc32_table[];
 
-
-#ifdef PROVIDE_64BIT_CRC
-
-/*
- * If we use a 64-bit integer type, then a 64-bit CRC looks just like the
- * usual sort of implementation.  However, we can also fake it with two
- * 32-bit registers.  Experience has shown that the two-32-bit-registers code
- * is as fast as, or even much faster than, the 64-bit code on all but true
- * 64-bit machines.  We use SIZEOF_VOID_P to check the native word width.
- */
-
-#if SIZEOF_VOID_P < 8
-
-/*
- * crc0 represents the LSBs of the 64-bit value, crc1 the MSBs.  Note that
- * with crc0 placed first, the output of 32-bit and 64-bit implementations
- * will be bit-compatible only on little-endian architectures.  If it were
- * important to make the two possible implementations bit-compatible on
- * all machines, we could do a configure test to decide how to order the
- * two fields, but it seems not worth the trouble.
- */
-typedef struct pg_crc64
-{
-	uint32		crc0;
-	uint32		crc1;
-}	pg_crc64;
-
-/* Initialize a CRC accumulator */
-#define INIT_CRC64(crc) ((crc).crc0 = 0xffffffff, (crc).crc1 = 0xffffffff)
-
-/* Finish a CRC calculation */
-#define FIN_CRC64(crc)	((crc).crc0 ^= 0xffffffff, (crc).crc1 ^= 0xffffffff)
-
-/* Accumulate some (more) bytes into a CRC */
-#define COMP_CRC64(crc, data, len)	\
-do { \
-	uint32		__crc0 = (crc).crc0; \
-	uint32		__crc1 = (crc).crc1; \
-	unsigned char *__data = (unsigned char *) (data); \
-	uint32		__len = (len); \
-\
-	while (__len-- > 0) \
-	{ \
-		int		__tab_index = ((int) (__crc1 >> 24) ^ *__data++) & 0xFF; \
-		__crc1 = pg_crc64_table1[__tab_index] ^ ((__crc1 << 8) | (__crc0 >> 24)); \
-		__crc0 = pg_crc64_table0[__tab_index] ^ (__crc0 << 8); \
-	} \
-	(crc).crc0 = __crc0; \
-	(crc).crc1 = __crc1; \
-} while (0)
-
-/* Check for equality of two CRCs */
-#define EQ_CRC64(c1,c2)  ((c1).crc0 == (c2).crc0 && (c1).crc1 == (c2).crc1)
-
-/* Constant table for CRC calculation */
-extern CRCDLLIMPORT const uint32 pg_crc64_table0[];
-extern CRCDLLIMPORT const uint32 pg_crc64_table1[];
-#else							/* use int64 implementation */
-
-typedef struct pg_crc64
-{
-	uint64		crc0;
-}	pg_crc64;
-
-/* Initialize a CRC accumulator */
-#define INIT_CRC64(crc) ((crc).crc0 = UINT64CONST(0xffffffffffffffff))
-
-/* Finish a CRC calculation */
-#define FIN_CRC64(crc)	((crc).crc0 ^= UINT64CONST(0xffffffffffffffff))
-
-/* Accumulate some (more) bytes into a CRC */
-#define COMP_CRC64(crc, data, len)	\
-do { \
-	uint64		__crc0 = (crc).crc0; \
-	unsigned char *__data = (unsigned char *) (data); \
-	uint32		__len = (len); \
-\
-	while (__len-- > 0) \
-	{ \
-		int		__tab_index = ((int) (__crc0 >> 56) ^ *__data++) & 0xFF; \
-		__crc0 = pg_crc64_table[__tab_index] ^ (__crc0 << 8); \
-	} \
-	(crc).crc0 = __crc0; \
-} while (0)
-
-/* Check for equality of two CRCs */
-#define EQ_CRC64(c1,c2)  ((c1).crc0 == (c2).crc0)
-
-/* Constant table for CRC calculation */
-extern CRCDLLIMPORT const uint64 pg_crc64_table[];
-#endif   /* SIZEOF_VOID_P < 8 */
-#endif   /* PROVIDE_64BIT_CRC */
-
 #endif   /* PG_CRC_H */