From c8363af9978e978cb860e0410fe31a39d49a7366 Mon Sep 17 00:00:00 2001 From: Peter Eisentraut Date: Tue, 30 Aug 2016 12:00:00 -0400 Subject: [PATCH 10/27] Reorder some things Forward declarations of static variables are not possible in C++, so move the full definition before its use. --- src/port/pg_crc32c_sb8.c | 136 +++++++++++++++++++++++------------------------ 1 file changed, 67 insertions(+), 69 deletions(-) diff --git a/src/port/pg_crc32c_sb8.c b/src/port/pg_crc32c_sb8.c index 2680e36..c7e03e9 100644 --- a/src/port/pg_crc32c_sb8.c +++ b/src/port/pg_crc32c_sb8.c @@ -22,8 +22,6 @@ #include "port/pg_crc32c.h" -static const uint32 pg_crc32c_table[8][256]; - /* Accumulate one input byte */ #ifdef WORDS_BIGENDIAN #define CRC8(x) pg_crc32c_table[0][((crc >> 24) ^ (x)) & 0xFF] ^ (crc << 8) @@ -31,73 +29,6 @@ static const uint32 pg_crc32c_table[8][256]; #define CRC8(x) pg_crc32c_table[0][(crc ^ (x)) & 0xFF] ^ (crc >> 8) #endif -pg_crc32c -pg_comp_crc32c_sb8(pg_crc32c crc, const void *data, size_t len) -{ - const unsigned char *p = data; - const uint32 *p4; - - /* - * Handle 0-3 initial bytes one at a time, so that the loop below starts - * with a pointer aligned to four bytes. - */ - while (len > 0 && ((uintptr_t) p & 3)) - { - crc = CRC8(*p++); - len--; - } - - /* - * Process eight bytes of data at a time. - */ - p4 = (const uint32 *) p; - while (len >= 8) - { - uint32 a = *p4++ ^ crc; - uint32 b = *p4++; - -#ifdef WORDS_BIGENDIAN - const uint8 c0 = b; - const uint8 c1 = b >> 8; - const uint8 c2 = b >> 16; - const uint8 c3 = b >> 24; - const uint8 c4 = a; - const uint8 c5 = a >> 8; - const uint8 c6 = a >> 16; - const uint8 c7 = a >> 24; -#else - const uint8 c0 = b >> 24; - const uint8 c1 = b >> 16; - const uint8 c2 = b >> 8; - const uint8 c3 = b; - const uint8 c4 = a >> 24; - const uint8 c5 = a >> 16; - const uint8 c6 = a >> 8; - const uint8 c7 = a; -#endif - - crc = - pg_crc32c_table[0][c0] ^ pg_crc32c_table[1][c1] ^ - pg_crc32c_table[2][c2] ^ pg_crc32c_table[3][c3] ^ - pg_crc32c_table[4][c4] ^ pg_crc32c_table[5][c5] ^ - pg_crc32c_table[6][c6] ^ pg_crc32c_table[7][c7]; - - len -= 8; - } - - /* - * Handle any remaining bytes one at a time. - */ - p = (const unsigned char *) p4; - while (len > 0) - { - crc = CRC8(*p++); - len--; - } - - return crc; -} - /* * Lookup tables for the slicing-by-8 algorithm, for the so-called Castagnoli * polynomial (the same that is used e.g. in iSCSI), 0x1EDC6F41. Using @@ -1167,3 +1098,70 @@ static const uint32 pg_crc32c_table[8][256] = { } #endif /* WORDS_BIGENDIAN */ }; + +pg_crc32c +pg_comp_crc32c_sb8(pg_crc32c crc, const void *data, size_t len) +{ + const unsigned char *p = data; + const uint32 *p4; + + /* + * Handle 0-3 initial bytes one at a time, so that the loop below starts + * with a pointer aligned to four bytes. + */ + while (len > 0 && ((uintptr_t) p & 3)) + { + crc = CRC8(*p++); + len--; + } + + /* + * Process eight bytes of data at a time. + */ + p4 = (const uint32 *) p; + while (len >= 8) + { + uint32 a = *p4++ ^ crc; + uint32 b = *p4++; + +#ifdef WORDS_BIGENDIAN + const uint8 c0 = b; + const uint8 c1 = b >> 8; + const uint8 c2 = b >> 16; + const uint8 c3 = b >> 24; + const uint8 c4 = a; + const uint8 c5 = a >> 8; + const uint8 c6 = a >> 16; + const uint8 c7 = a >> 24; +#else + const uint8 c0 = b >> 24; + const uint8 c1 = b >> 16; + const uint8 c2 = b >> 8; + const uint8 c3 = b; + const uint8 c4 = a >> 24; + const uint8 c5 = a >> 16; + const uint8 c6 = a >> 8; + const uint8 c7 = a; +#endif + + crc = + pg_crc32c_table[0][c0] ^ pg_crc32c_table[1][c1] ^ + pg_crc32c_table[2][c2] ^ pg_crc32c_table[3][c3] ^ + pg_crc32c_table[4][c4] ^ pg_crc32c_table[5][c5] ^ + pg_crc32c_table[6][c6] ^ pg_crc32c_table[7][c7]; + + len -= 8; + } + + /* + * Handle any remaining bytes one at a time. + */ + p = (const unsigned char *) p4; + while (len > 0) + { + crc = CRC8(*p++); + len--; + } + + return crc; +} -- 2.9.3