Age         Owner                  TLA  Line data    Source code

                                  1                 : /*-------------------------------------------------------------------------
                                  2                 :  *
                                  3                 :  * pg_crc32c_sse42.c
                                  4                 :  *    Compute CRC-32C checksum using Intel SSE 4.2 instructions.
                                  5                 :  *
                                  6                 :  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
                                  7                 :  * Portions Copyright (c) 1994, Regents of the University of California
                                  8                 :  *
                                  9                 :  *
                                 10                 :  * IDENTIFICATION
                                 11                 :  *    src/port/pg_crc32c_sse42.c
                                 12                 :  *
                                 13                 :  *-------------------------------------------------------------------------
                                 14                 :  */
                                 15                 : #include "c.h"
                                 16                 : 
                                 17                 : #include <nmmintrin.h>
                                 18                 : 
                                 19                 : #include "port/pg_crc32c.h"
                                 20                 : 
                                 21                 : pg_attribute_no_sanitize_alignment()
                                 22                 : pg_crc32c
 2917 heikki.linnakangas         23 CBC    96744744 : pg_comp_crc32c_sse42(pg_crc32c crc, const void *data, size_t len)
                                 24                 : {
                                 25        96744744 :     const unsigned char *p = data;
                                 26        96744744 :     const unsigned char *pend = p + len;
                                 27                 : 
                                 28                 :     /*
                                 29                 :      * Process eight bytes of data at a time.
                                 30                 :      *
                                 31                 :      * NB: We do unaligned accesses here. The Intel architecture allows that,
                                 32                 :      * and performance testing didn't show any performance gain from aligning
                                 33                 :      * the begin address.
                                 34                 :      */
                                 35                 : #ifdef __x86_64__
                                 36      1146943429 :     while (p + 8 <= pend)
                                 37                 :     {
                                 38      1050198685 :         crc = (uint32) _mm_crc32_u64(crc, *((const uint64 *) p));
                                 39      1050198685 :         p += 8;
                                 40                 :     }
                                 41                 : 
                                 42                 :     /* Process remaining full four bytes if any */
                                 43        96744744 :     if (p + 4 <= pend)
                                 44                 :     {
                                 45        61162772 :         crc = _mm_crc32_u32(crc, *((const unsigned int *) p));
                                 46        61162772 :         p += 4;
                                 47                 :     }
                                 48                 : #else
                                 49                 : 
                                 50                 :     /*
                                 51                 :      * Process four bytes at a time. (The eight byte instruction is not
                                 52                 :      * available on the 32-bit x86 architecture).
                                 53                 :      */
                                 54                 :     while (p + 4 <= pend)
                                 55                 :     {
                                 56                 :         crc = _mm_crc32_u32(crc, *((const unsigned int *) p));
                                 57                 :         p += 4;
                                 58                 :     }
                                 59                 : #endif                          /* __x86_64__ */
                                 60                 : 
                                 61                 :     /* Process any remaining bytes one at a time. */
                                 62       202957993 :     while (p < pend)
                                 63                 :     {
                                 64       106213249 :         crc = _mm_crc32_u8(crc, *p);
                                 65       106213249 :         p++;
                                 66                 :     }
                                 67                 : 
                                 68        96744744 :     return crc;
                                 69                 : }