pg_crc32c_armv8.c File Reference

#include "c.h"
#include <arm_acle.h>
#include "port/pg_crc32c.h"

Include dependency graph for pg_crc32c_armv8.c:

Go to the source code of this file.

Functions
pg_crc32c	pg_comp_crc32c_armv8 (pg_crc32c crc, const void *data, size_t len)

Function Documentation

pg_comp_crc32c_armv8()

pg_crc32c pg_comp_crc32c_armv8	(	pg_crc32c	crc,
		const void *	data,
		size_t	len
	)

Definition at line 22 of file pg_crc32c_armv8.c.

{
    const unsigned char *p = data;
    const unsigned char *pend = p + len;
 
    /*
     * ARMv8 doesn't require alignment, but aligned memory access is
     * significantly faster. Process leading bytes so that the loop below
     * starts with a pointer aligned to eight bytes.
     */
    if (!PointerIsAligned(p, uint16) &&
        p + 1 <= pend)
    {
        crc = __crc32cb(crc, *p);
        p += 1;
    }
    if (!PointerIsAligned(p, uint32) &&
        p + 2 <= pend)
    {
        crc = __crc32ch(crc, *(uint16 *) p);
        p += 2;
    }
    if (!PointerIsAligned(p, uint64) &&
        p + 4 <= pend)
    {
        crc = __crc32cw(crc, *(uint32 *) p);
        p += 4;
    }
 
    /* Process eight bytes at a time, as far as we can. */
    while (p + 8 <= pend)
    {
        crc = __crc32cd(crc, *(uint64 *) p);
        p += 8;
    }
 
    /* Process remaining 0-7 bytes. */
    if (p + 4 <= pend)
    {
        crc = __crc32cw(crc, *(uint32 *) p);
        p += 4;
    }
    if (p + 2 <= pend)
    {
        crc = __crc32ch(crc, *(uint16 *) p);
        p += 2;
    }
    if (p < pend)
    {
        crc = __crc32cb(crc, *p);
    }
 
    return crc;
}

References crc, data, len, pend, and PointerIsAligned.

Referenced by pg_comp_crc32c_choose(), and pg_crc32c_armv8_available().