postgresql/src/port/pg_crc32c_loongarch.c

74 lines
1.7 KiB
C

/*-------------------------------------------------------------------------
*
* pg_crc32c_loongarch.c
* Compute CRC-32C checksum using LoongArch CRCC instructions
*
* Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/port/pg_crc32c_loongarch.c
*
*-------------------------------------------------------------------------
*/
#include "c.h"
#include "port/pg_crc32c.h"
pg_crc32c
pg_comp_crc32c_loongarch(pg_crc32c crc, const void *data, size_t len)
{
const unsigned char *p = data;
const unsigned char *pend = p + len;
/*
* LoongArch 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 = __builtin_loongarch_crcc_w_b_w(*p, crc);
p += 1;
}
if (!PointerIsAligned(p, uint32) &&
p + 2 <= pend)
{
crc = __builtin_loongarch_crcc_w_h_w(*(uint16 *) p, crc);
p += 2;
}
if (!PointerIsAligned(p, uint64) &&
p + 4 <= pend)
{
crc = __builtin_loongarch_crcc_w_w_w(*(uint32 *) p, crc);
p += 4;
}
/* Process eight bytes at a time, as far as we can. */
while (p + 8 <= pend)
{
crc = __builtin_loongarch_crcc_w_d_w(*(uint64 *) p, crc);
p += 8;
}
/* Process remaining 0-7 bytes. */
if (p + 4 <= pend)
{
crc = __builtin_loongarch_crcc_w_w_w(*(uint32 *) p, crc);
p += 4;
}
if (p + 2 <= pend)
{
crc = __builtin_loongarch_crcc_w_h_w(*(uint16 *) p, crc);
p += 2;
}
if (p < pend)
{
crc = __builtin_loongarch_crcc_w_b_w(*p, crc);
}
return crc;
}