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pg_crc32c_loongarch.c
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1 /*-------------------------------------------------------------------------
2  *
3  * pg_crc32c_loongarch.c
4  * Compute CRC-32C checksum using LoongArch CRCC instructions
5  *
6  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/port/pg_crc32c_loongarch.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 #include "c.h"
16 
17 #include "port/pg_crc32c.h"
18 
21 {
22  const unsigned char *p = data;
23  const unsigned char *pend = p + len;
24 
25  /*
26  * LoongArch doesn't require alignment, but aligned memory access is
27  * significantly faster. Process leading bytes so that the loop below
28  * starts with a pointer aligned to eight bytes.
29  */
30  if (!PointerIsAligned(p, uint16) &&
31  p + 1 <= pend)
32  {
33  crc = __builtin_loongarch_crcc_w_b_w(*p, crc);
34  p += 1;
35  }
36  if (!PointerIsAligned(p, uint32) &&
37  p + 2 <= pend)
38  {
39  crc = __builtin_loongarch_crcc_w_h_w(*(uint16 *) p, crc);
40  p += 2;
41  }
42  if (!PointerIsAligned(p, uint64) &&
43  p + 4 <= pend)
44  {
45  crc = __builtin_loongarch_crcc_w_w_w(*(uint32 *) p, crc);
46  p += 4;
47  }
48 
49  /* Process eight bytes at a time, as far as we can. */
50  while (p + 8 <= pend)
51  {
52  crc = __builtin_loongarch_crcc_w_d_w(*(uint64 *) p, crc);
53  p += 8;
54  }
55 
56  /* Process remaining 0-7 bytes. */
57  if (p + 4 <= pend)
58  {
59  crc = __builtin_loongarch_crcc_w_w_w(*(uint32 *) p, crc);
60  p += 4;
61  }
62  if (p + 2 <= pend)
63  {
64  crc = __builtin_loongarch_crcc_w_h_w(*(uint16 *) p, crc);
65  p += 2;
66  }
67  if (p < pend)
68  {
69  crc = __builtin_loongarch_crcc_w_b_w(*p, crc);
70  }
71 
72  return crc;
73 }
unsigned short uint16
Definition: c.h:492
unsigned int uint32
Definition: c.h:493
#define PointerIsAligned(pointer, type)
Definition: c.h:756
uint32 pg_crc32c
Definition: pg_crc32c.h:38
pg_crc32c pg_comp_crc32c_loongarch(pg_crc32c crc, const void *data, size_t len)
const void size_t len
const void * data
return crc
const unsigned char * pend