blob: fe9b073efba57ff58ab8dc621b4838e328c51863 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
/* Copyright (C) 2011-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
#include <endian.h>
#include <stdint.h>
/* Provide a set of macros to help keep endianness #ifdefs out of
the string functions.
MASK: Provide a mask based on the pointer alignment that
sets up non-zero bytes before the beginning of the string.
The MASK expression works because shift counts are taken mod 64.
NULMASK: Clear bytes beyond a given point in the string.
CFZ: Find the first zero bit in the 8 string bytes in a long.
REVCZ: Find the last zero bit in the 8 string bytes in a long.
STRSHIFT: Shift N bits towards the start of the string. */
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define MASK(x) (__insn_shl(1ULL, (x << 3)) - 1)
#define NULMASK(x) ((2ULL << x) - 1)
#define CFZ(x) __insn_ctz(x)
#define REVCZ(x) __insn_clz(x)
#define STRSHIFT(x,n) ((x) >> n)
#else
#define MASK(x) (__insn_shl(-2LL, ((-x << 3) - 1)))
#define NULMASK(x) (-2LL << (63 - x))
#define CFZ(x) __insn_clz(x)
#define REVCZ(x) __insn_ctz(x)
#define STRSHIFT(x,n) ((x) << n)
#endif
/* Create eight copies of the byte in a uint64_t. Byte Shuffle uses
the bytes of srcB as the index into the dest vector to select a
byte. With all indices of zero, the first byte is copied into all
the other bytes. */
static inline uint64_t copy_byte(uint8_t byte)
{
return __insn_shufflebytes(byte, 0, 0);
}
|
GitWeb
