mirror of git://sourceware.org/git/glibc.git
59 lines
2.1 KiB
C
59 lines
2.1 KiB
C
/* 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);
|
|
}
|