48 lines
1.7 KiB
C
48 lines
1.7 KiB
C
/* Copyright (C) 2011-2014 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/>. */
|
|
|
|
/* 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.
|
|
Also, specify how to count "first" and "last" bits
|
|
when the bits have been read as a word. */
|
|
|
|
#include <stdint.h>
|
|
|
|
#ifndef __BIG_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)
|
|
#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)
|
|
#endif
|
|
|
|
/* Create eight copies of the byte in a uint64_t. */
|
|
static inline uint64_t copy_byte(uint8_t byte)
|
|
{
|
|
uint64_t word = byte;
|
|
word = __insn_bfins(word, word, 8, 15);
|
|
word = __insn_bfins(word, word, 16, 31);
|
|
word = __insn_bfins(word, word, 32, 63);
|
|
return word;
|
|
}
|