glibc/sysdeps/riscv/string-fzi.h

78 lines
1.9 KiB
C

/* Zero byte detection; indexes. RISCV version.
Copyright (C) 2023-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
#ifndef _STRING_RISCV_FZI_H
#define _STRING_RISCV_FZI_H 1
#if defined __riscv_zbb || defined __riscv_xtheadbb
# include <sysdeps/generic/string-fzi.h>
#else
/* Without bitmap clz/ctz extensions, it is faster to direct test the bits
instead of calling compiler auxiliary functions. */
# include <string-optype.h>
static __always_inline unsigned int
index_first (find_t c)
{
if (c & 0x80U)
return 0;
if (c & 0x8000U)
return 1;
if (c & 0x800000U)
return 2;
if (sizeof (op_t) == 4)
return 3;
if (c & 0x80000000U)
return 3;
if (c & 0x8000000000UL)
return 4;
if (c & 0x800000000000UL)
return 5;
if (c & 0x80000000000000UL)
return 6;
return 7;
}
static __always_inline unsigned int
index_last (find_t c)
{
if (sizeof (op_t) == 8)
{
if (c & 0x8000000000000000UL)
return 7;
if (c & 0x80000000000000UL)
return 6;
if (c & 0x800000000000UL)
return 5;
if (c & 0x8000000000UL)
return 4;
}
if (c & 0x80000000U)
return 3;
if (c & 0x800000U)
return 2;
if (c & 0x8000U)
return 1;
return 0;
}
#endif
#endif /* STRING_FZI_H */