glibc/sysdeps/alpha/string-shift.h
Richard Henderson 120ad6ed1a alpha: Add string-fza, string-fzb.h, string-fzi.h, and string-shift.h
While alpha has the more important string functions in assembly,
there are still a few for find the generic routines are used.

Use the CMPBGE insn, via the builtin, for testing of zeros.  Use a
simplified expansion of __builtin_ctz when the insn isn't available.

Checked on alpha-linux-gnu.

Co-authored-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-02-06 16:19:35 -03:00

45 lines
1.4 KiB
C

/* Shift unaligned word read. Alpha version.
Copyright (C) 2023 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_SHIFT_H
#define _STRING_SHIFT_H 1
#include <limits.h>
#include <stdint.h>
#include <string-fza.h>
/* Return the mask WORD shifted based on S_INT address value, to ignore
values not presented in the aligned word read. */
static __always_inline find_t
shift_find (find_t word, uintptr_t s)
{
return word >> (s % sizeof (op_t));
}
/* Mask off the bits defined the the S alignment value. */
static __always_inline find_t
shift_find_last (find_t word, uintptr_t s)
{
s = s % sizeof (op_t);
if (s == 0)
return word;
return word & ~((op_t)-1 << s);
}
#endif /* _STRING_SHIFT_H */