mirror of
https://sourceware.org/git/glibc.git
synced 2024-09-20 00:19:57 +00:00
120ad6ed1a
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>
61 lines
1.8 KiB
C
61 lines
1.8 KiB
C
/* Basic zero byte detection. Generic C 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_FZA_H
|
|
#define _STRING_FZA_H 1
|
|
|
|
#include <string-misc.h>
|
|
#include <string-optype.h>
|
|
|
|
/* The CMPBGE instruction creates a bit mask rather than a byte mask.
|
|
However, if we narrow find_t to either 'int' or 'uint8_t', we get
|
|
unnecessary truncation instructions from the 'unsigned long' type
|
|
returned by __builtin_alpha_cmpbge. */
|
|
typedef op_t find_t;
|
|
|
|
static __always_inline find_t
|
|
find_zero_all (op_t x)
|
|
{
|
|
return __builtin_alpha_cmpbge (0, x);
|
|
}
|
|
|
|
static __always_inline find_t
|
|
find_eq_all (op_t x1, op_t x2)
|
|
{
|
|
return find_zero_all (x1 ^ x2);
|
|
}
|
|
|
|
static __always_inline find_t
|
|
find_zero_eq_all (op_t x1, op_t x2)
|
|
{
|
|
return find_zero_all (x1) | find_zero_all (x1 ^ x2);
|
|
}
|
|
|
|
static __always_inline find_t
|
|
find_zero_ne_all (op_t x1, op_t x2)
|
|
{
|
|
return find_zero_all (x1) | (find_zero_all (x1 ^ x2) ^ 0xff);
|
|
}
|
|
|
|
/* Define the "inexact" versions in terms of the exact versions. */
|
|
#define find_zero_low find_zero_all
|
|
#define find_eq_low find_eq_all
|
|
#define find_zero_eq_low find_zero_eq_all
|
|
|
|
#endif /* _STRING_FZA_H */
|