diff options
Diffstat (limited to 'arch/tile/lib/strlen_32.c')
| -rw-r--r-- | arch/tile/lib/strlen_32.c | 36 | 
1 files changed, 36 insertions, 0 deletions
| diff --git a/arch/tile/lib/strlen_32.c b/arch/tile/lib/strlen_32.c new file mode 100644 index 000000000000..f26f88e11e4a --- /dev/null +++ b/arch/tile/lib/strlen_32.c @@ -0,0 +1,36 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + *   This program is free software; you can redistribute it and/or + *   modify it under the terms of the GNU General Public License + *   as published by the Free Software Foundation, version 2. + * + *   This program 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, GOOD TITLE or + *   NON INFRINGEMENT.  See the GNU General Public License for + *   more details. + */ + +#include <linux/types.h> +#include <linux/string.h> +#include <linux/module.h> + +size_t strlen(const char *s) +{ +	/* Get an aligned pointer. */ +	const uintptr_t s_int = (uintptr_t) s; +	const uint32_t *p = (const uint32_t *)(s_int & -4); + +	/* Read the first word, but force bytes before the string to be nonzero. +	 * This expression works because we know shift counts are taken mod 32. +	 */ +	uint32_t v = *p | ((1 << (s_int << 3)) - 1); + +	uint32_t bits; +	while ((bits = __insn_seqb(v, 0)) == 0) +		v = *++p; + +	return ((const char *)p) + (__insn_ctz(bits) >> 3) - s; +} +EXPORT_SYMBOL(strlen); | 
