[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / tile / lib / strlen_64.c

/*
 * Copyright 2011 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>
#include "string-endian.h"

size_t strlen(const char *s)
{
	/* Get an aligned pointer. */
	const uintptr_t s_int = (uintptr_t) s;
	const uint64_t *p = (const uint64_t *)(s_int & -8);

	/* Read and MASK the first word. */
	uint64_t v = *p | MASK(s_int);

	uint64_t bits;
	while ((bits = __insn_v1cmpeqi(v, 0)) == 0)
		v = *++p;

	return ((const char *)p) + (CFZ(bits) >> 3) - s;
}
EXPORT_SYMBOL(strlen);
Commit	Line	Data
18aecc2b CM	1	/*
	2	* Copyright 2011 Tilera Corporation. All Rights Reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation, version 2.
	7	*
	8	* This program is distributed in the hope that it will be useful, but
	9	* WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
	11	* NON INFRINGEMENT. See the GNU General Public License for
	12	* more details.
	13	*/
	14
	15	#include <linux/types.h>
	16	#include <linux/string.h>
	17	#include <linux/module.h>
1efea40d	18	#include "string-endian.h"
18aecc2b CM	19
	20	size_t strlen(const char *s)
	21	{
	22	/* Get an aligned pointer. */
	23	const uintptr_t s_int = (uintptr_t) s;
	24	const uint64_t p = (const uint64_t )(s_int & -8);
	25
1efea40d CM	26	/* Read and MASK the first word. */
1efea40d CM	27	uint64_t v = *p \| MASK(s_int);
18aecc2b CM	28
	29	uint64_t bits;
	30	while ((bits = __insn_v1cmpeqi(v, 0)) == 0)
	31	v = *++p;
	32
1efea40d	33	return ((const char *)p) + (CFZ(bits) >> 3) - s;
18aecc2b CM	34	}
18aecc2b CM	35	EXPORT_SYMBOL(strlen);