mtk-lk/platform/mt6771/bitops.c

/*
 * Copyright (c) 2012 MediaTek Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <platform/bitops.h>

unsigned int uffs(unsigned int x)
{
	unsigned int r = 1;

	if (!x)
		return 0;
	if (!(x & 0xffff)) {
		x >>= 16;
		r += 16;
	}
	if (!(x & 0xff)) {
		x >>= 8;
		r += 8;
	}
	if (!(x & 0xf)) {
		x >>= 4;
		r += 4;
	}
	if (!(x & 3)) {
		x >>= 2;
		r += 2;
	}
	if (!(x & 1)) {
		x >>= 1;
		r += 1;
	}
	return r;
}