linux-hardened/fs/btrfs/math.h
David Sterba f8c269d722 btrfs: cleanup 64bit/32bit divs, compile time constants
Switch to div_u64 if the divisor is a numeric constant or sum of
sizeof()s. We can remove a few instances of do_div that has the hidden
semtantics of changing the 1st argument.

Small power-of-two divisors are converted to bitshifts, large values are
kept intact for clarity.

Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-03 17:23:57 +01:00

42 lines
1.1 KiB
C

/*
* Copyright (C) 2012 Fujitsu. All rights reserved.
* Written by Miao Xie <miaox@cn.fujitsu.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* 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. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#ifndef __BTRFS_MATH_H
#define __BTRFS_MATH_H
#include <asm/div64.h>
static inline u64 div_factor(u64 num, int factor)
{
if (factor == 10)
return num;
num *= factor;
return div_u64(num, 10);
}
static inline u64 div_factor_fine(u64 num, int factor)
{
if (factor == 100)
return num;
num *= factor;
return div_u64(num, 100);
}
#endif