blob: 1ab8ae0c92a62b6dc0f753bf35d884950dab27e8 [file] [log] [blame]
/*
* Copyright (c) 2008 Travis Geiselbrecht
*
* 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.
*/
#ifndef __POW2_H
#define __POW2_H
#include <sys/types.h>
#include <compiler.h>
/* routines for dealing with power of 2 values for efficiency */
static inline __ALWAYS_INLINE bool ispow2(uint val)
{
return ((val - 1) & val) == 0;
}
static inline __ALWAYS_INLINE uint log2(uint val)
{
if (!ispow2(val))
return 0; // undefined
return __builtin_ctz(val);
}
static inline __ALWAYS_INLINE uint valpow2(uint valp2)
{
return 1 << valp2;
}
static inline __ALWAYS_INLINE uint divpow2(uint val, uint divp2)
{
return val >> divp2;
}
static inline __ALWAYS_INLINE uint modpow2(uint val, uint modp2)
{
return val & ((1UL << modp2) - 1);
}
#endif