numam-spdk/include/spdk/util.h
Daniel Verkamp b5176ded58 util: add spdk_u32_is_pow2() function
Change-Id: I438053d85360f1c3ecc2b7661dbd573e0217ac46
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/373672
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
2017-08-11 19:36:30 -04:00

88 lines
2.4 KiB
C

/*-
* BSD LICENSE
*
* Copyright (c) Intel Corporation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** \file
* General utility functions
*/
#ifndef SPDK_UTIL_H
#define SPDK_UTIL_H
#include "spdk/stdinc.h"
#ifdef __cplusplus
extern "C" {
#endif
#define spdk_min(a,b) (((a)<(b))?(a):(b))
#define spdk_max(a,b) (((a)>(b))?(a):(b))
#define SPDK_COUNTOF(arr) (sizeof(arr) / sizeof((arr)[0]))
#define SPDK_CONTAINEROF(ptr, type, member) ((type *)((uintptr_t)ptr - offsetof(type, member)))
static inline uint32_t
spdk_u32log2(uint32_t x)
{
if (x == 0) {
/* log(0) is undefined */
return 0;
}
return 31u - __builtin_clz(x);
}
static inline uint32_t
spdk_align32pow2(uint32_t x)
{
return 1u << (1 + spdk_u32log2(x - 1));
}
/**
* Check if a uint32_t is a power of 2.
*/
static inline bool
spdk_u32_is_pow2(uint32_t x)
{
if (x == 0) {
return false;
}
return (x & (x - 1)) == 0;
}
#ifdef __cplusplus
}
#endif
#endif