| 0,0 → 1,66 |
|---|
| /* |
| * Copyright (C) 2006 Ondrej Palkovsky |
| * 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. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. |
| */ |
| |
| #ifndef _BITOPS_H_ |
| #define _BITOPS_H_ |
| |
| #include <typedefs.h> |
| |
| |
| /** Return position of first non-zero bit from left. |
| * |
| * If number is zero, it returns 0 |
| */ |
| static inline int fnzb32(__u32 arg) |
| { |
| int n = 0; |
| |
| if (arg & 0xffff0000) { arg >>= 16;n += 16;} |
| if (arg & 0xff00) { arg >>= 8; n += 8;} |
| if (arg & 0xf0) { arg >>= 4; n += 4;} |
| if (arg & 0xc) { arg >>= 2; n+=2;} |
| if (arg & 0x2) { arg >>= 1; n+=1;} |
| return n; |
| } |
| |
| static inline int fnzb64(__u64 arg) |
| { |
| int n = 0; |
| |
| /* This is because mips complains about big numbers, |
| * other platforms should optimize it out */ |
| __u64 oper = 0xffffffff; |
| oper <<= 32; |
| |
| if (arg & oper) { arg >>= 32;n += 32;} |
| return n + fnzb32((__u32) arg); |
| } |
| |
| #define fnzb(x) fnzb32(x) |
| |
| #endif |