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- /*
- * Copyright (c) 2014 Richard Braun.
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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, see <http://www.gnu.org/licenses/>.
- *
- *
- * Integer base 2 logarithm operations.
- */
-
- #ifndef _KERN_LOG2_H
- #define _KERN_LOG2_H
- #include <kern/assert.h>
- #ifdef __LP64__
- #define LONG_BIT 64
- #else /* __LP64__ */
- #define LONG_BIT 32
- #endif /* __LP64__ */
- static inline unsigned int
- gnumach_ilog2(unsigned long x)
- {
- assert(x != 0);
- return LONG_BIT - __builtin_clzl(x) - 1;
- }
- static inline unsigned int
- gnumach_iorder2(unsigned long size)
- {
- assert(size != 0);
- if (size == 1)
- return 0;
- return gnumach_ilog2(size - 1) + 1;
- }
- #endif /* _KERN_LOG2_H */
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