1 /* integer_length - find most significant bit in an unsigned integer. 2 Copyright (C) 2011-2021 Free Software Foundation, Inc. 3 4 This file is free software: you can redistribute it and/or modify 5 it under the terms of the GNU Lesser General Public License as 6 published by the Free Software Foundation; either version 2.1 of the 7 License, or (at your option) any later version. 8 9 This file is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public License 15 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 16 17 /* Written by Bruno Haible <bruno@clisp.org>, 2011. */ 18 19 #ifndef _INTEGER_LENGTH_H 20 #define _INTEGER_LENGTH_H 21 22 #ifdef __cplusplus 23 extern "C" { 24 #endif 25 26 /* These functions return the minimum number of bits required to represent 27 the given unsigned integer. 28 For non-zero values, this is the position of the most significant bit 29 that is set, plus one. For zero, it is 0. */ 30 31 /* Returns the integer length of x. 32 The result is >= 0, <= sizeof (unsigned int) * CHAR_BIT. */ 33 extern int integer_length (unsigned int x); 34 35 /* Returns the integer length of x. 36 The result is >= 0, <= sizeof (unsigned long) * CHAR_BIT. */ 37 extern int integer_length_l (unsigned long x); 38 39 /* Returns the integer length of x. 40 The result is >= 0, <= sizeof (unsigned long long) * CHAR_BIT. */ 41 extern int integer_length_ll (unsigned long long x); 42 43 #ifdef __cplusplus 44 } 45 #endif 46 47 #endif /* _INTEGER_LENGTH_H */