1 /*===---- lzcntintrin.h - LZCNT intrinsics ---------------------------------=== 2 * 3 * Permission is hereby granted, free of charge, to any person obtaining a copy 4 * of this software and associated documentation files (the "Software"), to deal 5 * in the Software without restriction, including without limitation the rights 6 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 7 * copies of the Software, and to permit persons to whom the Software is 8 * furnished to do so, subject to the following conditions: 9 * 10 * The above copyright notice and this permission notice shall be included in 11 * all copies or substantial portions of the Software. 12 * 13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 18 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 19 * THE SOFTWARE. 20 * 21 *===-----------------------------------------------------------------------=== 22 */ 23 24 #if !defined __X86INTRIN_H && !defined __IMMINTRIN_H 25 #error "Never use <lzcntintrin.h> directly; include <x86intrin.h> instead." 26 #endif 27 28 #ifndef __LZCNTINTRIN_H 29 #define __LZCNTINTRIN_H 30 31 /* Define the default attributes for the functions in this file. */ 32 #define __DEFAULT_FN_ATTRS __attribute__((__always_inline__, __nodebug__, __target__("lzcnt"))) 33 34 /// \brief Counts the number of leading zero bits in the operand. 35 /// 36 /// \headerfile <x86intrin.h> 37 /// 38 /// This intrinsic corresponds to the \c LZCNT instruction. 39 /// 40 /// \param __X 41 /// An unsigned 16-bit integer whose leading zeros are to be counted. 42 /// \returns An unsigned 16-bit integer containing the number of leading zero 43 /// bits in the operand. 44 static __inline__ unsigned short __DEFAULT_FN_ATTRS 45 __lzcnt16(unsigned short __X) 46 { 47 return __X ? __builtin_clzs(__X) : 16; 48 } 49 50 /// \brief Counts the number of leading zero bits in the operand. 51 /// 52 /// \headerfile <x86intrin.h> 53 /// 54 /// This intrinsic corresponds to the \c LZCNT instruction. 55 /// 56 /// \param __X 57 /// An unsigned 32-bit integer whose leading zeros are to be counted. 58 /// \returns An unsigned 32-bit integer containing the number of leading zero 59 /// bits in the operand. 60 static __inline__ unsigned int __DEFAULT_FN_ATTRS 61 __lzcnt32(unsigned int __X) 62 { 63 return __X ? __builtin_clz(__X) : 32; 64 } 65 66 /// \brief Counts the number of leading zero bits in the operand. 67 /// 68 /// \headerfile <x86intrin.h> 69 /// 70 /// This intrinsic corresponds to the \c LZCNT instruction. 71 /// 72 /// \param __X 73 /// An unsigned 32-bit integer whose leading zeros are to be counted. 74 /// \returns An unsigned 32-bit integer containing the number of leading zero 75 /// bits in the operand. 76 static __inline__ unsigned int __DEFAULT_FN_ATTRS 77 _lzcnt_u32(unsigned int __X) 78 { 79 return __X ? __builtin_clz(__X) : 32; 80 } 81 82 #ifdef __x86_64__ 83 /// \brief Counts the number of leading zero bits in the operand. 84 /// 85 /// \headerfile <x86intrin.h> 86 /// 87 /// This intrinsic corresponds to the \c LZCNT instruction. 88 /// 89 /// \param __X 90 /// An unsigned 64-bit integer whose leading zeros are to be counted. 91 /// \returns An unsigned 64-bit integer containing the number of leading zero 92 /// bits in the operand. 93 static __inline__ unsigned long long __DEFAULT_FN_ATTRS 94 __lzcnt64(unsigned long long __X) 95 { 96 return __X ? __builtin_clzll(__X) : 64; 97 } 98 99 /// \brief Counts the number of leading zero bits in the operand. 100 /// 101 /// \headerfile <x86intrin.h> 102 /// 103 /// This intrinsic corresponds to the \c LZCNT instruction. 104 /// 105 /// \param __X 106 /// An unsigned 64-bit integer whose leading zeros are to be counted. 107 /// \returns An unsigned 64-bit integer containing the number of leading zero 108 /// bits in the operand. 109 static __inline__ unsigned long long __DEFAULT_FN_ATTRS 110 _lzcnt_u64(unsigned long long __X) 111 { 112 return __X ? __builtin_clzll(__X) : 64; 113 } 114 #endif 115 116 #undef __DEFAULT_FN_ATTRS 117 118 #endif /* __LZCNTINTRIN_H */ 119
