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      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 __LZCNT__
     29 # error "LZCNT instruction is not enabled"
     30 #endif /* __LZCNT__ */
     31 
     32 #ifndef __LZCNTINTRIN_H
     33 #define __LZCNTINTRIN_H
     34 
     35 static __inline__ unsigned short __attribute__((__always_inline__, __nodebug__))
     36 __lzcnt16(unsigned short __X)
     37 {
     38   return __builtin_clzs(__X);
     39 }
     40 
     41 static __inline__ unsigned int __attribute__((__always_inline__, __nodebug__))
     42 __lzcnt32(unsigned int __X)
     43 {
     44   return __builtin_clz(__X);
     45 }
     46 
     47 #ifdef __x86_64__
     48 static __inline__ unsigned long long __attribute__((__always_inline__, __nodebug__))
     49 __lzcnt64(unsigned long long __X)
     50 {
     51   return __builtin_clzll(__X);
     52 }
     53 #endif
     54 
     55 #endif /* __LZCNTINTRIN_H */
     56