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      1      1.1  joerg /* ===-- clzti2.c - Implement __clzti2 -------------------------------------===
      2      1.1  joerg  *
      3      1.1  joerg  *      	       The LLVM Compiler Infrastructure
      4      1.1  joerg  *
      5      1.1  joerg  * This file is dual licensed under the MIT and the University of Illinois Open
      6      1.1  joerg  * Source Licenses. See LICENSE.TXT for details.
      7      1.1  joerg  *
      8      1.1  joerg  * ===----------------------------------------------------------------------===
      9      1.1  joerg  *
     10      1.1  joerg  * This file implements __clzti2 for the compiler_rt library.
     11      1.1  joerg  *
     12      1.1  joerg  * ===----------------------------------------------------------------------===
     13      1.1  joerg  */
     14      1.1  joerg 
     15      1.1  joerg #include "int_lib.h"
     16      1.1  joerg 
     17      1.1  joerg #ifdef CRT_HAS_128BIT
     18      1.1  joerg 
     19      1.1  joerg /* Returns: the number of leading 0-bits */
     20      1.1  joerg 
     21      1.1  joerg /* Precondition: a != 0 */
     22      1.1  joerg 
     23  1.1.1.2  joerg COMPILER_RT_ABI si_int
     24      1.1  joerg __clzti2(ti_int a)
     25      1.1  joerg {
     26      1.1  joerg     twords x;
     27      1.1  joerg     x.all = a;
     28      1.1  joerg     const di_int f = -(x.s.high == 0);
     29      1.1  joerg     return __builtin_clzll((x.s.high & ~f) | (x.s.low & f)) +
     30      1.1  joerg            ((si_int)f & ((si_int)(sizeof(di_int) * CHAR_BIT)));
     31      1.1  joerg }
     32      1.1  joerg 
     33      1.1  joerg #endif /* CRT_HAS_128BIT */
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