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      1  1.1  joerg /* ===-- absvsi2.c - Implement __absvsi2 -----------------------------------===
      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 __absvsi2 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 /* Returns: absolute value */
     18  1.1  joerg 
     19  1.1  joerg /* Effects: aborts if abs(x) < 0 */
     20  1.1  joerg 
     21  1.1  joerg COMPILER_RT_ABI si_int
     22  1.1  joerg __absvsi2(si_int a)
     23  1.1  joerg {
     24  1.1  joerg     const int N = (int)(sizeof(si_int) * CHAR_BIT);
     25  1.1  joerg     if (a == (1 << (N-1)))
     26  1.1  joerg         compilerrt_abort();
     27  1.1  joerg     const si_int t = a >> (N - 1);
     28  1.1  joerg     return (a ^ t) - t;
     29  1.1  joerg }
     30