Home | History | Annotate | Download | only in lib
      1 /* ===-- absvsi2.c - Implement __absvsi2 -----------------------------------===
      2  *
      3  *                     The LLVM Compiler Infrastructure
      4  *
      5  * This file is dual licensed under the MIT and the University of Illinois Open
      6  * Source Licenses. See LICENSE.TXT for details.
      7  *
      8  * ===----------------------------------------------------------------------===
      9  *
     10  * This file implements __absvsi2 for the compiler_rt library.
     11  *
     12  * ===----------------------------------------------------------------------===
     13  */
     14 
     15 #include "int_lib.h"
     16 
     17 /* Returns: absolute value */
     18 
     19 /* Effects: aborts if abs(x) < 0 */
     20 
     21 COMPILER_RT_ABI si_int
     22 __absvsi2(si_int a)
     23 {
     24     const int N = (int)(sizeof(si_int) * CHAR_BIT);
     25     if (a == (1 << (N-1)))
     26         compilerrt_abort();
     27     const si_int t = a >> (N - 1);
     28     return (a ^ t) - t;
     29 }
     30