1 /* ===-- absvsi2.c - Implement __absvsi2 -----------------------------------===
2 *
3 * The LLVM Compiler Infrastructure
4 *
5 * This file is distributed under the University of Illinois Open Source
6 * License. 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 #include <stdlib.h>
17
18 /* Returns: absolute value */
19
20 /* Effects: aborts if abs(x) < 0 */
21
22 si_int
__absvsi2(si_int a)23 __absvsi2(si_int a)
24 {
25 const int N = (int)(sizeof(si_int) * CHAR_BIT);
26 if (a == (1 << (N-1)))
27 abort();
28 const si_int t = a >> (N - 1);
29 return (a ^ t) - t;
30 }
31