| Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame^] | 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 | #include "int_lib.h" |
| 15 | #include <stdlib.h> |
| 16 | |
| 17 | // Returns: absolute value |
| 18 | |
| 19 | // Effects: aborts if abs(x) < 0 |
| 20 | |
| 21 | 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 | abort(); |
| 27 | const si_int t = a >> (N - 1); |
| 28 | return (a ^ t) - t; |
| 29 | } |