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 | |