1 //===-- absvsi2.c - Implement __absvsi2 -----------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements __absvsi2 for the compiler_rt library.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "int_lib.h"
14
15 // Returns: absolute value
16
17 // Effects: aborts if abs(x) < 0
18
__absvsi2(si_int a)19 COMPILER_RT_ABI si_int __absvsi2(si_int a) {
20 const int N = (int)(sizeof(si_int) * CHAR_BIT);
21 if (a == ((si_int)1 << (N - 1)))
22 compilerrt_abort();
23 const si_int t = a >> (N - 1);
24 return (a ^ t) - t;
25 }
26