xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/absvdi2.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 //===-- absvdi2.c - Implement __absvdi2 -----------------------------------===//
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 __absvdi2 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 
__absvdi2(di_int a)19 COMPILER_RT_ABI di_int __absvdi2(di_int a) {
20   const int N = (int)(sizeof(di_int) * CHAR_BIT);
21   if (a == ((di_int)((du_int)1 << (N - 1))))
22     compilerrt_abort();
23   const di_int t = a >> (N - 1);
24   return (a ^ t) - t;
25 }
26