xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/absvdi2.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1*0b57cec5SDimitry Andric //===-- absvdi2.c - Implement __absvdi2 -----------------------------------===//
2*0b57cec5SDimitry Andric //
3*0b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*0b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
5*0b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*0b57cec5SDimitry Andric //
7*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
8*0b57cec5SDimitry Andric //
9*0b57cec5SDimitry Andric // This file implements __absvdi2 for the compiler_rt library.
10*0b57cec5SDimitry Andric //
11*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
12*0b57cec5SDimitry Andric 
13*0b57cec5SDimitry Andric #include "int_lib.h"
14*0b57cec5SDimitry Andric 
15*0b57cec5SDimitry Andric // Returns: absolute value
16*0b57cec5SDimitry Andric 
17*0b57cec5SDimitry Andric // Effects: aborts if abs(x) < 0
18*0b57cec5SDimitry Andric 
19*0b57cec5SDimitry Andric COMPILER_RT_ABI di_int __absvdi2(di_int a) {
20*0b57cec5SDimitry Andric   const int N = (int)(sizeof(di_int) * CHAR_BIT);
21*0b57cec5SDimitry Andric   if (a == ((di_int)1 << (N - 1)))
22*0b57cec5SDimitry Andric     compilerrt_abort();
23*0b57cec5SDimitry Andric   const di_int t = a >> (N - 1);
24*0b57cec5SDimitry Andric   return (a ^ t) - t;
25*0b57cec5SDimitry Andric }
26