xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/absvti2.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1*0b57cec5SDimitry Andric //===-- absvti2.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 __absvti2 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 #ifdef CRT_HAS_128BIT
16*0b57cec5SDimitry Andric 
17*0b57cec5SDimitry Andric // Returns: absolute value
18*0b57cec5SDimitry Andric 
19*0b57cec5SDimitry Andric // Effects: aborts if abs(x) < 0
20*0b57cec5SDimitry Andric 
21*0b57cec5SDimitry Andric COMPILER_RT_ABI ti_int __absvti2(ti_int a) {
22*0b57cec5SDimitry Andric   const int N = (int)(sizeof(ti_int) * CHAR_BIT);
23*0b57cec5SDimitry Andric   if (a == ((ti_int)1 << (N - 1)))
24*0b57cec5SDimitry Andric     compilerrt_abort();
25*0b57cec5SDimitry Andric   const ti_int s = a >> (N - 1);
26*0b57cec5SDimitry Andric   return (a ^ s) - s;
27*0b57cec5SDimitry Andric }
28*0b57cec5SDimitry Andric 
29*0b57cec5SDimitry Andric #endif // CRT_HAS_128BIT
30