xref: /openbsd-src/gnu/llvm/compiler-rt/lib/builtins/absvti2.c (revision 3cab2bb3f667058bece8e38b12449a63a9d73c4b)
1*3cab2bb3Spatrick //===-- absvti2.c - Implement __absvdi2 -----------------------------------===//
2*3cab2bb3Spatrick //
3*3cab2bb3Spatrick // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*3cab2bb3Spatrick // See https://llvm.org/LICENSE.txt for license information.
5*3cab2bb3Spatrick // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*3cab2bb3Spatrick //
7*3cab2bb3Spatrick //===----------------------------------------------------------------------===//
8*3cab2bb3Spatrick //
9*3cab2bb3Spatrick // This file implements __absvti2 for the compiler_rt library.
10*3cab2bb3Spatrick //
11*3cab2bb3Spatrick //===----------------------------------------------------------------------===//
12*3cab2bb3Spatrick 
13*3cab2bb3Spatrick #include "int_lib.h"
14*3cab2bb3Spatrick 
15*3cab2bb3Spatrick #ifdef CRT_HAS_128BIT
16*3cab2bb3Spatrick 
17*3cab2bb3Spatrick // Returns: absolute value
18*3cab2bb3Spatrick 
19*3cab2bb3Spatrick // Effects: aborts if abs(x) < 0
20*3cab2bb3Spatrick 
__absvti2(ti_int a)21*3cab2bb3Spatrick COMPILER_RT_ABI ti_int __absvti2(ti_int a) {
22*3cab2bb3Spatrick   const int N = (int)(sizeof(ti_int) * CHAR_BIT);
23*3cab2bb3Spatrick   if (a == ((ti_int)1 << (N - 1)))
24*3cab2bb3Spatrick     compilerrt_abort();
25*3cab2bb3Spatrick   const ti_int s = a >> (N - 1);
26*3cab2bb3Spatrick   return (a ^ s) - s;
27*3cab2bb3Spatrick }
28*3cab2bb3Spatrick 
29*3cab2bb3Spatrick #endif // CRT_HAS_128BIT
30