xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/paritysi2.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1*0b57cec5SDimitry Andric //===-- paritysi2.c - Implement __paritysi2 -------------------------------===//
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 __paritysi2 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: 1 if number of bits is odd else returns 0
16*0b57cec5SDimitry Andric 
17*0b57cec5SDimitry Andric COMPILER_RT_ABI si_int __paritysi2(si_int a) {
18*0b57cec5SDimitry Andric   su_int x = (su_int)a;
19*0b57cec5SDimitry Andric   x ^= x >> 16;
20*0b57cec5SDimitry Andric   x ^= x >> 8;
21*0b57cec5SDimitry Andric   x ^= x >> 4;
22*0b57cec5SDimitry Andric   return (0x6996 >> (x & 0xF)) & 1;
23*0b57cec5SDimitry Andric }
24