xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/paritysi2.c (revision 6be3386466ab79a84b48429ae66244f21526d3df)
1 //===-- paritysi2.c - Implement __paritysi2 -------------------------------===//
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 __paritysi2 for the compiler_rt library.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "int_lib.h"
14 
15 // Returns: 1 if number of bits is odd else returns 0
16 
17 COMPILER_RT_ABI int __paritysi2(si_int a) {
18   su_int x = (su_int)a;
19   x ^= x >> 16;
20   x ^= x >> 8;
21   x ^= x >> 4;
22   return (0x6996 >> (x & 0xF)) & 1;
23 }
24