xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/parityti2.c (revision 43a5ec4eb41567cc92586503212743d89686d78f)
1 //===-- parityti2.c - Implement __parityti2 -------------------------------===//
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 __parityti2 for the compiler_rt library.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "int_lib.h"
14 
15 #ifdef CRT_HAS_128BIT
16 
17 // Returns: 1 if number of bits is odd else returns 0
18 
19 COMPILER_RT_ABI int __parityti2(ti_int a) {
20   twords x;
21   dwords x2;
22   x.all = a;
23   x2.all = x.s.high ^ x.s.low;
24   su_int x3 = x2.s.high ^ x2.s.low;
25   x3 ^= x3 >> 16;
26   x3 ^= x3 >> 8;
27   x3 ^= x3 >> 4;
28   return (0x6996 >> (x3 & 0xF)) & 1;
29 }
30 
31 #endif // CRT_HAS_128BIT
32