compiler-rt/lib/builtins/parityti2.c

   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