llvm-project/compiler-rt/lib/builtins/paritysi2.c

27 lines
768 B
C

/* ===-- paritysi2.c - Implement __paritysi2 -------------------------------===
*
* Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
* See https://llvm.org/LICENSE.txt for license information.
* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
*
* ===----------------------------------------------------------------------===
*
* This file implements __paritysi2 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "int_lib.h"
/* Returns: 1 if number of bits is odd else returns 0 */
COMPILER_RT_ABI si_int
__paritysi2(si_int a)
{
su_int x = (su_int)a;
x ^= x >> 16;
x ^= x >> 8;
x ^= x >> 4;
return (0x6996 >> (x & 0xF)) & 1;
}