cosmopolitan/third_party/compiler_rt/paritysi2.c

31 lines
845 B
C

/* clang-format off */
/* ===-- paritysi2.c - Implement __paritysi2 -------------------------------===
*
* The LLVM Compiler Infrastructure
*
* This file is dual licensed under the MIT and the University of Illinois Open
* Source Licenses. See LICENSE.TXT for details.
*
* ===----------------------------------------------------------------------===
*
* This file implements __paritysi2 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
STATIC_YOINK("huge_compiler_rt_license");
#include "third_party/compiler_rt/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;
}