paritysi2.c 755 B

123456789101112131415161718192021222324252627
  1. /* ===-- paritysi2.c - Implement __paritysi2 -------------------------------===
  2. *
  3. * The LLVM Compiler Infrastructure
  4. *
  5. * This file is dual licensed under the MIT and the University of Illinois Open
  6. * Source Licenses. See LICENSE.TXT for details.
  7. *
  8. * ===----------------------------------------------------------------------===
  9. *
  10. * This file implements __paritysi2 for the compiler_rt library.
  11. *
  12. * ===----------------------------------------------------------------------===
  13. */
  14. #include "int_lib.h"
  15. /* Returns: 1 if number of bits is odd else returns 0 */
  16. COMPILER_RT_ABI si_int
  17. __paritysi2(si_int a)
  18. {
  19. su_int x = (su_int)a;
  20. x ^= x >> 16;
  21. x ^= x >> 8;
  22. x ^= x >> 4;
  23. return (0x6996 >> (x & 0xF)) & 1;
  24. }