moddi3.c 1.0 KB

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  1. /*===-- moddi3.c - Implement __moddi3 -------------------------------------===
  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 __moddi3 for the compiler_rt library.
  11. *
  12. * ===----------------------------------------------------------------------===
  13. */
  14. #include "int_lib.h"
  15. /* Returns: a % b */
  16. COMPILER_RT_ABI di_int
  17. __moddi3(di_int a, di_int b)
  18. {
  19. const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1;
  20. di_int s = b >> bits_in_dword_m1; /* s = b < 0 ? -1 : 0 */
  21. b = (b ^ s) - s; /* negate if s == -1 */
  22. s = a >> bits_in_dword_m1; /* s = a < 0 ? -1 : 0 */
  23. a = (a ^ s) - s; /* negate if s == -1 */
  24. du_int r;
  25. __udivmoddi4(a, b, &r);
  26. return ((di_int)r ^ s) - s; /* negate if s == -1 */
  27. }