s_fpclassify.c 1.4 KB

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  1. /* Return classification value corresponding to argument.
  2. Copyright (C) 1997, 2002 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
  5. The GNU C Library is free software; you can redistribute it and/or
  6. modify it under the terms of the GNU Lesser General Public
  7. License as published by the Free Software Foundation; either
  8. version 2.1 of the License, or (at your option) any later version.
  9. The GNU C Library is distributed in the hope that it will be useful,
  10. but WITHOUT ANY WARRANTY; without even the implied warranty of
  11. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12. Lesser General Public License for more details.
  13. You should have received a copy of the GNU Lesser General Public
  14. License along with the GNU C Library; if not, write to the Free
  15. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  16. 02111-1307 USA. */
  17. #include <math.h>
  18. #include "math_private.h"
  19. int
  20. __fpclassify (double x)
  21. {
  22. u_int32_t hx, lx;
  23. int retval = FP_NORMAL;
  24. EXTRACT_WORDS (hx, lx, x);
  25. lx |= hx & 0xfffff;
  26. hx &= 0x7ff00000;
  27. if ((hx | lx) == 0)
  28. retval = FP_ZERO;
  29. else if (hx == 0)
  30. retval = FP_SUBNORMAL;
  31. else if (hx == 0x7ff00000)
  32. retval = lx != 0 ? FP_NAN : FP_INFINITE;
  33. return retval;
  34. }
  35. libm_hidden_def (__fpclassify)