w_tgamma_template.c 1.8 KB

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  1. /* Wrapper to set errno for tgamma.
  2. Copyright (C) 2017-2019 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. The GNU C Library is free software; you can redistribute it and/or
  5. modify it under the terms of the GNU Lesser General Public
  6. License as published by the Free Software Foundation; either
  7. version 2.1 of the License, or (at your option) any later version.
  8. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, see
  14. <http://www.gnu.org/licenses/>. */
  15. /* Only build wrappers from the templates for the types that define the macro
  16. below. This macro is set in math-type-macros-<type>.h in sysdeps/generic
  17. for each floating-point type. */
  18. #if __USE_WRAPPER_TEMPLATE
  19. # include <errno.h>
  20. # include <fenv.h>
  21. # include <math.h>
  22. # include <math_private.h>
  23. #define M_CALL_FUNC_X(x) x ## _r
  24. #define M_CALL_FUNC(x) M_CALL_FUNC_X (x)
  25. FLOAT
  26. M_DECL_FUNC (__tgamma) (FLOAT x)
  27. {
  28. int local_signgam;
  29. FLOAT y = M_CALL_FUNC (M_SUF (__ieee754_gamma)) (x, &local_signgam);
  30. if (__glibc_unlikely (!isfinite (y) || y == 0)
  31. && (isfinite (x) || (isinf (x) && x < 0)))
  32. {
  33. if (x == 0)
  34. /* Pole error: tgamma(x=0). */
  35. __set_errno (ERANGE);
  36. else if (M_SUF (floor) (x) == x && x < 0)
  37. /* Domain error: tgamma(integer x<0). */
  38. __set_errno (EDOM);
  39. else
  40. /* Overflow or underflow. */
  41. __set_errno (ERANGE);
  42. }
  43. return local_signgam < 0 ? -y : y;
  44. }
  45. declare_mgen_alias (__tgamma, tgamma)
  46. #endif /* __USE_WRAPPER_TEMPLATE. */