w_powf_compat.c 1.9 KB

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  1. /* Copyright (C) 2011-2019 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
  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. #include <math.h>
  16. #include <math_private.h>
  17. #include <math-svid-compat.h>
  18. #include <libm-alias-float.h>
  19. #if LIBM_SVID_COMPAT && SHLIB_COMPAT (libm, GLIBC_2_0, GLIBC_2_27)
  20. /* wrapper powf */
  21. float
  22. __powf_compat (float x, float y)
  23. {
  24. float z = __ieee754_powf (x, y);
  25. if (__glibc_unlikely (!isfinite (z)))
  26. {
  27. if (_LIB_VERSION != _IEEE_)
  28. {
  29. if (isfinite (x) && isfinite (y))
  30. {
  31. if (isnan (z))
  32. /* pow neg**non-int */
  33. return __kernel_standard_f (x, y, 124);
  34. else if (x == 0.0f && y < 0.0f)
  35. {
  36. if (signbit (x) && signbit (z))
  37. /* pow(-0.0,negative) */
  38. return __kernel_standard_f (x, y, 123);
  39. else
  40. /* pow(+0.0,negative) */
  41. return __kernel_standard_f (x, y, 143);
  42. }
  43. else
  44. /* pow overflow */
  45. return __kernel_standard_f (x, y, 121);
  46. }
  47. }
  48. }
  49. else if (__builtin_expect (z == 0.0f, 0)
  50. && isfinite (x) && x != 0 && isfinite (y)
  51. && _LIB_VERSION != _IEEE_)
  52. /* pow underflow */
  53. return __kernel_standard_f (x, y, 122);
  54. return z;
  55. }
  56. compat_symbol (libm, __powf_compat, powf, GLIBC_2_0);
  57. #endif