mathinline.h 2.0 KB

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  1. /* Inline math functions for x86-64.
  2. Copyright (C) 2002, 2003, 2004, 2007, 2009 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. Contributed by Andreas Jaeger <aj@suse.de>, 2002.
  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. #ifndef _MATH_H
  18. # error "Never use <bits/mathinline.h> directly; include <math.h> instead."
  19. #endif
  20. #include <bits/wordsize.h>
  21. #ifndef __extern_inline
  22. # define __MATH_INLINE __inline
  23. #else
  24. # define __MATH_INLINE __extern_inline
  25. #endif
  26. #if defined __USE_ISOC99 && defined __GNUC__ && __GNUC__ >= 2
  27. /* Test for negative number. Used in the signbit() macro. */
  28. __MATH_INLINE int
  29. __NTH (__signbitf (float __x))
  30. {
  31. #if __WORDSIZE == 32
  32. __extension__ union { float __f; int __i; } __u = { __f: __x };
  33. return __u.__i < 0;
  34. #else
  35. int __m;
  36. __asm ("pmovmskb %1, %0" : "=r" (__m) : "x" (__x));
  37. return __m & 0x8;
  38. #endif
  39. }
  40. __MATH_INLINE int
  41. __NTH (__signbit (double __x))
  42. {
  43. #if __WORDSIZE == 32
  44. __extension__ union { double __d; int __i[2]; } __u = { __d: __x };
  45. return __u.__i[1] < 0;
  46. #else
  47. int __m;
  48. __asm ("pmovmskb %1, %0" : "=r" (__m) : "x" (__x));
  49. return __m & 0x80;
  50. #endif
  51. }
  52. __MATH_INLINE int
  53. __NTH (__signbitl (long double __x))
  54. {
  55. __extension__ union { long double __l; int __i[3]; } __u = { __l: __x };
  56. return (__u.__i[2] & 0x8000) != 0;
  57. }
  58. #endif