s_rintf.c 1.6 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051
  1. /* Copyright (C) 2000-2026 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Lesser General Public
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library. If not, see
  13. <https://www.gnu.org/licenses/>. */
  14. #define NO_MATH_REDIRECT
  15. #include <math.h>
  16. #include <libm-alias-float.h>
  17. float
  18. __rintf (float x)
  19. {
  20. if (isnanf (x))
  21. return x + x;
  22. if (isless (fabsf (x), 16777216.0f)) /* 1 << FLT_MANT_DIG */
  23. {
  24. /* Note that Alpha S_Floating is stored in registers in a
  25. restricted T_Floating format, so we don't even need to
  26. convert back to S_Floating in the end. The initial
  27. conversion to T_Floating is needed to handle denormals. */
  28. float tmp1, tmp2, new_x;
  29. __asm ("cvtst/s %3,%2\n\t"
  30. "cvttq/svid %2,%1\n\t"
  31. "cvtqt/d %1,%0\n\t"
  32. : "=f"(new_x), "=&f"(tmp1), "=&f"(tmp2)
  33. : "f"(x));
  34. /* rint(-0.1) == -0, and in general we'll always have the same
  35. sign as our input. */
  36. x = copysignf(new_x, x);
  37. }
  38. return x;
  39. }
  40. libm_alias_float (__rint, rint)