diff options
Diffstat (limited to 'libm/s_llrint.c')
| -rw-r--r-- | libm/s_llrint.c | 93 | 
1 files changed, 93 insertions, 0 deletions
| diff --git a/libm/s_llrint.c b/libm/s_llrint.c new file mode 100644 index 000000000..64c870eaa --- /dev/null +++ b/libm/s_llrint.c @@ -0,0 +1,93 @@ +/* Round argument to nearest integral value according to current rounding +   direction. +   Copyright (C) 1997, 2004, 2006 Free Software Foundation, Inc. +   This file is part of the GNU C Library. +   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + +   The GNU C Library is free software; you can redistribute it and/or +   modify it under the terms of the GNU Lesser General Public +   License as published by the Free Software Foundation; either +   version 2.1 of the License, or (at your option) any later version. + +   The GNU C Library is distributed in the hope that it will be useful, +   but WITHOUT ANY WARRANTY; without even the implied warranty of +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU +   Lesser General Public License for more details. + +   You should have received a copy of the GNU Lesser General Public +   License along with the GNU C Library; if not, write to the Free +   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA +   02111-1307 USA.  */ + +#include <math.h> + +#include "math_private.h" + +static const double two52[2] = +{ +  4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */ + -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */ +}; + + +long long int +__llrint (double x) +{ +  int32_t j0; +  u_int32_t i1, i0; +  long long int result; +  volatile double w; +  double t; +  int sx; + +  EXTRACT_WORDS (i0, i1, x); +  j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; +  sx = i0 >> 31; +  i0 &= 0xfffff; +  i0 |= 0x100000; + +  if (j0 < 20) +    { +      w = two52[sx] + x; +      t = w - two52[sx]; +      EXTRACT_WORDS (i0, i1, t); +      j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; +      i0 &= 0xfffff; +      i0 |= 0x100000; + +      result = (j0 < 0 ? 0 : i0 >> (20 - j0)); +    } +  else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1) +    { +      if (j0 >= 52) +	result = (((long long int) i0 << 32) | i1) << (j0 - 52); +      else +	{ +	  w = two52[sx] + x; +	  t = w - two52[sx]; +	  EXTRACT_WORDS (i0, i1, t); +	  j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; +	  i0 &= 0xfffff; +	  i0 |= 0x100000; + +	  if (j0 == 20) +	    result = (long long int) i0; +	  else +	    result = ((long long int) i0 << (j0 - 20)) | (i1 >> (52 - j0)); +	} +    } +  else +    { +      /* The number is too large.  It is left implementation defined +	 what happens.  */ +      return (long long int) x; +    } + +  return sx ? -result : result; +} + +weak_alias (__llrint, llrint) +#ifdef NO_LONG_DOUBLE +strong_alias (__llrint, __llrintl) +weak_alias (__llrint, llrintl) +#endif | 
