1  /* Round argument to nearest integral value according to current rounding
       2     direction.
       3     Copyright (C) 1997-2018 Free Software Foundation, Inc.
       4     This file is part of the GNU C Library.
       5     Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and
       6  		  Jakub Jelinek <jj@ultra.linux.cz>, 1999.
       7  
       8     The GNU C Library is free software; you can redistribute it and/or
       9     modify it under the terms of the GNU Lesser General Public
      10     License as published by the Free Software Foundation; either
      11     version 2.1 of the License, or (at your option) any later version.
      12  
      13     The GNU C Library is distributed in the hope that it will be useful,
      14     but WITHOUT ANY WARRANTY; without even the implied warranty of
      15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      16     Lesser General Public License for more details.
      17  
      18     You should have received a copy of the GNU Lesser General Public
      19     License along with the GNU C Library; if not, see
      20     <http://www.gnu.org/licenses/>.  */
      21  
      22  #include "quadmath-imp.h"
      23  
      24  static const __float128 two112[2] =
      25  {
      26    5.19229685853482762853049632922009600E+33Q, /* 0x406F000000000000, 0 */
      27   -5.19229685853482762853049632922009600E+33Q  /* 0xC06F000000000000, 0 */
      28  };
      29  
      30  long long int
      31  llrintq (__float128 x)
      32  {
      33    int32_t j0;
      34    uint64_t i0,i1;
      35    __float128 w;
      36    __float128 t;
      37    long long int result;
      38    int sx;
      39  
      40    GET_FLT128_WORDS64 (i0, i1, x);
      41    j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
      42    sx = i0 >> 63;
      43    i0 &= 0x0000ffffffffffffLL;
      44    i0 |= 0x0001000000000000LL;
      45  
      46    if (j0 < (int32_t) (8 * sizeof (long long int)) - 1)
      47      {
      48  #if defined FE_INVALID || defined FE_INEXACT
      49        /* X < LLONG_MAX + 1 implied by J0 < 63.  */
      50        if (x > (__float128) LLONG_MAX)
      51  	{
      52  	  /* In the event of overflow we must raise the "invalid"
      53  	     exception, but not "inexact".  */
      54  	  t = nearbyintq (x);
      55  	  feraiseexcept (t == LLONG_MAX ? FE_INEXACT : FE_INVALID);
      56  	}
      57        else
      58  #endif
      59  	{
      60  	  w = two112[sx] + x;
      61  	  t = w - two112[sx];
      62  	}
      63        GET_FLT128_WORDS64 (i0, i1, t);
      64        j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
      65        i0 &= 0x0000ffffffffffffLL;
      66        i0 |= 0x0001000000000000LL;
      67  
      68        if (j0 < 0)
      69  	result = 0;
      70        else if (j0 <= 48)
      71  	result = i0 >> (48 - j0);
      72        else
      73  	result = ((long long int) i0 << (j0 - 48)) | (i1 >> (112 - j0));
      74      }
      75    else
      76      {
      77        /* The number is too large.  Unless it rounds to LLONG_MIN,
      78  	 FE_INVALID must be raised and the return value is
      79  	 unspecified.  */
      80  #if defined FE_INVALID || defined FE_INEXACT
      81        if (x < (__float128) LLONG_MIN
      82  	  && x > (__float128) LLONG_MIN - 1)
      83  	{
      84  	  /* If truncation produces LLONG_MIN, the cast will not raise
      85  	     the exception, but may raise "inexact".  */
      86  	  t = nearbyintq (x);
      87  	  feraiseexcept (t == LLONG_MIN ? FE_INEXACT : FE_INVALID);
      88  	  return LLONG_MIN;
      89  	}
      90        else if (FIX_FLT128_LLONG_CONVERT_OVERFLOW && x != (__float128) LLONG_MIN)
      91  	{
      92  	  feraiseexcept (FE_INVALID);
      93  	  return sx == 0 ? LLONG_MAX : LLONG_MIN;
      94  	}
      95  
      96  #endif
      97        return (long long int) x;
      98      }
      99  
     100    return sx ? -result : result;
     101  }