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
24static const __float128 two112[2] =
25{
26  5.19229685853482762853049632922009600E+33Q, /* 0x406F000000000000, 0 */
27 -5.19229685853482762853049632922009600E+33Q  /* 0xC06F000000000000, 0 */
28};
29
30long long int
31llrintq (__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}
102