| /* Round argument to nearest integral value according to current rounding |
| direction. |
| Copyright (C) 1997-2018 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, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <fenv.h> |
| #include <limits.h> |
| #include <math.h> |
| |
| #include <math_private.h> |
| #include <libm-alias-double.h> |
| #include <fix-fp-int-convert-overflow.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; |
| uint32_t i1, i0; |
| long long int result; |
| 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 = math_narrow_eval (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 = math_narrow_eval (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 |
| { |
| #ifdef FE_INVALID |
| /* The number is too large. Unless it rounds to LLONG_MIN, |
| FE_INVALID must be raised and the return value is |
| unspecified. */ |
| if (FIX_DBL_LLONG_CONVERT_OVERFLOW && x != (double) LLONG_MIN) |
| { |
| feraiseexcept (FE_INVALID); |
| return sx == 0 ? LLONG_MAX : LLONG_MIN; |
| } |
| #endif |
| return (long long int) x; |
| } |
| |
| return sx ? -result : result; |
| } |
| |
| libm_alias_double (__llrint, llrint) |