1/* Round double value to long long int. 2 Copyright (C) 1997 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, write to the Free 18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 19 02111-1307 USA. */ 20 21#include <math.h> 22 23#include "math_private.h" 24 25 26long long int 27__llround (double x) 28{ 29 int32_t j0; 30 u_int32_t i1, i0; 31 long long int result; 32 int sign; 33 34 EXTRACT_WORDS (i0, i1, x); 35 j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; 36 sign = (i0 & 0x80000000) != 0 ? -1 : 1; 37 i0 &= 0xfffff; 38 i0 |= 0x100000; 39 40 if (j0 < 20) 41 { 42 if (j0 < 0) 43 return j0 < -1 ? 0 : sign; 44 else 45 { 46 i0 += 0x80000 >> j0; 47 48 result = i0 >> (20 - j0); 49 } 50 } 51 else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1) 52 { 53 if (j0 >= 52) 54 result = (((long long int) i0 << 32) | i1) << (j0 - 52); 55 else 56 { 57 u_int32_t j = i1 + (0x80000000 >> (j0 - 20)); 58 if (j < i1) 59 ++i0; 60 61 if (j0 == 20) 62 result = (long long int) i0; 63 else 64 result = ((long long int) i0 << (j0 - 20)) | (j >> (52 - j0)); 65 } 66 } 67 else 68 { 69 /* The number is too large. It is left implementation defined 70 what happens. */ 71 return (long long int) x; 72 } 73 74 return sign * result; 75} 76 77weak_alias (__llround, llround) 78#ifdef NO_LONG_DOUBLE 79strong_alias (__llround, __llroundl) 80weak_alias (__llround, llroundl) 81#endif 82