1/* Round float to integer away from zero. 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 26static const float huge = 1.0e30; 27 28 29float 30__roundf (float x) 31{ 32 int32_t i0, j0; 33 34 GET_FLOAT_WORD (i0, x); 35 j0 = ((i0 >> 23) & 0xff) - 0x7f; 36 if (j0 < 23) 37 { 38 if (j0 < 0) 39 { 40 if (huge + x > 0.0F) 41 { 42 i0 &= 0x80000000; 43 if (j0 == -1) 44 i0 |= 0x3f800000; 45 } 46 } 47 else 48 { 49 u_int32_t i = 0x007fffff >> j0; 50 if ((i0 & i) == 0) 51 /* X is integral. */ 52 return x; 53 if (huge + x > 0.0F) 54 { 55 /* Raise inexact if x != 0. */ 56 i0 += 0x00400000 >> j0; 57 i0 &= ~i; 58 } 59 } 60 } 61 else 62 { 63 if (j0 == 0x80) 64 /* Inf or NaN. */ 65 return x + x; 66 else 67 return x; 68 } 69 70 SET_FLOAT_WORD (x, i0); 71 return x; 72} 73weak_alias (__roundf, roundf) 74