1/* Return classification value corresponding to argument. 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 26int 27__fpclassify (double x) 28{ 29 u_int32_t hx, lx; 30 int retval = FP_NORMAL; 31 32 EXTRACT_WORDS (hx, lx, x); 33 lx |= hx & 0xfffff; 34 hx &= 0x7ff00000; 35 if ((hx | lx) == 0) 36 retval = FP_ZERO; 37 else if (hx == 0) 38 retval = FP_SUBNORMAL; 39 else if (hx == 0x7ff00000) 40 retval = lx != 0 ? FP_NAN : FP_INFINITE; 41 42 return retval; 43} 44