text: /**
   * @file fpclassify.c
   * Copyright 2012, 2013 MinGW.org project
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   * and/or sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following conditions:
   * 
   * The above copyright notice and this permission notice (including the next
   * paragraph) shall be included in all copies or substantial portions of the
   * Software.
   * 
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   * DEALINGS IN THE SOFTWARE.
   */
  #include <math.h>
  
  /* 'fxam' sets FPU flags C3,C2,C0   'fstsw' stores: 
   FP_NAN			001		0x0100
   FP_NORMAL		010		0x0400
   FP_INFINITE		011		0x0500
   FP_ZERO		100		0x4000
   FP_SUBNORMAL		110		0x4400
  
  and sets C1 flag (signbit) if neg */
  
  int __fpclassify (double _x){
    unsigned short sw;
    __asm__ (
  	"fxam; fstsw %%ax;"
  	: "=a" (sw)
  	: "t" (_x)
  	);
    return sw & (FP_NAN | FP_NORMAL | FP_ZERO );
  }
  