text: /*
   *                               POK header
   * 
   * The following file is a part of the POK project. Any modification should
   * made according to the POK licence. You CANNOT use this file or a part of
   * this file is this part of a file for your own project
   *
   * For more information on the POK licence, please see our LICENCE FILE
   *
   * Please follow the coding guidelines described in doc/CODING_GUIDELINES
   *
   *                                      Copyright (c) 2007-2009 POK team 
   *
   * Created by julien on Fri Jan 30 14:41:34 2009 
   */
  
  /* @(#)e_fmod.c 5.1 93/09/24 */
  /*
   * ====================================================
   * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   *
   * Developed at SunPro, a Sun Microsystems, Inc. business.
   * Permission to use, copy, modify, and distribute this
   * software is freely granted, provided that this notice
   * is preserved.
   * ====================================================
   */
  
  /*
   * __ieee754_fmod(x,y)
   * Return x mod y in exact arithmetic
   * Method: shift and subtract
   */
  
  #ifdef POK_NEEDS_LIBMATH
  
  #include "math_private.h"
  
  static const double one = 1.0, Zero[] = {0.0, -0.0,};
  
  double
  __ieee754_fmod(double x, double y)
  {
  	int32_t n,hx,hy,hz,ix,iy,sx,i;
  	uint32_t lx,ly,lz;
  
  	EXTRACT_WORDS(hx,lx,x);
  	EXTRACT_WORDS(hy,ly,y);
  	sx = hx&0x80000000;		/* sign of x */
  	hx ^=sx;		/* |x| */
  	hy &= 0x7fffffff;	/* |y| */
  
      /* purge off exception values */
  	if((hy|ly)==0||(hx>=0x7ff00000)||	/* y=0,or x not finite */
  	  ((hy|((ly|-ly)>>31))>0x7ff00000))	/* or y is NaN */
  	    return (x*y)/(x*y);
  	if(hx<=hy) {
  	    if((hx<hy)||(lx<ly)) return x;	/* |x|<|y| return x */
  	    if(lx==ly)
  		return Zero[(uint32_t)sx>>31];	/* |x|=|y| return x*0*/
  	}
  
      /* determine ix = ilogb(x) */
  	if(hx<0x00100000) {	/* subnormal x */
  	    if(hx==0) {
  		for (ix = -1043, i=lx; i>0; i<<=1) ix -=1;
  	    } else {
  		for (ix = -1022,i=(hx<<11); i>0; i<<=1) ix -=1;
  	    }
  	} else ix = (hx>>20)-1023;
  
      /* determine iy = ilogb(y) */
  	if(hy<0x00100000) {	/* subnormal y */
  	    if(hy==0) {
  		for (iy = -1043, i=ly; i>0; i<<=1) iy -=1;
  	    } else {
  		for (iy = -1022,i=(hy<<11); i>0; i<<=1) iy -=1;
  	    }
  	} else iy = (hy>>20)-1023;
  
      /* set up {hx,lx}, {hy,ly} and align y to x */
  	if(ix >= -1022)
  	    hx = 0x00100000|(0x000fffff&hx);
  	else {		/* subnormal x, shift x to normal */
  	    n = -1022-ix;
  	    if(n<=31) {
  	        hx = (hx<<n)|(lx>>(32-n));
  	        lx <<= n;
  	    } else {
  		hx = lx<<(n-32);
  		lx = 0;
  	    }
  	}
  	if(iy >= -1022)
  	    hy = 0x00100000|(0x000fffff&hy);
  	else {		/* subnormal y, shift y to normal */
  	    n = -1022-iy;
  	    if(n<=31) {
  	        hy = (hy<<n)|(ly>>(32-n));
  	        ly <<= n;
  	    } else {
  		hy = ly<<(n-32);
  		ly = 0;
  	    }
  	}
  
      /* fix point fmod */
  	n = ix - iy;
  	while(n--) {
  	    hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;
  	    if(hz<0){hx = hx+hx+(lx>>31); lx = lx+lx;}
  	    else {
  	    	if((hz|lz)==0) 		/* return sign(x)*0 */
  		    return Zero[(uint32_t)sx>>31];
  	    	hx = hz+hz+(lz>>31); lx = lz+lz;
  	    }
  	}
  	hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;
  	if(hz>=0) {hx=hz;lx=lz;}
  
      /* convert back to floating value and restore the sign */
  	if((hx|lx)==0) 			/* return sign(x)*0 */
  	    return Zero[(uint32_t)sx>>31];
  	while(hx<0x00100000) {		/* normalize x */
  	    hx = hx+hx+(lx>>31); lx = lx+lx;
  	    iy -= 1;
  	}
  	if(iy>= -1022) {	/* normalize output */
  	    hx = ((hx-0x00100000)|((iy+1023)<<20));
  	    INSERT_WORDS(x,hx|sx,lx);
  	} else {		/* subnormal output */
  	    n = -1022 - iy;
  	    if(n<=20) {
  		lx = (lx>>n)|((uint32_t)hx<<(32-n));
  		hx >>= n;
  	    } else if (n<=31) {
  		lx = (hx<<(32-n))|(lx>>n); hx = sx;
  	    } else {
  		lx = hx>>(n-32); hx = sx;
  	    }
  	    INSERT_WORDS(x,hx|sx,lx);
  	    x *= one;		/* create necessary signal */
  	}
  	return x;		/* exact output */
  }
  #endif
  
  