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kernel/linux-rt-4.4.41/arch/mips/math-emu/sp_fint.c 1.51 KB
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  /* IEEE754 floating point arithmetic
   * single precision
   */
  /*
   * MIPS floating point support
   * Copyright (C) 1994-2000 Algorithmics Ltd.
   *
   *  This program is free software; you can distribute it and/or modify it
   *  under the terms of the GNU General Public License (Version 2) as
   *  published by the Free Software Foundation.
   *
   *  This program is distributed in the hope it will be useful, but WITHOUT
   *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   *  for more details.
   *
   *  You should have received a copy of the GNU General Public License along
   *  with this program; if not, write to the Free Software Foundation, Inc.,
   *  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA.
   */
  
  #include "ieee754sp.h"
  
  union ieee754sp ieee754sp_fint(int x)
  {
  	unsigned xm;
  	int xe;
  	int xs;
  
  	ieee754_clearcx();
  
  	if (x == 0)
  		return ieee754sp_zero(0);
  	if (x == 1 || x == -1)
  		return ieee754sp_one(x < 0);
  	if (x == 10 || x == -10)
  		return ieee754sp_ten(x < 0);
  
  	xs = (x < 0);
  	if (xs) {
  		if (x == (1 << 31))
  			xm = ((unsigned) 1 << 31);	/* max neg can't be safely negated */
  		else
  			xm = -x;
  	} else {
  		xm = x;
  	}
  	xe = SP_FBITS + 3;
  
  	if (xm >> (SP_FBITS + 1 + 3)) {
  		/* shunt out overflow bits
  		 */
  		while (xm >> (SP_FBITS + 1 + 3)) {
  			SPXSRSX1();
  		}
  	} else {
  		/* normalize in grs extended single precision
  		 */
  		while ((xm >> (SP_FBITS + 3)) == 0) {
  			xm <<= 1;
  			xe--;
  		}
  	}
  	return ieee754sp_format(xs, xe, xm);
  }