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kernel/linux-rt-4.4.41/arch/mips/math-emu/dp_fint.c 1.4 KB
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  /* IEEE754 floating point arithmetic
   * double precision: common utilities
   */
  /*
   * 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 "ieee754dp.h"
  
  union ieee754dp ieee754dp_fint(int x)
  {
  	u64 xm;
  	int xe;
  	int xs;
  
  	ieee754_clearcx();
  
  	if (x == 0)
  		return ieee754dp_zero(0);
  	if (x == 1 || x == -1)
  		return ieee754dp_one(x < 0);
  	if (x == 10 || x == -10)
  		return ieee754dp_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;
  	}
  
  	/* normalize - result can never be inexact or overflow */
  	xe = DP_FBITS;
  	while ((xm >> DP_FBITS) == 0) {
  		xm <<= 1;
  		xe--;
  	}
  	return builddp(xs, xe + DP_EBIAS, xm & ~DP_HIDDEN_BIT);
  }