1  /*
       2   * Copyright (C) 2001-2023 Free Software Foundation, Inc.
       3   * Contributed by David S. Miller (davem@redhat.com)
       4   *
       5   * This file is free software; you can redistribute it and/or modify it
       6   * under the terms of the GNU General Public License as published by the
       7   * Free Software Foundation; either version 3, or (at your option) any
       8   * later version.
       9   * 
      10   * This file is distributed in the hope that it will be useful, but
      11   * WITHOUT ANY WARRANTY; without even the implied warranty of
      12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13   * General Public License for more details.
      14   * 
      15   * Under Section 7 of GPL version 3, you are granted additional
      16   * permissions described in the GCC Runtime Library Exception, version
      17   * 3.1, as published by the Free Software Foundation.
      18   *
      19   * You should have received a copy of the GNU General Public License and
      20   * a copy of the GCC Runtime Library Exception along with this program;
      21   * see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      22   * <http://www.gnu.org/licenses/>.
      23   */
      24  
      25  #define FPRS_NS		(1 << 22)	/* Non-Standard fpu results */
      26  
      27  static void __attribute__((constructor))
      28  set_fast_math (void)
      29  {
      30    unsigned int fsr;
      31  
      32    /* This works for the 64-bit case because, even if 32-bit ld/st of
      33       the fsr register modified the upper 32-bit, the only thing up there
      34       are the 3 other condition codes which are "do not care" at the time
      35       that this runs.  */
      36  
      37    __asm__("st %%fsr, %0"
      38  	  : "=m" (fsr));
      39  
      40    fsr |= FPRS_NS;
      41  
      42    __asm__("ld %0, %%fsr"
      43  	  : : "m" (fsr));
      44  }