1  /* __ieee754_ilogbf().  LoongArch version.
       2     Copyright (C) 2022-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #define NO_MATH_REDIRECT
      20  #include <math.h>
      21  #include <fpu_control.h>
      22  
      23  int
      24  __ieee754_ilogbf (float x)
      25  {
      26    int x_cond;
      27    asm volatile ("fclass.s \t%0, %1" : "=f" (x_cond) : "f" (x));
      28  
      29    if (__glibc_unlikely (x_cond & _FCLASS_ZERO))
      30        return FP_ILOGB0;
      31    else if (__glibc_unlikely (x_cond & ( _FCLASS_NAN | _FCLASS_INF)))
      32        return FP_ILOGBNAN;
      33    else
      34      {
      35        asm volatile ("fabs.s \t%0, %1" : "=f" (x) : "f" (x));
      36        asm volatile ("flogb.s \t%0, %1" : "=f" (x) : "f" (x));
      37        return x;
      38      }
      39  }