sysdeps/loongarch/fpu/e_ilogbf.c

   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 }