glibc/sysdeps/loongarch/fpu/e_ilogb.c

40 lines
1.3 KiB
C

/* __ieee754_ilogb(). LoongArch version.
Copyright (C) 2022-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#define NO_MATH_REDIRECT
#include <math.h>
#include <fpu_control.h>
int
__ieee754_ilogb (double x)
{
int x_cond;
asm volatile ("fclass.d \t%0, %1" : "=f" (x_cond) : "f" (x));
if (__glibc_unlikely (x_cond & _FCLASS_ZERO))
return FP_ILOGB0;
else if (__glibc_unlikely (x_cond & ( _FCLASS_NAN | _FCLASS_INF)))
return FP_ILOGBNAN;
else
{
asm volatile ("fabs.d \t%0, %1" : "=f" (x) : "f" (x));
asm volatile ("flogb.d \t%0, %1" : "=f" (x) : "f" (x));
return x;
}
}