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/* Copyright (C) 1993 Hongjiu Lu
This file is part of the Linux C Library.
The Linux C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The Linux 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
Library General Public License for more details. */
#include <ansidecl.h>
#include <math.h>
#include <errno.h>
static inline double
domain ( double x)
{
/* perror("log"); */
if (x < 0.)
return __infnan( EDOM);
else /* i.e. x== 0. */
return __infnan(-ERANGE);
}
double
DEFUN(log, (x), double x)
{
if (x <= 0.0) return domain (x);
__asm__ __volatile__ ("fldln2\n\t"
"fxch %%st(1)\n\t"
"fyl2x"
:"=t" (x) : "0" (x));
return x;
}
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