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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>
double
DEFUN(asin, (x), double x)
{
double y;
if (x <= -1.0 ) {
if (x == -1.0) {
return -M_PI_2;
}
return __infnan( EDOM);
}
if (x >= 1.0 ) {
if (x == 1.0) {
return M_PI_2;
}
return __infnan( EDOM);
}
y = sqrt (1.0 - x * x);
__asm__ __volatile__ ("fpatan"
:"=t" (y) : "0" (y), "u" (x));
return y;
}
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