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105 lines
2.5 KiB
C
105 lines
2.5 KiB
C
/* Copyright (C) 1997, 1999 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <math.h>
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#include "math_private.h"
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#include "mathimpl.h"
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#ifndef SUFF
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#define SUFF
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#endif
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#ifndef float_type
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#define float_type double
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#endif
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#define CONCATX(a,b) __CONCAT(a,b)
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#define s(name) CONCATX(name,SUFF)
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#define m81(func) __m81_u(s(func))
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float_type
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s(__ieee754_atan2) (float_type y, float_type x)
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{
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float_type pi, pi_2, z;
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unsigned long y_cond, x_cond;
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__asm ("fmovecr%.x %#0, %0" : "=f" (pi));
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__asm ("fscale%.w %#-1, %0" : "=f" (pi_2) : "0" (pi));
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y_cond = __m81_test (y);
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x_cond = __m81_test (x);
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if ((x_cond | y_cond) & __M81_COND_NAN)
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z = x + y;
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else if (y_cond & __M81_COND_ZERO)
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{
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if (x_cond & __M81_COND_NEG)
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z = y_cond & __M81_COND_NEG ? -pi : pi;
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else
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z = y;
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}
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else if (x_cond & __M81_COND_INF)
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{
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if (y_cond & __M81_COND_INF)
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{
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float_type pi_4;
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__asm ("fscale%.w %#-2, %0" : "=f" (pi_4) : "0" (pi));
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z = x_cond & __M81_COND_NEG ? 3 * pi_4 : pi_4;
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}
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else
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z = x_cond & __M81_COND_NEG ? pi : 0;
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if (y_cond & __M81_COND_NEG)
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z = -z;
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}
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else if (y_cond & __M81_COND_INF)
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z = y_cond & __M81_COND_NEG ? -pi_2 : pi_2;
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else if (x_cond & __M81_COND_NEG)
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{
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if (y_cond & __M81_COND_NEG)
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{
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if (-x > -y)
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z = -pi + m81(__atan) (y / x);
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else
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z = -pi_2 - m81(__atan) (x / y);
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}
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else
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{
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if (-x > y)
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z = pi + m81(__atan) (y / x);
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else
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z = pi_2 - m81(__atan) (x / y);
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}
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}
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else
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{
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if (y_cond & __M81_COND_NEG)
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{
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if (x > -y)
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z = m81(__atan) (y / x);
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else
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z = -pi_2 - m81(__atan) (x / y);
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}
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else
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{
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if (x > y)
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z = m81(__atan) (y / x);
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else
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z = pi_2 - m81(__atan) (x / y);
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}
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}
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return z;
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}
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