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* Rules (tests): Depend on tests-static only if build-static == yes. * misc/Makefile (install-lib): Compile libbsd-compat.a and libg.a only if build-static == yes. 1998-07-29 12:58 Ulrich Drepper <drepper@cygnus.com> * sysdeps/generic/glob.c: Winblowz compatibility stuff. Patch received from Paul D. Smith <psmith@BayNetworks.COM>. 1998-07-29 Andreas Jaeger <aj@arthur.rhein-neckar.de> * sunrpc/clnt_unix.c (__msgwrite)[!SCM_CRED]: Add return statement, fix typo. * sunrpc/svc_unix.c (__msgwrite)[!SCM_CRED]: Likewise. 1998-07-29 Andreas Jaeger <aj@arthur.rhein-neckar.de>
115 lines
2.9 KiB
C
115 lines
2.9 KiB
C
/* Complex square root of double value.
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Copyright (C) 1997, 1998 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Based on an algorithm by Stephen L. Moshier <moshier@world.std.com>.
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Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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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 Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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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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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <complex.h>
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#include <math.h>
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#include "math_private.h"
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__complex__ double
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__csqrt (__complex__ double x)
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{
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__complex__ double res;
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int rcls = fpclassify (__real__ x);
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int icls = fpclassify (__imag__ x);
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if (rcls <= FP_INFINITE || icls <= FP_INFINITE)
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{
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if (icls == FP_INFINITE)
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{
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__real__ res = HUGE_VAL;
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__imag__ res = __imag__ x;
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}
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else if (rcls == FP_INFINITE)
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{
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if (__real__ x < 0.0)
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{
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__real__ res = icls == FP_NAN ? __nan ("") : 0;
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__imag__ res = __copysign (HUGE_VAL, __imag__ x);
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}
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else
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{
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__real__ res = __real__ x;
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__imag__ res = (icls == FP_NAN
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? __nan ("") : __copysign (0.0, __imag__ x));
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}
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}
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else
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{
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__real__ res = __nan ("");
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__imag__ res = __nan ("");
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}
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}
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else
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{
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if (icls == FP_ZERO)
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{
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if (__real__ x < 0.0)
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{
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__real__ res = 0.0;
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__imag__ res = __copysign (__ieee754_sqrt (-__real__ x),
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__imag__ x);
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}
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else
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{
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__real__ res = fabs (__ieee754_sqrt (__real__ x));
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__imag__ res = __copysign (0.0, __imag__ x);
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}
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}
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else if (rcls == FP_ZERO)
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{
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double r = __ieee754_sqrt (0.5 * fabs (__imag__ x));
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__real__ res = __copysign (r, __imag__ x);
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__imag__ res = r;
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}
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else
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{
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double d, r, s;
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d = __ieee754_hypot (__real__ x, __imag__ x);
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/* Use the identity 2 Re res Im res = Im x
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to avoid cancellation error in d +/- Re x. */
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if (__real__ x > 0)
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{
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r = __ieee754_sqrt (0.5 * d + 0.5 * __real__ x);
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s = (0.5 * __imag__ x) / r;
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}
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else
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{
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s = __ieee754_sqrt (0.5 * d - 0.5 * __real__ x);
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r = fabs ((0.5 * __imag__ x) / s);
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}
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__real__ res = r;
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__imag__ res = __copysign (s, __imag__ x);
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}
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}
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return res;
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}
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weak_alias (__csqrt, csqrt)
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#ifdef NO_LONG_DOUBLE
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strong_alias (__csqrt, __csqrtl)
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weak_alias (__csqrt, csqrtl)
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#endif
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