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Implement csqrtl().
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svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=177761
@ -60,6 +60,8 @@ float crealf(float complex);
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long double creall(long double complex);
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double complex csqrt(double complex);
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float complex csqrtf(float complex);
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long double complex
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csqrtl(long double complex);
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__END_DECLS
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@ -80,7 +80,7 @@ COMMON_SRCS+= s_copysignl.c s_fabsl.c s_llrintl.c s_lrintl.c s_modfl.c
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.if ${LDBL_PREC} != 53
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# If long double != double use these; otherwise, we alias the double versions.
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COMMON_SRCS+= e_hypotl.c e_sqrtl.c k_cosl.c k_sinl.c k_tanl.c \
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s_ceill.c s_cosl.c s_exp2l.c s_floorl.c s_fmal.c \
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s_ceill.c s_cosl.c s_csqrtl.c s_exp2l.c s_floorl.c s_fmal.c \
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s_frexpl.c s_logbl.c s_nanl.c s_nextafterl.c s_nexttoward.c \
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s_rintl.c s_scalbnl.c s_sinl.c s_tanl.c s_truncl.c w_cabsl.c
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.endif
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@ -127,7 +127,7 @@ MLINKS+=cimag.3 cimagf.3 cimag.3 cimagl.3 \
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MLINKS+=copysign.3 copysignf.3 copysign.3 copysignl.3
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MLINKS+=cos.3 cosf.3 cos.3 cosl.3
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MLINKS+=cosh.3 coshf.3
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MLINKS+=csqrt.3 csqrtf.3
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MLINKS+=csqrt.3 csqrtf.3 csqrt.3 csqrtl.3
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MLINKS+=erf.3 erfc.3 erf.3 erff.3 erf.3 erfcf.3
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MLINKS+=exp.3 expm1.3 exp.3 expm1f.3 exp.3 pow.3 exp.3 powf.3 \
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exp.3 exp2.3 exp.3 exp2f.3 exp.3 exp2l.3 exp.3 expf.3
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@ -205,4 +205,5 @@ FBSD_1.1 {
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sqrtl;
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hypotl;
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cabsl;
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csqrtl;
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};
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@ -1,4 +1,4 @@
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.\" Copyright (c) 2007 David Schultz <das@FreeBSD.org>
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.\" Copyright (c) 2007-2008 David Schultz <das@FreeBSD.org>
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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@ -24,12 +24,13 @@
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.\"
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.\" $FreeBSD$
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.\"
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.Dd December 14, 2007
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.Dd March 30, 2008
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.Dt CSQRT 3
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.Os
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.Sh NAME
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.Nm csqrt ,
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.Nm csqrtf
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.Nm csqrtf ,
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.Nm csqrtl
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.Nd complex square root functions
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.Sh LIBRARY
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.Lb libm
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@ -39,18 +40,22 @@
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.Fn csqrt "double complex z"
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.Ft float complex
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.Fn csqrtf "float complex z"
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.Ft long double complex
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.Fn csqrtl "long double complex z"
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.Sh DESCRIPTION
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The
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.Fn csqrt
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.Fn csqrt ,
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.Fn csqrtf ,
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and
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.Fn csqrtf
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.Fn csqrtl
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functions compute the square root of
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.Fa z
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in the complex plane, with a branch cut along the negative real axis.
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In other words,
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.Fn csqrt
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.Fn csqrt ,
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.Fn csqrtf ,
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and
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.Fn csqrtf
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.Fn csqrtl
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always return the square root whose real part is non-negative.
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.Sh RETURN VALUES
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These functions return the requested square root.
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@ -83,12 +88,15 @@ an \*(Na is generated, an invalid exception will be thrown.
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.Xr math 3 ,
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.Sh STANDARDS
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The
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.Fn csqrt
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.Fn csqrt ,
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.Fn csqrtf ,
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and
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.Fn csqrtf
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.Fn csqrtl
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functions conform to
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.St -isoC-99 .
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.Sh BUGS
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For
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.Fn csqrt ,
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inexact results are not correctly rounded in general.
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.Fn csqrt
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and
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.Fn csqrtl ,
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inexact results are not always correctly rounded.
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@ -28,6 +28,7 @@
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__FBSDID("$FreeBSD$");
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#include <complex.h>
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#include <float.h>
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#include <math.h>
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#include "math_private.h"
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@ -105,3 +106,7 @@ csqrt(double complex z)
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else
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return (result);
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}
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#if LDBL_MANT_DIG == 53
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__weak_reference(csqrt, csqrtl);
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#endif
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108
lib/msun/src/s_csqrtl.c
Normal file
108
lib/msun/src/s_csqrtl.c
Normal file
@ -0,0 +1,108 @@
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/*-
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* Copyright (c) 2007-2008 David Schultz <das@FreeBSD.ORG>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <complex.h>
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#include <float.h>
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#include <math.h>
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#include "math_private.h"
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/*
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* gcc doesn't implement complex multiplication or division correctly,
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* so we need to handle infinities specially. We turn on this pragma to
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* notify conforming c99 compilers that the fast-but-incorrect code that
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* gcc generates is acceptable, since the special cases have already been
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* handled.
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*/
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#pragma STDC CX_LIMITED_RANGE on
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/* We risk spurious overflow for components >= LDBL_MAX / (1 + sqrt(2)). */
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#define THRESH (LDBL_MAX / 2.414213562373095048801688724209698L)
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long double complex
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csqrtl(long double complex z)
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{
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long double complex result;
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long double a, b;
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long double t;
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int scale;
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a = creall(z);
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b = cimagl(z);
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/* Handle special cases. */
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if (z == 0)
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return (cpackl(0, b));
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if (isinf(b))
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return (cpackl(INFINITY, b));
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if (isnan(a)) {
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t = (b - b) / (b - b); /* raise invalid if b is not a NaN */
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return (cpackl(a, t)); /* return NaN + NaN i */
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}
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if (isinf(a)) {
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/*
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* csqrt(inf + NaN i) = inf + NaN i
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* csqrt(inf + y i) = inf + 0 i
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* csqrt(-inf + NaN i) = NaN +- inf i
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* csqrt(-inf + y i) = 0 + inf i
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*/
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if (signbit(a))
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return (cpackl(fabsl(b - b), copysignl(a, b)));
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else
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return (cpackl(a, copysignl(b - b, b)));
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}
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/*
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* The remaining special case (b is NaN) is handled just fine by
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* the normal code path below.
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*/
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/* Scale to avoid overflow. */
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if (fabsl(a) >= THRESH || fabsl(b) >= THRESH) {
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a *= 0.25;
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b *= 0.25;
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scale = 1;
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} else {
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scale = 0;
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}
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/* Algorithm 312, CACM vol 10, Oct 1967. */
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if (a >= 0) {
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t = sqrtl((a + hypotl(a, b)) * 0.5);
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result = cpackl(t, b / (2 * t));
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} else {
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t = sqrtl((-a + hypotl(a, b)) * 0.5);
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result = cpackl(fabsl(b) / (2 * t), copysignl(t, b));
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}
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/* Rescale. */
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if (scale)
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return (result * 2);
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else
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return (result);
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}
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