Add complex square root (#394)

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Steve Phillips 2022-04-27 21:19:48 -07:00 committed by GitHub
parent cc0d1ec076
commit 92ebef16ee
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3 changed files with 288 additions and 0 deletions

133
libc/tinymath/complex.h Normal file
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#ifndef _COMPLEX_H
#define _COMPLEX_H
#ifdef __cplusplus
extern "C" {
#endif
#define complex _Complex
#ifdef __GNUC__
#define _Complex_I (__extension__ (0.0f+1.0fi))
#else
#define _Complex_I (0.0f+1.0fi)
#endif
#define I _Complex_I
double complex cacos(double complex);
float complex cacosf(float complex);
long double complex cacosl(long double complex);
double complex casin(double complex);
float complex casinf(float complex);
long double complex casinl(long double complex);
double complex catan(double complex);
float complex catanf(float complex);
long double complex catanl(long double complex);
double complex ccos(double complex);
float complex ccosf(float complex);
long double complex ccosl(long double complex);
double complex csin(double complex);
float complex csinf(float complex);
long double complex csinl(long double complex);
double complex ctan(double complex);
float complex ctanf(float complex);
long double complex ctanl(long double complex);
double complex cacosh(double complex);
float complex cacoshf(float complex);
long double complex cacoshl(long double complex);
double complex casinh(double complex);
float complex casinhf(float complex);
long double complex casinhl(long double complex);
double complex catanh(double complex);
float complex catanhf(float complex);
long double complex catanhl(long double complex);
double complex ccosh(double complex);
float complex ccoshf(float complex);
long double complex ccoshl(long double complex);
double complex csinh(double complex);
float complex csinhf(float complex);
long double complex csinhl(long double complex);
double complex ctanh(double complex);
float complex ctanhf(float complex);
long double complex ctanhl(long double complex);
double complex cexp(double complex);
float complex cexpf(float complex);
long double complex cexpl(long double complex);
double complex clog(double complex);
float complex clogf(float complex);
long double complex clogl(long double complex);
double cabs(double complex);
float cabsf(float complex);
long double cabsl(long double complex);
double complex cpow(double complex, double complex);
float complex cpowf(float complex, float complex);
long double complex cpowl(long double complex, long double complex);
double complex csqrt(double complex);
float complex csqrtf(float complex);
long double complex csqrtl(long double complex);
double carg(double complex);
float cargf(float complex);
long double cargl(long double complex);
double cimag(double complex);
float cimagf(float complex);
long double cimagl(long double complex);
double complex conj(double complex);
float complex conjf(float complex);
long double complex conjl(long double complex);
double complex cproj(double complex);
float complex cprojf(float complex);
long double complex cprojl(long double complex);
double creal(double complex);
float crealf(float complex);
long double creall(long double complex);
#ifndef __cplusplus
#define __CIMAG(x, t) \
(+(union { _Complex t __z; t __xy[2]; }){(_Complex t)(x)}.__xy[1])
#define creal(x) ((double)(x))
#define crealf(x) ((float)(x))
#define creall(x) ((long double)(x))
#define cimag(x) __CIMAG(x, double)
#define cimagf(x) __CIMAG(x, float)
#define cimagl(x) __CIMAG(x, long double)
#endif
#if __STDC_VERSION__ >= 201112L
#if defined(_Imaginary_I)
#define __CMPLX(x, y, t) ((t)(x) + _Imaginary_I*(t)(y))
#elif defined(__clang__)
#define __CMPLX(x, y, t) (+(_Complex t){ (t)(x), (t)(y) })
#else
#define __CMPLX(x, y, t) (__builtin_complex((t)(x), (t)(y)))
#endif
#define CMPLX(x, y) __CMPLX(x, y, double)
#define CMPLXF(x, y) __CMPLX(x, y, float)
#define CMPLXL(x, y) __CMPLX(x, y, long double)
#endif
#ifdef __cplusplus
}
#endif
#endif

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#ifndef _COMPLEX_IMPL_H
#define _COMPLEX_IMPL_H
#include <libc/tinymath/complex.h>
#include "libc/math.h"
#undef __CMPLX
#undef CMPLX
#undef CMPLXF
#undef CMPLXL
#define __CMPLX(x, y, t) \
((union { _Complex t __z; t __xy[2]; }){.__xy = {(x),(y)}}.__z)
#define CMPLX(x, y) __CMPLX(x, y, double)
#define CMPLXF(x, y) __CMPLX(x, y, float)
#define CMPLXL(x, y) __CMPLX(x, y, long double)
hidden double complex __ldexp_cexp(double complex,int);
hidden float complex __ldexp_cexpf(float complex,int);
#endif

133
libc/tinymath/csqrt.c Normal file
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/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
vi: set et ft=c ts=8 tw=8 fenc=utf-8 :vi
Musl Libc
Copyright © 2005-2014 Rich Felker, et al.
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "libc/tinymath/complex_impl.internal.h"
asm(".ident\t\"\\n\\n\
Musl libc (MIT License)\\n\
Copyright 2005-2014 Rich Felker, et. al.\"");
asm(".include \"libc/disclaimer.inc\"");
/* clang-format off */
/* origin: FreeBSD /usr/src/lib/msun/src/s_csqrt.c */
/*-
* Copyright (c) 2007 David Schultz <das@FreeBSD.ORG>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* gcc doesn't implement complex multiplication or division correctly,
* so we need to handle infinities specially. We turn on this pragma to
* notify conforming c99 compilers that the fast-but-incorrect code that
* gcc generates is acceptable, since the special cases have already been
* handled.
*/
#pragma STDC CX_LIMITED_RANGE ON
/* We risk spurious overflow for components >= DBL_MAX / (1 + sqrt(2)). */
#define THRESH 0x1.a827999fcef32p+1022
double complex csqrt(double complex z)
{
double complex result;
double a, b;
double t;
int scale;
a = creal(z);
b = cimag(z);
/* Handle special cases. */
if (z == 0)
return CMPLX(0, b);
if (isinf(b))
return CMPLX(INFINITY, b);
if (isnan(a)) {
t = (b - b) / (b - b); /* raise invalid if b is not a NaN */
return CMPLX(a, t); /* return NaN + NaN i */
}
if (isinf(a)) {
/*
* csqrt(inf + NaN i) = inf + NaN i
* csqrt(inf + y i) = inf + 0 i
* csqrt(-inf + NaN i) = NaN +- inf i
* csqrt(-inf + y i) = 0 + inf i
*/
if (signbit(a))
return CMPLX(fabs(b - b), copysign(a, b));
else
return CMPLX(a, copysign(b - b, b));
}
/*
* The remaining special case (b is NaN) is handled just fine by
* the normal code path below.
*/
/* Scale to avoid overflow. */
if (fabs(a) >= THRESH || fabs(b) >= THRESH) {
a *= 0.25;
b *= 0.25;
scale = 1;
} else {
scale = 0;
}
/* Algorithm 312, CACM vol 10, Oct 1967. */
if (a >= 0) {
t = sqrt((a + hypot(a, b)) * 0.5);
result = CMPLX(t, b / (2 * t));
} else {
t = sqrt((-a + hypot(a, b)) * 0.5);
result = CMPLX(fabs(b) / (2 * t), copysign(t, b));
}
/* Rescale. */
if (scale)
result *= 2;
return result;
}