diff options
-rw-r--r-- | newlib/libm/complex/Makefile.am | 2 | ||||
-rwxr-xr-x | newlib/libm/complex/csqrtl.c | 112 |
2 files changed, 113 insertions, 1 deletions
diff --git a/newlib/libm/complex/Makefile.am b/newlib/libm/complex/Makefile.am index ad5d9a959..c70726e42 100644 --- a/newlib/libm/complex/Makefile.am +++ b/newlib/libm/complex/Makefile.am @@ -11,7 +11,7 @@ src = cabs.c cacos.c cacosh.c carg.c casin.c casinh.c \ csin.c csinh.c csqrt.c ctan.c ctanh.c lsrc = cabsl.c creall.c cimagl.c ccoshl.c cacoshl.c \ - clogl.c + clogl.c csqrtl.c fsrc = cabsf.c casinf.c ccosf.c cimagf.c cprojf.c \ csqrtf.c cacosf.c casinhf.c ccoshf.c clogf.c clog10f.c \ diff --git a/newlib/libm/complex/csqrtl.c b/newlib/libm/complex/csqrtl.c new file mode 100755 index 000000000..c10a1264a --- /dev/null +++ b/newlib/libm/complex/csqrtl.c @@ -0,0 +1,112 @@ +/*- + * Copyright (c) 2007-2008 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. + */ + +#include <sys/cdefs.h> +#if 0 +__FBSDID("$FreeBSD: head/lib/msun/src/s_csqrtl.c 181402 2008-08-08 00:15:16Z das $"); +#else +__RCSID("$NetBSD: csqrtl.c,v 1.2 2014/10/11 00:43:51 christos Exp $"); +#endif + +#include <complex.h> +#include <float.h> +#include <math.h> +#include <stdbool.h> +/* + * 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 >= LDBL_MAX / (1 + sqrt(2)). */ +#define THRESH (LDBL_MAX / 2.414213562373095048801688724209698L) + +#define cpackl(r, i) ((r) + (i) * I) + +long double complex +csqrtl(long double complex z) +{ + long double complex result; + long double a, b; + long double t; + bool scale; + + a = creall(z); + b = cimagl(z); + + /* Handle special cases. */ + if (z == 0.0L) + return (cpackl(0.0L, b)); + if (isinf(b)) + return (cpackl(INFINITY, b)); + if (isnan(a)) { + t = (b - b) / (b - b); /* raise invalid if b is not a NaN */ + return (cpackl(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 (cpackl(fabsl(b - b), copysignl(a, b))); + else + return (cpackl(a, copysignl(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 (fabsl(a) >= THRESH || fabsl(b) >= THRESH) { + a *= 0.25L; + b *= 0.25L; + scale = true; + } else { + scale = false; + } + + /* Algorithm 312, CACM vol 10, Oct 1967. */ + if (a >= 0L) { + t = sqrtl((a + hypotl(a, b)) * 0.5L); + result = cpackl(t, b / (2.0L * t)); + } else { + t = sqrtl((-a + hypotl(a, b)) * 0.5L); + result = cpackl(fabsl(b) / (2.0L * t), copysignl(t, b)); + } + + /* Rescale. */ + if (scale) + return (result * 2.0L); + else + return (result); +} |