Add complex math from musl (#422)

2025-05-23 05:42:29 +00:00 · 2022-06-24 07:26:10 +05:30 · 2022-06-24 07:26:10 +05:30 · 5d837c4e7c
commit 5d837c4e7c
parent 1bce1ca2e0
52 changed files with 3667 additions and 1 deletions
--- a/libc/tinymath/cexp.c
+++ b/libc/tinymath/cexp.c
@ -0,0 +1,120 @@
+/*-*- 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/complex.h"
+#include "libc/math.h"
+#include "libc/tinymath/complex.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_cexp.c */
+/*-
+ * Copyright (c) 2011 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.
+ */
+
+
+static const uint32_t
+exp_ovfl  = 0x40862e42,  /* high bits of MAX_EXP * ln2 ~= 710 */
+cexp_ovfl = 0x4096b8e4;  /* (MAX_EXP - MIN_DENORM_EXP) * ln2 */
+
+double complex cexp(double complex z)
+{
+	double x, y, exp_x;
+	uint32_t hx, hy, lx, ly;
+
+	x = creal(z);
+	y = cimag(z);
+
+	EXTRACT_WORDS(hy, ly, y);
+	hy &= 0x7fffffff;
+
+	/* cexp(x + I 0) = exp(x) + I 0 */
+	if ((hy | ly) == 0)
+		return CMPLX(exp(x), y);
+	EXTRACT_WORDS(hx, lx, x);
+	/* cexp(0 + I y) = cos(y) + I sin(y) */
+	if (((hx & 0x7fffffff) | lx) == 0)
+		return CMPLX(cos(y), sin(y));
+
+	if (hy >= 0x7ff00000) {
+		if (lx != 0 || (hx & 0x7fffffff) != 0x7ff00000) {
+			/* cexp(finite|NaN +- I Inf|NaN) = NaN + I NaN */
+			return CMPLX(y - y, y - y);
+		} else if (hx & 0x80000000) {
+			/* cexp(-Inf +- I Inf|NaN) = 0 + I 0 */
+			return CMPLX(0.0, 0.0);
+		} else {
+			/* cexp(+Inf +- I Inf|NaN) = Inf + I NaN */
+			return CMPLX(x, y - y);
+		}
+	}
+
+	if (hx >= exp_ovfl && hx <= cexp_ovfl) {
+		/*
+		 * x is between 709.7 and 1454.3, so we must scale to avoid
+		 * overflow in exp(x).
+		 */
+		return __ldexp_cexp(z, 0);
+	} else {
+		/*
+		 * Cases covered here:
+		 *  -  x < exp_ovfl and exp(x) won't overflow (common case)
+		 *  -  x > cexp_ovfl, so exp(x) * s overflows for all s > 0
+		 *  -  x = +-Inf (generated by exp())
+		 *  -  x = NaN (spurious inexact exception from y)
+		 */
+		exp_x = exp(x);
+		return CMPLX(exp_x * cos(y), exp_x * sin(y));
+	}
+}