Add complex math from musl (#422)

libc/tinymath/csinhf.c

@@ -0,0 +1,127 @@
+/*-*- 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_csinhf.c */
+/*-
+ * Copyright (c) 2005 Bruce D. Evans and Steven G. Kargl
+ * 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 unmodified, 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 ``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 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.
+ */
+/*
+ * Hyperbolic sine of a complex argument z.  See s_csinh.c for details.
+ */
+
+
+static const float huge = 0x1p127;
+
+float complex csinhf(float complex z)
+{
+	float x, y, h;
+	int32_t hx, hy, ix, iy;
+
+	x = crealf(z);
+	y = cimagf(z);
+
+	GET_FLOAT_WORD(hx, x);
+	GET_FLOAT_WORD(hy, y);
+
+	ix = 0x7fffffff & hx;
+	iy = 0x7fffffff & hy;
+
+	if (ix < 0x7f800000 && iy < 0x7f800000) {
+		if (iy == 0)
+			return CMPLXF(sinhf(x), y);
+		if (ix < 0x41100000)    /* small x: normal case */
+			return CMPLXF(sinhf(x) * cosf(y), coshf(x) * sinf(y));
+
+		/* |x| >= 9, so cosh(x) ~= exp(|x|) */
+		if (ix < 0x42b17218) {
+			/* x < 88.7: expf(|x|) won't overflow */
+			h = expf(fabsf(x)) * 0.5f;
+			return CMPLXF(copysignf(h, x) * cosf(y), h * sinf(y));
+		} else if (ix < 0x4340b1e7) {
+			/* x < 192.7: scale to avoid overflow */
+			z = __ldexp_cexpf(CMPLXF(fabsf(x), y), -1);
+			return CMPLXF(crealf(z) * copysignf(1, x), cimagf(z));
+		} else {
+			/* x >= 192.7: the result always overflows */
+			h = huge * x;
+			return CMPLXF(h * cosf(y), h * h * sinf(y));
+		}
+	}
+
+	if (ix == 0 && iy >= 0x7f800000)
+		return CMPLXF(copysignf(0, x * (y - y)), y - y);
+
+	if (iy == 0 && ix >= 0x7f800000) {
+		if ((hx & 0x7fffff) == 0)
+			return CMPLXF(x, y);
+		return CMPLXF(x, copysignf(0, y));
+	}
+
+	if (ix < 0x7f800000 && iy >= 0x7f800000)
+		return CMPLXF(y - y, x * (y - y));
+
+	if (ix >= 0x7f800000 && (hx & 0x7fffff) == 0) {
+		if (iy >= 0x7f800000)
+			return CMPLXF(x * x, x * (y - y));
+		return CMPLXF(x * cosf(y), INFINITY * sinf(y));
+	}
+
+	return CMPLXF((x * x) * (y - y), (x + x) * (y - y));
+}