Add a "fork" of musl as //fusl.

fusl/src/complex/ctanhf.c

Index: fusl/src/complex/ctanhf.c
diff --git a/third_party/libevent/epoll_sub.c b/fusl/src/complex/ctanhf.c
similarity index 54%
copy from third_party/libevent/epoll_sub.c
copy to fusl/src/complex/ctanhf.c
index 431970c73a6dbe5ff900ac9962f3d3dcc8ddf16f..72b76da075cf83f26a3ea7297af2d0e5e052b039 100644
--- a/third_party/libevent/epoll_sub.c
+++ b/fusl/src/complex/ctanhf.c
@@ -1,17 +1,17 @@
-/*
- * Copyright 2003 Niels Provos <provos@citi.umich.edu>
+/* origin: FreeBSD /usr/src/lib/msun/src/s_ctanhf.c */
+/*-
+ * Copyright (c) 2011 David Schultz
  * 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.
+ *    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.
- * 3. The name of the author may not be used to endorse or promote products
- *    derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
@@ -24,29 +24,43 @@
  * (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 <stdint.h>
+/*
+ * Hyperbolic tangent of a complex argument z.  See s_ctanh.c for details.
+ */
 
-#include <sys/param.h>
-#include <sys/types.h>
-#include <sys/syscall.h>
-#include <sys/epoll.h>
-#include <unistd.h>
+#include "libm.h"
 
-int
-epoll_create(int size)
+float complex ctanhf(float complex z)
 {
-	return (syscall(__NR_epoll_create, size));
-}
+	float x, y;
+	float t, beta, s, rho, denom;
+	uint32_t hx, ix;
 
-int
-epoll_ctl(int epfd, int op, int fd, struct epoll_event *event)
-{
+	x = crealf(z);
+	y = cimagf(z);
 
-	return (syscall(__NR_epoll_ctl, epfd, op, fd, event));
-}
+	GET_FLOAT_WORD(hx, x);
+	ix = hx & 0x7fffffff;
 
-int
-epoll_wait(int epfd, struct epoll_event *events, int maxevents, int timeout)
-{
-	return (syscall(__NR_epoll_wait, epfd, events, maxevents, timeout));
+	if (ix >= 0x7f800000) {
+		if (ix & 0x7fffff)
+			return CMPLXF(x, (y == 0 ? y : x * y));
+		SET_FLOAT_WORD(x, hx - 0x40000000);
+		return CMPLXF(x, copysignf(0, isinf(y) ? y : sinf(y) * cosf(y)));
+	}
+
+	if (!isfinite(y))
+		return CMPLXF(ix ? y - y : x, y - y);
+
+	if (ix >= 0x41300000) { /* x >= 11 */
+		float exp_mx = expf(-fabsf(x));
+		return CMPLXF(copysignf(1, x), 4 * sinf(y) * cosf(y) * exp_mx * exp_mx);
+	}
+
+	t = tanf(y);
+	beta = 1.0 + t * t;
+	s = sinhf(x);
+	rho = sqrtf(1 + s * s);
+	denom = 1 + beta * s * s;
+	return CMPLXF((beta * rho * s) / denom, t / denom);
 }