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

fusl/src/math/sinhl.c

Index: fusl/src/math/sinhl.c
diff --git a/fusl/src/math/sinhl.c b/fusl/src/math/sinhl.c
new file mode 100644
index 0000000000000000000000000000000000000000..b305d4d2f3e9c5965bdbf4ddb445adef0168fd85
--- /dev/null
+++ b/fusl/src/math/sinhl.c
@@ -0,0 +1,43 @@
+#include "libm.h"
+
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+long double sinhl(long double x)
+{
+	return sinh(x);
+}
+#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
+long double sinhl(long double x)
+{
+	union ldshape u = {x};
+	unsigned ex = u.i.se & 0x7fff;
+	long double h, t, absx;
+
+	h = 0.5;
+	if (u.i.se & 0x8000)
+		h = -h;
+	/* |x| */
+	u.i.se = ex;
+	absx = u.f;
+
+	/* |x| < log(LDBL_MAX) */
+	if (ex < 0x3fff+13 || (ex == 0x3fff+13 && u.i.m>>32 < 0xb17217f7)) {
+		t = expm1l(absx);
+		if (ex < 0x3fff) {
+			if (ex < 0x3fff-32)
+				return x;
+			return h*(2*t - t*t/(1+t));
+		}
+		return h*(t + t/(t+1));
+	}
+
+	/* |x| > log(LDBL_MAX) or nan */
+	t = expl(0.5*absx);
+	return h*t*t;
+}
+#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
+// TODO: broken implementation to make things compile
+long double sinhl(long double x)
+{
+	return sinh(x);
+}
+#endif