usr: libc: Add math.h + musl math impl portexpt

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/lib/libc/src/musl-math/sinhf.c b/lib/libc/src/musl-math/sinhf.c
new file mode 100644
index 0000000..6ad19ea
--- /dev/null
+++ b/lib/libc/src/musl-math/sinhf.c
@@ -0,0 +1,31 @@
+#include "libm.h"
+
+float sinhf(float x)
+{
+	union {float f; uint32_t i;} u = {.f = x};
+	uint32_t w;
+	float t, h, absx;
+
+	h = 0.5;
+	if (u.i >> 31)
+		h = -h;
+	/* |x| */
+	u.i &= 0x7fffffff;
+	absx = u.f;
+	w = u.i;
+
+	/* |x| < log(FLT_MAX) */
+	if (w < 0x42b17217) {
+		t = expm1f(absx);
+		if (w < 0x3f800000) {
+			if (w < 0x3f800000 - (12<<23))
+				return x;
+			return h*(2*t - t*t/(t+1));
+		}
+		return h*(t + t/(t+1));
+	}
+
+	/* |x| > logf(FLT_MAX) or nan */
+	t = 2*h*__expo2f(absx);
+	return t;
+}