src/math/sinhf.c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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;
}