clz emulation

clz.c

static inline int clz(uint32_t input)
{
	const uint8_t clz_lut[16] = { 4, 3, 2, 2, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0 };

	unsigned c = 0;
	if (input & 0xFFFF0000)
		input >>= 16;
	else
		c = 16;

	if (input & 0xFF00)
		input >>= 8;
	else
		c += 8;

	if (input & 0xF0)
		input >>= 4;
	else
		c += 4;

	return clz_lut[input] + c;
}