static inline floating_t fast_sqrt()

in pachi_py/pachi/uct/policy/ucb1amaf.c [62:102]

• 41 lines of code
• 2 McCabe index (conditional complexity)

static inline floating_t fast_sqrt(unsigned int x)
{
	static const floating_t table[] = {
		0, 1, 1.41421356237309504880, 1.73205080756887729352,
		2.00000000000000000000, 2.23606797749978969640,
		2.44948974278317809819, 2.64575131106459059050,
		2.82842712474619009760, 3.00000000000000000000,
		3.16227766016837933199, 3.31662479035539984911,
		3.46410161513775458705, 3.60555127546398929311,
		3.74165738677394138558, 3.87298334620741688517,
		4.00000000000000000000, 4.12310562561766054982,
		4.24264068711928514640, 4.35889894354067355223,
		4.47213595499957939281, 4.58257569495584000658,
		4.69041575982342955456, 4.79583152331271954159,
		4.89897948556635619639, 5.00000000000000000000,
		5.09901951359278483002, 5.19615242270663188058,
		5.29150262212918118100, 5.38516480713450403125,
		5.47722557505166113456, 5.56776436283002192211,
		5.65685424949238019520, 5.74456264653802865985,
		5.83095189484530047087, 5.91607978309961604256,
		6.00000000000000000000, 6.08276253029821968899,
		6.16441400296897645025, 6.24499799839839820584,
		6.32455532033675866399, 6.40312423743284868648,
		6.48074069840786023096, 6.55743852430200065234,
		6.63324958071079969822, 6.70820393249936908922,
		6.78232998312526813906, 6.85565460040104412493,
		6.92820323027550917410, 7.00000000000000000000,
		7.07106781186547524400, 7.14142842854284999799,
		7.21110255092797858623, 7.28010988928051827109,
		7.34846922834953429459, 7.41619848709566294871,
		7.48331477354788277116, 7.54983443527074969723,
		7.61577310586390828566, 7.68114574786860817576,
		7.74596669241483377035, 7.81024967590665439412,
		7.87400787401181101968, 7.93725393319377177150,
	};
	if (x < sizeof(table) / sizeof(*table)) {
		return table[x];
	} else {
		return sqrt(x);
	}
}