CS153/hw5/hw4programs/float_multiply.oat

global float_len = 2;
int[] determine_shift(int[] float)
{
	var dec = float[1];
	var count = 0;
	while(dec > 0)
	{
		var temp = float[0];
		float[0] = temp << 1;
		dec = dec >>> 1;
		count = count + 1;
	}
	var list = new int[2];
	list[0] = float[0] + float[1];
	list[1] = count;
	return list;
}

int[] multiply_floats(int[] f1, int[] f2)
{
	var f1_shifted = determine_shift(f1);
	var f2_shifted = determine_shift(f2);
	var product = f1_shifted[0] * f2_shifted[0];
	var num_left_shifts = f1_shifted[1] + f2_shifted[1];
	var remainder = 0;
	for(var i = 0; i < num_left_shifts; i=i+1;)
	{
		var lsb = product [&] 1;
		var shifted_lsb = lsb << i;
		product = product >>> 1;
		remainder = remainder + shifted_lsb;
	}
	var ans = new int[2];
	ans[0] = product;
	ans[1] = remainder;
	return ans;
}

int program(int argc, string[] argv)
{
	var pi = new int[2];
	pi[0] = 3;
	pi[1] = 14159;
	var diameter = new int[2];
	diameter[0] = 20;
	diameter[1] = 17;
	var prod = multiply_floats(pi, diameter);
	print_int(prod[0]);
	print_string(".");
	print_int(prod[1]);
	return 0;
}