🚀 go-pugleaf

In article <4jbciv$2kk@solutions.solon.com>, vjarnot@mnw.net (Asmodeus) writes:
|> 
|> I have set up an array in the following manner (obviously I just need
|> 0 or 1) :
|> 
|> typedef struct my_bits {
|> 	unsigned the_bit : 1;
|> };
|> 
|> my_bits the_array[800][800];
|> 
|> 	My question is this : I have read that some operations ( =,+,- are
|> what I use) are slower when performed on bits as opposed to other
|> types.  My objective is to optimize the code for speed, and I figured
|> using less memory would help me do so, now I'm having doubts.  So what
|> is more efficient, bits or some other type???

If you are interested in speed, I suggest

	int the_bit [800][800];

If you are interested in space, one suggestion is

	# include	<limits.h>
	
	# define	UNSIGNED_BIT	(CHAR_BIT * sizeof (unsigned))

	struct {
		unsigned the_bits [UNSIGNED_BIT]: 1;
	} the_array [800][(800 + UNSIGNED_BIT - 1) / UNSIGNED_BIT];

	# define	BIT(X, Y)\
		the_array [Y][(X) / UNSIGNED_BIT].the_bits [(X) % UNSIGNED_BIT]

Konrad Schwarz