Description:
------------
Currently it always traverses the bitset from bit 0 to the last one, but I think 
it could 
be rewritten to traverse the bitset backwards and stop and return the first bit 
set found 
from the end. Something like this:


PHP_METHOD(BitSet, length)
{
	php_bitset_object *intern;
	long highest_bit = -1, i = 0, total_bits = 0;

	intern = bitset_get_intern_object(getThis() TSRMLS_CC);
	total_bits = intern->bitset_len * CHAR_BIT;

        i = total_bits;

	while(i > 0)
        {
                i--;
		if (intern->bitset_val[i / CHAR_BIT] & (1 << (i % CHAR_BIT))) {
			highest_bit = i;
                        break;
		}
	}

	RETURN_LONG(highest_bit + 1);
}


I think it could also be further optimized by checking if all bits are zero one 
word at a 
time. Changing the code inside the while loop to something like this?:

                i--;

                if (intern->bitset_val[i / CHAR_BIT] == (unsigned char) 0x0) {
			i -= CHAR_BIT;
                        continue;
		}

		if (intern->bitset_val[i / CHAR_BIT] & (1 << (i % CHAR_BIT))) {
			highest_bit = i;
                        break;
		}