About Passes of a Compiler
	ä Each pass requires the traversal of the current representation of the source ä Slow, especially if the representation is not all in memory (huge source files, ......) ä Modern compilers may accomplish the work associated with more than one pass in one pass over the code ä Turbo Pascal in the 1980’s combined the work from all passes into a single pass ä Advantage was speed ä Disadvantage is that you have trouble dealing with more complex language features and problems generating efficient code