CPSC 2310 - DAY 17
OCTOBER 12, 2016

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[ ] - INDICATES MEMORY ADDRESSES
 ^ needs to be an address in memory

make sure that the number of registers that are pushed are also poped from the 
stack at the end.

Parameters can easily be stored in memory

Passing parameters on the stack is similar to passing parameters in memory

the subroutine uses a dedicated register

call-by-value 
	.input parameters (declared with "IN") in Ada

	.default method parameters in C, C++, and Pascal

	.parameters of primitive type in java

call-by-value-result
	.in/out parameters (declared with "IN OUT" in Ada

call-by-reference
	.large array paramenters in Ada
	.array parameters in C and C++
	.reference parameters declared with & in C++
	.object parameters in Java

Call-by-value
	.Copy values of a actual parameters into memory locations of formal
	parameters before executing the body of the subroutine, do nothing
	on return

EX:
	main
		a=1
		b=2
		call subr(a,b) pass 1,2 via the stack
		print a,b	//print 1,2
	subr(x,y)
		x = x+1
		y = x + y
		return