Lecture: April 30, 1998
Notetaker: Elizabeth Markert

Reading Assignment: Chap. 13.1-13.4
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Refer to Code Generation Routines Part II
Arrays
Indexing

Assignment of an Array to an Array: Array1 = Array2
	*Size check
	*Make a clone of the array
	*One is actually assigning a pointer
Assignment of a string to an Array: Array = "string"
	*Convert string to a character array
	*Size check

Refer to pg. 10 of Code Gen. part II

cg(){//For asgnode	
	computeadr(target);
	source.cg();
	if source is an array
		clone it //accessible in csxlib
	else
		source is a string
		convert it to an array //accessible in csxlib
	storename(Target);
}

cg(){//namenode
	if name is a scalar
		put value onto stack
	else if name is an array
		push reference to array onto stack
	else //subscripted name
		push reference to array
		evaluate subscript
		generate ILoad or BALoad or CALoad
}

computeadr-> computes the address

computeadr(namenode){
if name is scalar
	generate nothing
else if name is an array
	push reference of array onto stack
else // subscripted value
	push reference to array
	compute subscript
}

storename(namenode){
if name is a scalar
	store value at top of stack
else if name is an array
	do a length check
	store reference on the stack
else//Subscripted value
	generate IAStore or BAStore or CAStore
}

In Java:
	char a[5]; // = new char[5];
	char b[5]; // = new char[5];
	a = b;
	a = "xyzzz";
	a[3] = 'x';
	print(b[4]);

char a[5]; // = new char[5];
char b[5]; // = new char[5];

	.field public static a$ [c
	.field public static b$ [c
	ldc 5                    //5 indexes in array
	newarray char            //new char array 
	putstatic c/a$ [c
	ldc 5
	newarray char
	putstatic c/b$ [c

a = b;  //Reference to cg() of asgnode

	getstatic c/a$ [c
	getstatic c/b$ [c
	invokestatic csxlib/cloneCharArray([c)[c
	invokestatic csxlib/checkCharArrayLength([c[c)[c
	putstatic c/a$[c

a = "xyzzz";

	getstatic c/a$ [c
	ldc "xyzzz"
	invokestatic csxlib/convertString(Java path name for string)[c
	invokestatic csxlib/checkCharArrayLength([c[c)[c
	putstatic c/a$ [c

a[3] = 'x';
	getstatic c/a$ [c
	ldc 3
	ldc 120 // character code for x
	CAStore //char array store
	//doesn't leave anything on the stack

print(b[4]);
	getstatic c/b$ [c
	ldc 4
  	CALoad //Load char onto stack
	invokestatic csxlib/printchar(c)V
	
Refer To Code Generation Routines Part III

cg(){//classnode(pg1 of part III)
	.class public class
	.super java/lang/oblect
	generate fieldDecls
	.method public static main([string)V
	generate init for fields
	call main()V
	return
	.limit stack 2
	.end method
	generate methods
}


eval args                \
call subr                 \
invokestatic c/F(II)I      \
//MethodDeclNode            \
code generated by MethodDecl \          code for calls
compute method                \
.method typecode              /         code for methodDecls
args.cg();                   /
decls.cg();                 /
stmts.cg();                /
gen return;               /
.end method;             /


int F(int a){ //a has local index = 0
	int b;//b has local index = 1
	a = a + b;
}
//Must keep track of current method

	F(I)I
	.method public static F(I)I
	ILoad 0  //load a
	ILoad 1  //load b
	IAdd
	IStore 0
	LDC 0
	IReturn
	.limit stack 25
	.limit locals 2 //number of locals used
	.end metod