Clairifications on how to use the immediate operand and memlabel classses:


The memlabel class maintains a counter that allows new sets of labels to be
generated:

  memlabel elselabel = new memlabel("else");  // generate new label
  memlabel exitlabel = new memlabel("endif",true); // auto-increment counter

because the counter is auto-incremented by the second calls, the next set
of calls to new memlabel will produce new labels.

 The actual string representing each label is accesible vai (eg) elselabel.name

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The immediate class has three forms:

  new immediate(3)      //  prints as $3
  new immediate("abc"); //  prints as $abc
  new immediate("abc",true)  // prints as abc  (for jump and call labels).


Here's how to add the following instructions to the Code arraylist.  assume
that the current value of the label counter (memlabel.counter) is 3:

       cmp $1, %eax
       jne  else3
       ...
       jmp exit3
else3: nop
       ...
exit3: nop   
       pushl $STR1
       call printf

corresponds to :


  memlabel elselabel = new memlabel("else");  // generate new label
  memlabel exitlabel = new memlabel("exit",true); // auto-increment counter

  Code.add(new operation("cmp",new immediate(1),EAX));  // cmp $1,eax
  Code.add(new operation("jne",new immediate(elselabel.name, true))); // jne else3
  ...
  Code.add(new operation("jmp",new immediate(exitlabel.name, true))); // jmp exit3
  Code.add(new operation(elselabel));   // else3: nop 
  ...
  Code.add(new operation(exitlabel));   // exit3: nop
  Code.add(new operation("pushl", new immediate("STR1")));   // pushl $STR1
  Code.add(new operation("call", new immediate("printf",true))); // call printf

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Another thing to remember is that you can always generate any instruction
by just passing a single string to new operation, as in:

  Code.add(new operation("call printf"));    or
  Code.add(new operation("\n exitlabel3: nop"));


However, if you do it this way, you will lose the ability to modify the code later.