Postfix Calculator

Tom Kelliher, CS 220

Due Nov. 13, 2009, with a milestone due Nov. 6

Simply, hand-compile the postfix.c program on the class home page to MIPS assembly and run under SPIM. Use typescript to record a session in which you run the expressions on the ``Postfix Calculator Test'' document (refer to the class web site) on your calculator in SPIM. Hand-in the typescript session and your commented MIPS source code.

Ground rules:

1. Frames and a frame stack must be used for all functions, including main(). This is crucial for printVal(), as this function is recursive. You may NOT implement printVal() non-recursively.

   Note that registers $fp and $sp are for the frame stack. Use $t8 (see below) for the operand stack.

2. Implement the following functions:

   int isEmpty(void);
   int isFull(void);
   void push(int item);
   int pop(void);
   int getValue(void);
   void compute(void);
   void output(void);
   void die(const char *s);
   void printVal(int v);
   int main();
   

3. Use mnemonic register names.

4. Adhere to the following MIPS conventions: call, register use, and memory use.

5. $t8 and $t9 may be used to permanently store the two external pointers (stackPointer and next).

Nov. 6 milestone: Lay-out the frame structure and write the bodies of the functions, save for main. Do not consider the call or return code for now. Hand in hard copy.

Tom Kelliher