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CSCI 316: Final Exam Exercises

Assigned Reading

Read Section 5.2 on pp. 155-160 and the discussion of call/pass by name on p. 165 in Sethi. Also, read the comments on call/pass by value-result below. You should already understand call/pass by value and call/pass by reference, as those modes are used in C++. Most of the material on pp. 155-158 should be familiar.

There will be a problem on the final exam, worth 5 pts., similar to the examples below. (Maximum score on final exam: 40 pts.)

Slides showing the behavior of the program in Example 2 for each parameter passing mode have been posted on Brightspace: Slides–parameter-passing-examples.pdf

Example 1: Parameter Passing Modes

Based on an example in L. B. Wilson and R. G. Clark, Comparative Programming Languages, Addison-Wesley, 3rd Ed., 2001, pp. 137-138.

Complete the table below to show the output that is produced when the following program is executed. When completing each row, assume that parameters are passed by the indicated mode.

class Example {
    static int e;
    static int a[] = new int[3];

    static void test(int x) {
        a[1] = 6;
        e = 2;
        x += 3;
    }

    public static void main(String[] args) {
        a[1] = 1; a[2] = 2; e = 1;
        test(a[e]);
        System.out.println(a[1]+" "+a[2]+" "+e);
    }
}

Output for Each Parameter Passing Mode:

Passing Mode a[1] a[2] e
value      
reference      
value-result      
value-result (Algol W)      
name      
Solution
Passing Mode a[1] a[2] e
value 6 2 2
reference 9 2 2
value-result 4 2 2
value-result (Algol W) 6 4 2
name 6 5 2

Example 2: Parameter Passing (Based on an old exam question)

Complete the table below to show the output that is produced when the following program is executed. When completing each row, assume that parameters are passed by the indicated mode.

class FinalExam {
    static int e = 1;
    static int a[] = {0, 1, 2};

    public static void main(String args[]) {
        test(a[e], a[e-1]);
        System.out.println(a[0] + " " + a[1] + " " + a[2] + " " + e);
    }

    static void test(int x, int y) {
        a[1] = 6;
        e = 2;
        x += 3;
        y--;
        System.out.print(x + " " + y + " ");
    }
}

Output for Each Parameter Passing Mode:

Passing Mode x y a[0] a[1] a[2] e
value            
reference            
value-result            
value-result (Algol W)            
name            
Solution
Passing Mode x y a[0] a[1] a[2] e
value 4 -1 0 6 2 2
reference 9 -1 -1 9 2 2
value-result 4 -1 -1 4 2 2
value-result (Algol W) 4 -1 0 -1 4 2
name 5 5 0 5 5 2

Comments on Call/Pass by Value-Result

There are two subtleties relating to call/pass by value-result:

Subtlety 1: Same Variable Passed Multiple Times

If the same variable is passed as two different arguments, the final value may depend on the order in which formal parameter values are copied back into the actual argument variables’ locations.

Example: Consider a function of the form:

void p(int a, int b) {
    a = 4;
    b = 7;
}

Where parameters a and b are passed by value-result. Suppose main calls this function as:

p(j, j);
System.out.print(j);

When control returns to main from p(j, j), the following must happen:

The definition of pass by value-result doesn’t specify whether (i) or (ii) occurs first:

Important: If asked to write the output of System.out.print(j) assuming pass by value-result, the correct answer is neither “4” nor “7” — write “4 or 7”.

In Ada, pass by value-result is the default for “in out” parameters of scalar types, but Ada avoids this issue by disallowing calls like p(j,j) that pass the same variable as arguments for multiple such parameters.

Subtlety 2: Standard vs. Algol W Style Value-Result

The discussion on pp. 159-160 of Sethi applies to standard pass by value-result. A different version was used in Algol W, the first language to support pass by value-result.

Standard Pass by Value-Result

When control returns to the caller, the final value of each formal parameter is copied into the location that belonged to the corresponding actual argument variable immediately before the called function’s body was executed.

Algol W Style Pass by Value-Result

When control returns to the caller, the final value of each formal parameter is copied into the location that belongs to the corresponding actual argument variable immediately after the called function’s body is executed.

These versions may produce different results if the actual argument is an indexed variable v[expr] whose index expression expr changes value during execution of the called function’s body.

Example: Difference Between Styles

Consider this function:

void q(int c) {
    c = 55;
    i = 17;  // i is a global variable
}

Where i is global and parameter c is passed by value-result. Suppose main calls it as:

i = 23;
q(arr[i]);

Standard pass by value-result: The final value of q’s parameter c (i.e., 55) is copied into arr[23] because i’s value was 23 immediately before q’s body was executed (so arr[i] was arr[23]).

Algol W style pass by value-result: The final value of c is copied into arr[17] because i’s value is 17 immediately after q’s body is executed (so arr[i] is arr[17]).

Problem Statement 1 Relating to VM Dump Analysis

Below are questions regarding a TinyJ VM dump. The TinyJ program and its generated code/dump are provided below the questions.

The dump below below was produced when TJasn.TJ compiled the TinyJ program below and executed the generated code with a debugging stop after execution of exactly 23,172 instructions with this input sequence:

4, 5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0

Note that the INITSTKFRM instructions are at code memory addresses 4, 322, 391, and 490.

Questions Relating to the Dump

Question 1

(a) For each method, how many locations are allocated to local variables in its stackframe?

Answer 
main: 7
readRow: 2
transpose: 5
writeOut: 3
Comment

The answers are deduced from the operands of the methods’ INITSTKFRM instructions at code memory addresses 4, 322, 391, and 490.

It is also possible to work out the answers from the local variable declarations in each method. In main(), for example, the local variables r, c, n, and layer are given the stackframe offsets 1, 2, 3, and 4; i is given offset 5; h is given offset 6; and j is given offset 7.

Note that the scopes of local variable declarations need to be taken into account. Thus if we add a declaration of a local variable hh inside the block of the while (h <= layer) { ... } loop that follows the declaration of h, then both hh and j will be given the offset 7 because the scopes of the declarations of hh and j will not overlap.

(b) Write down the size of a stackframe for readRow(), transpose(), and writeOut()

Answer 
readRow: 7
transpose: 10
writeOut: 8
Comment

For any method other than main():

$\text{stackframe size} = \text{no. of parameters} + 2 + \text{no. of locations allocated to local vars}$

The 2 extra locations are for the dynamic link (at offset 0) and the return address (at offset −1).

For main():

$\text{stackframe size} = 1 + \text{no. of locations allocated to local vars}$

In TinyJ, main() is not called by another method and its stackframe has no return address. The INITSTKFRM instruction always allocates a location (offset 0) for a dynamic link, but in the case of main() that location serves no purpose and always points to the illegal data memory address 20000.

Note: The highest legal data memory address is 19999; data memory addresses 10000–19999 are reserved for use as heap memory.

Questions 2 – 9: VM State

Questions 2 – 9 below are about the state of the TinyJ virtual machine at the time of the debugging stop after execution of 23,172 instructions:

Question 2

Consider the static variables mat, count, and tm. What values are stored in the following locations?

(a) count

Answer 
1

(b) mat[2][4]

Answer 
5

(c) tm[0][3][2]

Answer 
8
Comment

mat’s address is 0, count’s address is 1, and tm’s address is 2.

Questions (b) and (c) are intended to test your understanding of arrays.

For (c), the solution is as follows:

Question 3

Which method is being executed?

Answer 
writeOut
Comment

From the addresses of the INITSTKFRM instructions, we see:

Method Code Address Range
main 4–321
readRow 322–390
transpose 391–489
writeOut 490–607

The last instruction to be executed was at 502 (as stated on the 5th-last line of the dump). This is within writeOut’s code.

Question 4

Which data memory locations constitute the stackframe of the executing method?

Answer 
addresses 200 through 207
Comment

From FP, we see that offset 0 of the stackframe is at address 204. The beginning and end of the stackframe can be deduced from this and the answers to questions 1(a) and 1(b) for writeOut.

Question 5

What values are stored in the stackframe locations of the local variables and formal parameters of the executing method?

Answer 
i = 742
j = 0
mm = null
rows = -2
cols = 0
matr[][] = PTR to 10085
Comment

The answers are deduced from the stackframe offsets of the parameters and variables, and the fact that offset 0 is at address 204.

Note: The variables j and mm are not in scope in the while (i < 1000) loop that is being executed at this time. Therefore, the values stored in the locations of j and mm are just “garbage” values.

Question 6

Which method called the executing method?

Answer 
writeOut
Comment

The return address at offset −1 (address 203) is 568. This is within writeOut’s code.

Question 7

Which method called the caller?

Answer 
readRow
Comment

The dynamic link in the stackframe of the currently executing method points to address 196. Following the chain of dynamic links:

Thus, 196, 189, 179, and 165 are the addresses of the offset 0 locations in the stackframes of:

The return addresses stored in the first three of these stackframes (at addresses 195, 188, and 178) are 361, 473, and 199, which are instructions in the code of readRow, transpose, and main, respectively.

Alternatively, we can determine that the caller’s caller’s caller’s caller is main by observing that offset 0 in its stackframe (address 165) points to the illegal data memory address 20000—see the comment on question 1(b).

Question 8

Which method called the caller’s caller? And which method called that method?

Answer 
transpose;
main
Comment

The dynamic link in the stackframe of the currently executing method points to address 196. Following the chain of dynamic links:

Thus, 196, 189, 179, and 165 are the addresses of the offset 0 locations in the stackframes of:

The return addresses stored in the first three of these stackframes (at addresses 195, 188, and 178) are 361, 473, and 199, which are instructions in the code of readRow, transpose, and main, respectively.

Alternatively, we can determine that the caller’s caller’s caller’s caller is main by observing that offset 0 in its stackframe (address 165) points to the illegal data memory address 20000—see the comment on question 1(b).

Question 9

What are the addresses of main’s local variables h and j?

Answer 
h's address: 171
j's address: 172
Comment

Offset 0 in main’s frame is at address 165 (see comments on questions 7 and 8). h’s stackframe offset is 6 and j’s is 7.

Questions 10-15: Future Execution (If Debugging Stop Had Not Occurred)

Question 10: Next 10 Instructions to Execute

What would be the code memory addresses of the next 10 instructions to be executed (23,173rd through 23,182nd)?

Answer 
503 through 511, then 500
Comment

PC contains 503, so 503: LT is the first of the 10 instructions.

From the last few lines of the dump, at this time:

Thus, 1000 is on top of EXPRSTACK and 742 is the second item from the top.

Since $742 < 1000$, execution of LT replaces these two integers with the value 1 (which represents true). Therefore, the JUMPONFALSE at 504 does not jump after popping off this value.

Question 11: Output from Next 10 Instructions

What output, if any, would be produced by execution of those 10 instructions?

Answer 
None
Comment

Only WRITEINT, WRITESTRING, and WRITELNOP produce output.

Question 12: Data Memory Changes

Which data memory locations, if any, would be changed in value by execution of the 10 instructions? Name the variable(s) whose values are stored there.

Answer 
address 205; i
Comment

Data memory is changed only by SAVETOADDR, PASSPARAM, CALLSTATMETHOD, INITSTKFRM, and HEAPALLOC. The only one of these that is executed here is SAVETOADDR (at 510).

When this is executed, the pointer that is second from top on EXPRSTACK was put there by 505: PUSHLOCADDR 1. This refers to offset 1 in the currently executing method’s stackframe, which is the location of i and has address 205 (since offset 0 has address 204).

Note on HEAPALLOC: HEAPALLOC changes data memory only because it sets the location that immediately precedes the block of heap memory it allocates to point to the location that immediately follows the block. This allows allocated blocks of heap memory that have become inaccessible to be deallocated by the garbage collector and makes it possible to check at runtime that every array index is less than the length of the array.

Question 13: Register Values After First 3 Instructions

Write down PC, FP, ASP, and ESP registers after execution of the first 3 of the 10 instructions. Also write the value or values of EXPRSTACK[j] for 0 ≤ j < ESP.

Answer 
PC = 506
FP = PTR TO 204
ASP = PTR TO 208
ESP = 1
EXPRSTACK[0] = PTR TO 205
Comment

Questions like these are intended to test your understanding of what specific machine instructions do to the TinyJ VM. Here, the instructions you are being tested on are LT, JUMPONFALSE, PUSHLOCADDR, and RETURN.

Question 14: Register Values on RETURN

When the currently executing method activation RETURNs to its caller, what will PC, FP, and ASP be set to?

Answer 
PC = 568
FP = PTR TO 196
ASP = PTR TO 200
Comment

RETURN must perform the following operations:

  1. Set FP to point to offset 0 in the caller’s stackframe (the dynamic link is a pointer to that location)
  2. Set PC to the return address
  3. Set ASP to point to the first location (the location with the most negative offset) in the currently executing method activation’s stackframe; this will deallocate the stackframe

The dynamic link and return address are respectively stored at offset 0 and offset −1 in the currently executing method activation’s stackframe.

Question 15: Repeat Q10-13 with Modified Instruction

Answer questions 10-12 and 13 again under the (very unlikely!) assumption that immediately before executing the 23,173rd instruction, soft errors change the LT instruction at code memory address 503 to a GE instruction.

Answer 
Addresses: 503 and 504, then 512-519

Output: 1 then newline

Data memory: No data memory location's value is changed

After first 3 instructions:
  PC = 513
  FP = PTR TO 204
  ASP = PTR TO 208
  ESP = 1
  EXPRSTACK[0] = PTR TO 1
Comment

Questions like these are intended to test your understanding of what specific machine instructions do to the TinyJ VM. Here, the instructions you are being tested on are LT, JUMPONFALSE, PUSHLOCADDR, and RETURN.

TinyJ Program and Dump

TinyJ Program

import java.util.Scanner;

class DumpEx {
    static int mat[][], count;
    static int tm[][][] = new int[5][][];

    public static void main(String args[]) {
        int r[] = new int[5], c[] = new int[5], n = 1;
        int layer = -1;
        while (n == 1) {
            if (layer < 4)
                layer = layer + 1;
            else
                layer = 0;

            Scanner input = new Scanner(System.in);

            System.out.print("Enter number of rows: ");
            r[layer] = input.nextInt();
            System.out.print("Enter number of columns: ");
            c[layer] = input.nextInt();

            mat = new int[r[layer]][];
            tm[layer] = mat;

            int i = 0;
            while (i < r[layer]) {
                mat[i] = new int[c[layer]];
                readRow(i + 1, mat[i], c[layer]);
                i = i + 1;
            }

            int h = 0;
            while (h <= layer) {
                System.out.println("Given matrix: ");
                writeOut(r[h], c[h], tm[h]);
                System.out.println("Transposed matrix: ");
                writeOut(c[h], r[h], transpose(tm[h], r[h], c[h]));
                h = h + 1;
            }

            System.out.println("Doubled matrices: ");

            h = 0;
            while (h <= layer) {
                i = 0;
                while (i < r[h]) {
                    int j = 0;
                    while (j < c[h]) {
                        tm[h][i][j] = tm[h][i][j] * 2;
                        System.out.print(tm[h][i][j]);
                        System.out.print(" ");
                        j = j + 1;
                    }
                    System.out.println();
                    i = i + 1;
                }
                h = h + 1;
                System.out.println("\n");
            }

            System.out.print("\n\nType 1 to continue, 0 to quit: ");
            n = input.nextInt();
        }
    }

    static void readRow(int rowNum, int m[], int c) {
        if (rowNum >= 0) {
            System.out.print("Row ");
            System.out.println(rowNum);
        }

        int i = 0;
        while (i < c) {
            if (rowNum == -1) {
                int mm[][] = new int[1][];
                writeOut(-1, 10, mm);
                i = i + 1;
            } else {
                Scanner input = new Scanner(System.in);
                System.out.print("Enter value in column ");
                System.out.print(i + 1);
                System.out.print(": ");
                m[i] = input.nextInt();
                i = i + 1;
            }
        }
    }

    static int[][] transpose(int m[][], int r, int c) {
        int k, i, m1[][] = new int[c][];
        k = 0;

        while (k < c) {
            m1[k] = new int[r];
            k = k + 1;
        }

        i = 0;
        while (i < r) {
            int j = 0;
            while (j < c) {
                m1[j][i] = m[i][j];
                int mm[] = new int[1];
                readRow(-1, mm, 10);
                j = j + 1;
            }
            i = i + 1;
        }

        return m1;
    }

    static void writeOut(int rows, int cols, int matr[][]) {
        int i = 0;

        if (rows == -2) {
            while (i < 1000) i = i + 1;
            System.out.println(count);
            count = count + 1;
        }
        while (i < rows | rows == -1 & i < cols) {
            int j = 0;
            while (j < cols) {
                if (rows == -1) {
                    int mm[][] = new int[1][];
                    writeOut(-2, 0, mm);
                    j = j + 1;
                } else {
                    System.out.print(matr[i][j]);
                    System.out.print(" ");
                    j = j + 1;
                }
            }
            if (rows >= 0)
                System.out.println();
            i = i + 1;
        }
    }
}

Generated Code

  0: PUSHSTATADDR       2
  1: PUSHNUM            5
  2: HEAPALLOC           
  3: SAVETOADDR          
  4: INITSTKFRM         7
  5: PUSHLOCADDR        1
  6: PUSHNUM            5
  7: HEAPALLOC           
  8: SAVETOADDR          
  9: PUSHLOCADDR        2
 10: PUSHNUM            5
 11: HEAPALLOC           
 12: SAVETOADDR          
 13: PUSHLOCADDR        3
 14: PUSHNUM            1
 15: SAVETOADDR          
 16: PUSHLOCADDR        4
 17: PUSHNUM            1
 18: CHANGESIGN          
 19: SAVETOADDR          
 20: PUSHLOCADDR        3
 21: LOADFROMADDR        
 22: PUSHNUM            1
 23: EQ                  
 24: JUMPONFALSE      321
 25: PUSHLOCADDR        4
 26: LOADFROMADDR        
 27: PUSHNUM            4
 28: LT                  
 29: JUMPONFALSE       37
 30: PUSHLOCADDR        4
 31: PUSHLOCADDR        4
 32: LOADFROMADDR        
 33: PUSHNUM            1
 34: ADD                 
 35: SAVETOADDR          
 36: JUMP              40
 37: PUSHLOCADDR        4

 38: PUSHNUM            0
 39: SAVETOADDR          
 40: WRITESTRING        3   24
 41: PUSHLOCADDR        1
 42: LOADFROMADDR        
 43: PUSHLOCADDR        4
 44: LOADFROMADDR        
 45: ADDTOPTR            
 46: READINT             
 47: SAVETOADDR          
 48: WRITESTRING       25   49
 49: PUSHLOCADDR        2
 50: LOADFROMADDR        
 51: PUSHLOCADDR        4
 52: LOADFROMADDR        
 53: ADDTOPTR            
 54: READINT             
 55: SAVETOADDR          
 56: PUSHSTATADDR       0
 57: PUSHLOCADDR        1
 58: LOADFROMADDR        
 59: PUSHLOCADDR        4
 60: LOADFROMADDR        
 61: ADDTOPTR            
 62: LOADFROMADDR        
 63: HEAPALLOC           
 64: SAVETOADDR          
 65: PUSHSTATADDR       2
 66: LOADFROMADDR        
 67: PUSHLOCADDR        4
 68: LOADFROMADDR        
 69: ADDTOPTR            
 70: PUSHSTATADDR       0
 71: LOADFROMADDR        
 72: SAVETOADDR          
 73: PUSHLOCADDR        5
 74: PUSHNUM            0
 75: SAVETOADDR          

 76: PUSHLOCADDR        5
 77: LOADFROMADDR        
 78: PUSHLOCADDR        1
 79: LOADFROMADDR        
 80: PUSHLOCADDR        4
 81: LOADFROMADDR        
 82: ADDTOPTR            
 83: LOADFROMADDR        
 84: LT                  
 85: JUMPONFALSE      127
 86: PUSHSTATADDR       0
 87: LOADFROMADDR        
 88: PUSHLOCADDR        5
 89: LOADFROMADDR        
 90: ADDTOPTR            
 91: PUSHLOCADDR        2
 92: LOADFROMADDR        
 93: PUSHLOCADDR        4
 94: LOADFROMADDR        
 95: ADDTOPTR            
 96: LOADFROMADDR        
 97: HEAPALLOC           
 98: SAVETOADDR          
 99: PUSHLOCADDR        5
100: LOADFROMADDR        
101: PUSHNUM            1
102: ADD                 
103: PASSPARAM           
104: PUSHSTATADDR       0
105: LOADFROMADDR        
106: PUSHLOCADDR        5
107: LOADFROMADDR        
108: ADDTOPTR            
109: LOADFROMADDR        
110: PASSPARAM           
111: PUSHLOCADDR        2
112: LOADFROMADDR        
113: PUSHLOCADDR        4

114: LOADFROMADDR        
115: ADDTOPTR            
116: LOADFROMADDR        
117: PASSPARAM           
118: CALLSTATMETHOD   322
119: NOP                 
120: PUSHLOCADDR        5
121: PUSHLOCADDR        5
122: LOADFROMADDR        
123: PUSHNUM            1
124: ADD                 
125: SAVETOADDR          
126: JUMP              76
127: PUSHLOCADDR        6
128: PUSHNUM            0
129: SAVETOADDR          
130: PUSHLOCADDR        6
131: LOADFROMADDR        
132: PUSHLOCADDR        4
133: LOADFROMADDR        
134: LE                  
135: JUMPONFALSE      209
136: WRITESTRING       50   63
137: WRITELNOP           
138: PUSHLOCADDR        1
139: LOADFROMADDR        
140: PUSHLOCADDR        6
141: LOADFROMADDR        
142: ADDTOPTR            
143: LOADFROMADDR        
144: PASSPARAM           
145: PUSHLOCADDR        2
146: LOADFROMADDR        
147: PUSHLOCADDR        6
148: LOADFROMADDR        
149: ADDTOPTR            
150: LOADFROMADDR        
151: PASSPARAM           

152: PUSHSTATADDR       2
153: LOADFROMADDR        
154: PUSHLOCADDR        6
155: LOADFROMADDR        
156: ADDTOPTR            
157: LOADFROMADDR        
158: PASSPARAM           
159: CALLSTATMETHOD   490
160: NOP                 
161: WRITESTRING       64   82
162: WRITELNOP           
163: PUSHLOCADDR        2
164: LOADFROMADDR        
165: PUSHLOCADDR        6
166: LOADFROMADDR        
167: ADDTOPTR            
168: LOADFROMADDR        
169: PASSPARAM           
170: PUSHLOCADDR        1
171: LOADFROMADDR        
172: PUSHLOCADDR        6
173: LOADFROMADDR        
174: ADDTOPTR            
175: LOADFROMADDR        
176: PASSPARAM           
177: PUSHSTATADDR       2
178: LOADFROMADDR        
179: PUSHLOCADDR        6
180: LOADFROMADDR        
181: ADDTOPTR            
182: LOADFROMADDR        
183: PASSPARAM           
184: PUSHLOCADDR        1
185: LOADFROMADDR        
186: PUSHLOCADDR        6
187: LOADFROMADDR        
188: ADDTOPTR            
189: LOADFROMADDR        

190: PASSPARAM           
191: PUSHLOCADDR        2
192: LOADFROMADDR        
193: PUSHLOCADDR        6
194: LOADFROMADDR        
195: ADDTOPTR            
196: LOADFROMADDR        
197: PASSPARAM           
198: CALLSTATMETHOD   391
199: PASSPARAM           
200: CALLSTATMETHOD   490
201: NOP                 
202: PUSHLOCADDR        6
203: PUSHLOCADDR        6
204: LOADFROMADDR        
205: PUSHNUM            1
206: ADD                 
207: SAVETOADDR          
208: JUMP             130
209: WRITESTRING       83  100
210: WRITELNOP           
211: PUSHLOCADDR        6
212: PUSHNUM            0
213: SAVETOADDR          
214: PUSHLOCADDR        6
215: LOADFROMADDR        
216: PUSHLOCADDR        4
217: LOADFROMADDR        
218: LE                  
219: JUMPONFALSE      316
220: PUSHLOCADDR        5
221: PUSHNUM            0
222: SAVETOADDR          
223: PUSHLOCADDR        5
224: LOADFROMADDR        
225: PUSHLOCADDR        1
226: LOADFROMADDR        
227: PUSHLOCADDR        6

228: LOADFROMADDR        
229: ADDTOPTR            
230: LOADFROMADDR        
231: LT                  
232: JUMPONFALSE      307
233: PUSHLOCADDR        7
234: PUSHNUM            0
235: SAVETOADDR          
236: PUSHLOCADDR        7
237: LOADFROMADDR        
238: PUSHLOCADDR        2
239: LOADFROMADDR        
240: PUSHLOCADDR        6
241: LOADFROMADDR        
242: ADDTOPTR            
243: LOADFROMADDR        
244: LT                  
245: JUMPONFALSE      299
246: PUSHSTATADDR       2
247: LOADFROMADDR        
248: PUSHLOCADDR        6
249: LOADFROMADDR        
250: ADDTOPTR            
251: LOADFROMADDR        
252: PUSHLOCADDR        5
253: LOADFROMADDR        
254: ADDTOPTR            
255: LOADFROMADDR        
256: PUSHLOCADDR        7
257: LOADFROMADDR        
258: ADDTOPTR            
259: PUSHSTATADDR       2
260: LOADFROMADDR        
261: PUSHLOCADDR        6
262: LOADFROMADDR        
263: ADDTOPTR            
264: LOADFROMADDR        
265: PUSHLOCADDR        5

266: LOADFROMADDR        
267: ADDTOPTR            
268: LOADFROMADDR        
269: PUSHLOCADDR        7
270: LOADFROMADDR        
271: ADDTOPTR            
272: LOADFROMADDR        
273: PUSHNUM            2
274: MUL                 
275: SAVETOADDR          
276: PUSHSTATADDR       2
277: LOADFROMADDR        
278: PUSHLOCADDR        6
279: LOADFROMADDR        
280: ADDTOPTR            
281: LOADFROMADDR        
282: PUSHLOCADDR        5
283: LOADFROMADDR        
284: ADDTOPTR            
285: LOADFROMADDR        
286: PUSHLOCADDR        7
287: LOADFROMADDR        
288: ADDTOPTR            
289: LOADFROMADDR        
290: WRITEINT            
291: WRITESTRING      101  101
292: PUSHLOCADDR        7
293: PUSHLOCADDR        7
294: LOADFROMADDR        
295: PUSHNUM            1
296: ADD                 
297: SAVETOADDR          
298: JUMP             236
299: WRITELNOP           
300: PUSHLOCADDR        5
301: PUSHLOCADDR        5
302: LOADFROMADDR        
303: PUSHNUM            1

304: ADD                 
305: SAVETOADDR          
306: JUMP             223
307: PUSHLOCADDR        6
308: PUSHLOCADDR        6
309: LOADFROMADDR        
310: PUSHNUM            1
311: ADD                 
312: SAVETOADDR          
313: WRITESTRING      102  102
314: WRITELNOP           
315: JUMP             214
316: WRITESTRING      103  135
317: PUSHLOCADDR        3
318: READINT             
319: SAVETOADDR          
320: JUMP              20
321: STOP                
322: INITSTKFRM         2
323: PUSHLOCADDR       -4
324: LOADFROMADDR        
325: PUSHNUM            0
326: GE                  
327: JUMPONFALSE      333
328: WRITESTRING      136  139
329: PUSHLOCADDR       -4
330: LOADFROMADDR        
331: WRITEINT            
332: WRITELNOP           
333: PUSHLOCADDR        1
334: PUSHNUM            0
335: SAVETOADDR          
336: PUSHLOCADDR        1
337: LOADFROMADDR        
338: PUSHLOCADDR       -2
339: LOADFROMADDR        
340: LT                  
341: JUMPONFALSE      390

342: PUSHLOCADDR       -4
343: LOADFROMADDR        
344: PUSHNUM            1
345: CHANGESIGN          
346: EQ                  
347: JUMPONFALSE      369
348: PUSHLOCADDR        2
349: PUSHNUM            1
350: HEAPALLOC           
351: SAVETOADDR          
352: PUSHNUM            1
353: CHANGESIGN          
354: PASSPARAM           
355: PUSHNUM           10
356: PASSPARAM           
357: PUSHLOCADDR        2
358: LOADFROMADDR        
359: PASSPARAM           
360: CALLSTATMETHOD   490
361: NOP                 
362: PUSHLOCADDR        1
363: PUSHLOCADDR        1
364: LOADFROMADDR        
365: PUSHNUM            1
366: ADD                 
367: SAVETOADDR          
368: JUMP             389
369: WRITESTRING      140  161
370: PUSHLOCADDR        1
371: LOADFROMADDR        
372: PUSHNUM            1
373: ADD                 
374: WRITEINT            
375: WRITESTRING      162  163
376: PUSHLOCADDR       -3
377: LOADFROMADDR        
378: PUSHLOCADDR        1
379: LOADFROMADDR        

380: ADDTOPTR            
381: READINT             
382: SAVETOADDR          
383: PUSHLOCADDR        1
384: PUSHLOCADDR        1
385: LOADFROMADDR        
386: PUSHNUM            1
387: ADD                 
388: SAVETOADDR          
389: JUMP             336
390: RETURN             3
391: INITSTKFRM         5
392: PUSHLOCADDR        3
393: PUSHLOCADDR       -2
394: LOADFROMADDR        
395: HEAPALLOC           
396: SAVETOADDR          
397: PUSHLOCADDR        1
398: PUSHNUM            0
399: SAVETOADDR          
400: PUSHLOCADDR        1
401: LOADFROMADDR        
402: PUSHLOCADDR       -2
403: LOADFROMADDR        
404: LT                  
405: JUMPONFALSE      422
406: PUSHLOCADDR        3
407: LOADFROMADDR        
408: PUSHLOCADDR        1
409: LOADFROMADDR        
410: ADDTOPTR            
411: PUSHLOCADDR       -3
412: LOADFROMADDR        
413: HEAPALLOC           
414: SAVETOADDR          
415: PUSHLOCADDR        1
416: PUSHLOCADDR        1
417: LOADFROMADDR        

418: PUSHNUM            1
419: ADD                 
420: SAVETOADDR          
421: JUMP             400
422: PUSHLOCADDR        2
423: PUSHNUM            0
424: SAVETOADDR          
425: PUSHLOCADDR        2
426: LOADFROMADDR        
427: PUSHLOCADDR       -3
428: LOADFROMADDR        
429: LT                  
430: JUMPONFALSE      487
431: PUSHLOCADDR        4
432: PUSHNUM            0
433: SAVETOADDR          
434: PUSHLOCADDR        4
435: LOADFROMADDR        
436: PUSHLOCADDR       -2
437: LOADFROMADDR        
438: LT                  
439: JUMPONFALSE      480
440: PUSHLOCADDR        3
441: LOADFROMADDR        
442: PUSHLOCADDR        4
443: LOADFROMADDR        
444: ADDTOPTR            
445: LOADFROMADDR        
446: PUSHLOCADDR        2
447: LOADFROMADDR        
448: ADDTOPTR            
449: PUSHLOCADDR       -4
450: LOADFROMADDR        
451: PUSHLOCADDR        2
452: LOADFROMADDR        
453: ADDTOPTR            
454: LOADFROMADDR        
455: PUSHLOCADDR        4

456: LOADFROMADDR        
457: ADDTOPTR            
458: LOADFROMADDR        
459: SAVETOADDR          
460: PUSHLOCADDR        5
461: PUSHNUM            1
462: HEAPALLOC           
463: SAVETOADDR          
464: PUSHNUM            1
465: CHANGESIGN          
466: PASSPARAM           
467: PUSHLOCADDR        5
468: LOADFROMADDR        
469: PASSPARAM           
470: PUSHNUM           10
471: PASSPARAM           
472: CALLSTATMETHOD   322
473: PUSHLOCADDR        4
474: PUSHLOCADDR        4
475: LOADFROMADDR        
476: PUSHNUM            1
477: ADD                 
478: SAVETOADDR          
479: JUMP             434
480: PUSHLOCADDR        2
481: PUSHLOCADDR        2
482: LOADFROMADDR        
483: PUSHNUM            1
484: ADD                 
485: SAVETOADDR          
486: JUMP             425
487: PUSHLOCADDR        3
488: LOADFROMADDR        
489: RETURN             3
490: INITSTKFRM         3
491: PUSHLOCADDR        1
492: PUSHNUM            0
493: SAVETOADDR          

494: PUSHLOCADDR       -4
495: LOADFROMADDR        
496: PUSHNUM            2
497: CHANGESIGN          
498: EQ                  
499: JUMPONFALSE      522
500: PUSHLOCADDR        1
501: LOADFROMADDR        
502: PUSHNUM         1000
503: LT                  
504: JUMPONFALSE      512
505: PUSHLOCADDR        1
506: PUSHLOCADDR        1
507: LOADFROMADDR        
508: PUSHNUM            1
509: ADD                 
510: SAVETOADDR          
511: JUMP             500
512: PUSHSTATADDR       1
513: LOADFROMADDR        
514: WRITEINT            
515: WRITELNOP           
516: PUSHSTATADDR       1
517: PUSHSTATADDR       1
518: LOADFROMADDR        
519: PUSHNUM            1
520: ADD                 
521: SAVETOADDR          
522: PUSHLOCADDR        1
523: LOADFROMADDR        
524: PUSHLOCADDR       -4
525: LOADFROMADDR        
526: LT                  
527: PUSHLOCADDR       -4
528: LOADFROMADDR        
529: PUSHNUM            1
530: CHANGESIGN          
531: EQ                  

532: PUSHLOCADDR        1
533: LOADFROMADDR        
534: PUSHLOCADDR       -3
535: LOADFROMADDR        
536: LT                  
537: AND                 
538: OR                  
539: JUMPONFALSE      607
540: PUSHLOCADDR        2
541: PUSHNUM            0
542: SAVETOADDR          
543: PUSHLOCADDR        2
544: LOADFROMADDR        
545: PUSHLOCADDR       -3
546: LOADFROMADDR        
547: LT                  
548: JUMPONFALSE      594
549: PUSHLOCADDR       -4
550: LOADFROMADDR        
551: PUSHNUM            1
552: CHANGESIGN          
553: EQ                  
554: JUMPONFALSE      575
555: PUSHLOCADDR        3
556: PUSHNUM            1
557: HEAPALLOC           
558: SAVETOADDR          
559: PUSHNUM            2
560: CHANGESIGN          
561: PASSPARAM           
562: PUSHNUM            0
563: PASSPARAM           
564: PUSHLOCADDR        3
565: LOADFROMADDR        
566: PASSPARAM           
567: CALLSTATMETHOD   490
568: PUSHLOCADDR        2
569: PUSHLOCADDR        2

570: LOADFROMADDR        
571: PUSHNUM            1
572: ADD                 
573: SAVETOADDR          
574: JUMP             593
575: PUSHLOCADDR       -2
576: LOADFROMADDR        
577: PUSHLOCADDR        1
578: LOADFROMADDR        
579: ADDTOPTR            
580: LOADFROMADDR        
581: PUSHLOCADDR        2
582: LOADFROMADDR        
583: ADDTOPTR            
584: LOADFROMADDR        
585: WRITEINT            
586: WRITESTRING      164  164
587: PUSHLOCADDR        2
588: PUSHLOCADDR        2
589: LOADFROMADDR        
590: PUSHNUM            1
591: ADD                 
592: SAVETOADDR          
593: JUMP             543
594: PUSHLOCADDR       -4
595: LOADFROMADDR        
596: PUSHNUM            0
597: GE                  
598: JUMPONFALSE      600
599: WRITELNOP           
600: PUSHLOCADDR        1
601: PUSHLOCADDR        1
602: LOADFROMADDR        
603: PUSHNUM            1
604: ADD                 
605: SAVETOADDR          
606: JUMP             522
607: RETURN             3

****** Debugging Stop ******

Data Memory Dump

Data memory dump
Data memory--addresses 0 to top of
stack, and allocated heap locations:

0: 2147428131 = PTR TO 10019
1: 1 = Ctrl-A
2: 2147428113 = PTR TO 10001
3: 69 = 'E'
4: 110 = 'n'
5: 116 = 't'
6: 101 = 'e'
7: 114 = 'r'
8: 32 = ' '
9: 110 = 'n'
10: 117 = 'u'
11: 109 = 'm'
12: 98 = 'b'
13: 101 = 'e'
14: 114 = 'r'
15: 32 = ' '
16: 111 = 'o'
17: 102 = 'f'
18: 32 = ' '
19: 114 = 'r'
20: 111 = 'o'
21: 119 = 'w'
22: 115 = 's'
23: 58 = ':'
24: 32 = ' '
25: 69 = 'E'
26: 110 = 'n'
27: 116 = 't'
28: 101 = 'e'
29: 114 = 'r'
30: 32 = ' '
31: 110 = 'n'
32: 117 = 'u'
33: 109 = 'm'
34: 98 = 'b'


35: 101 = 'e'
36: 114 = 'r'
37: 32 = ' '
38: 111 = 'o'
39: 102 = 'f'
40: 32 = ' '
41: 99 = 'c'
42: 111 = 'o'
43: 108 = 'l'
44: 117 = 'u'
45: 109 = 'm'
46: 110 = 'n'
47: 115 = 's'
48: 58 = ':'
49: 32 = ' '
50: 71 = 'G'
51: 105 = 'i'
52: 118 = 'v'
53: 101 = 'e'
54: 110 = 'n'
55: 32 = ' '
56: 109 = 'm'
57: 97 = 'a'
58: 116 = 't'
59: 114 = 'r'
60: 105 = 'i'
61: 120 = 'x'
62: 58 = ':'
63: 32 = ' '
64: 84 = 'T'
65: 114 = 'r'
66: 97 = 'a'
67: 110 = 'n'
68: 115 = 's'
69: 112 = 'p'
70: 111 = 'o'
71: 115 = 's'
72: 101 = 'e'

73: 100 = 'd'
74: 32 = ' '
75: 109 = 'm'
76: 97 = 'a'
77: 116 = 't'
78: 114 = 'r'
79: 105 = 'i'
80: 120 = 'x'
81: 58 = ':'
82: 32 = ' '
83: 68 = 'D'
84: 111 = 'o'
85: 117 = 'u'
86: 98 = 'b'
87: 108 = 'l'
88: 101 = 'e'
89: 100 = 'd'
90: 32 = ' '
91: 109 = 'm'
92: 97 = 'a'
93: 116 = 't'
94: 114 = 'r'
95: 105 = 'i'
96: 99 = 'c'
97: 101 = 'e'
98: 115 = 's'
99: 58 = ':'
100: 32 = ' '
101: 32 = ' '
102: 10 = Ctrl-J
103: 10 = Ctrl-J
104: 10 = Ctrl-J
105: 84 = 'T'
106: 121 = 'y'
107: 112 = 'p'
108: 101 = 'e'
109: 32 = ' '
110: 49 = '1'

111: 32 = ' '
112: 116 = 't'
113: 111 = 'o'
114: 32 = ' '
115: 99 = 'c'
116: 111 = 'o'
117: 110 = 'n'
118: 116 = 't'
119: 105 = 'i'
120: 110 = 'n'
121: 117 = 'u'
122: 101 = 'e'
123: 44 = ','
124: 32 = ' '
125: 48 = '0'
126: 32 = ' '
127: 116 = 't'
128: 111 = 'o'
129: 32 = ' '
130: 113 = 'q'
131: 117 = 'u'
132: 105 = 'i'
133: 116 = 't'
134: 58 = ':'
135: 32 = ' '
136: 82 = 'R'
137: 111 = 'o'
138: 119 = 'w'
139: 32 = ' '
140: 69 = 'E'
141: 110 = 'n'
142: 116 = 't'
143: 101 = 'e'
144: 114 = 'r'
145: 32 = ' '
146: 118 = 'v'
147: 97 = 'a'
148: 108 = 'l'

149: 117 = 'u'
150: 101 = 'e'
151: 32 = ' '
152: 105 = 'i'
153: 110 = 'n'
154: 32 = ' '
155: 99 = 'c'
156: 111 = 'o'
157: 108 = 'l'
158: 117 = 'u'
159: 109 = 'm'
160: 110 = 'n'
161: 32 = ' '
162: 58 = ':'
163: 32 = ' '
164: 32 = ' '
165: 2147438112 = PTR TO 20000
166: 2147428119 = PTR TO 10007
167: 2147428125 = PTR TO 10013
168: 1 = Ctrl-A
169: 0 = Ctrl-@
170: 4 = Ctrl-D
171: 0 = Ctrl-@
172: 0 = Ctrl-@
173: 5 = Ctrl-E
174: 4 = Ctrl-D
175: 2147428131 = PTR TO 10019
176: 4 = Ctrl-D
177: 5 = Ctrl-E
178: 199
179: 2147418277 = PTR TO 165
180: 5 = Ctrl-E
181: 0 = Ctrl-@
182: 2147428160 = PTR TO 10048
183: 0 = Ctrl-@
184: 2147428191 = PTR TO 10079
185: -1
186: 2147428191 = PTR TO 10079

187: 10 = Ctrl-J
188: 473
189: 2147418291 = PTR TO 179
190: 0 = Ctrl-@
191: 2147428193 = PTR TO 10081
192: -1
193: 10 = Ctrl-J
194: 2147428193 = PTR TO 10081
195: 361
196: 2147418301 = PTR TO 189
197: 0 = Ctrl-@
198: 1 = Ctrl-A
199: 2147428197 = PTR TO 10085
200: -2
201: 0 = Ctrl-@
202: 2147428197 = PTR TO 10085
203: 568
204: 2147418308 = PTR TO 196
205: 742
206: 0 = Ctrl-@
207: 0 = Ctrl-@
10000: 2147428118 = PTR TO 10006
10001: 2147428131 = PTR TO 10019
10002: 0 = Ctrl-@
10003: 0 = Ctrl-@
10004: 0 = Ctrl-@
10005: 0 = Ctrl-@
10006: 2147428124 = PTR TO 10012
10007: 4 = Ctrl-D
10008: 0 = Ctrl-@
10009: 0 = Ctrl-@
10010: 0 = Ctrl-@
10011: 0 = Ctrl-@
10012: 2147428130 = PTR TO 10018
10013: 5 = Ctrl-E
10014: 0 = Ctrl-@
10015: 0 = Ctrl-@
10016: 0 = Ctrl-@

10017: 0 = Ctrl-@
10018: 2147428135 = PTR TO 10023
10019: 2147428136 = PTR TO 10024
10020: 2147428142 = PTR TO 10030
10021: 2147428148 = PTR TO 10036
10022: 2147428154 = PTR TO 10042
10023: 2147428141 = PTR TO 10029
10024: 1 = Ctrl-A
10025: 2 = Ctrl-B
10026: 3 = Ctrl-C
10027: 4 = Ctrl-D
10028: 5 = Ctrl-E
10029: 2147428147 = PTR TO 10035
10030: 6 = Ctrl-F
10031: 7 = Ctrl-G
10032: 8 = Ctrl-H
10033: 9 = Ctrl-I
10034: 0 = Ctrl-@
10035: 2147428153 = PTR TO 10041
10036: 1 = Ctrl-A
10037: 2 = Ctrl-B
10038: 3 = Ctrl-C
10039: 4 = Ctrl-D
10040: 5 = Ctrl-E
10041: 2147428159 = PTR TO 10047
10042: 6 = Ctrl-F
10043: 7 = Ctrl-G
10044: 8 = Ctrl-H
10045: 9 = Ctrl-I
10046: 0 = Ctrl-@
10047: 2147428165 = PTR TO 10053
10048: 2147428166 = PTR TO 10054
10049: 2147428171 = PTR TO 10059
10050: 2147428176 = PTR TO 10064
10051: 2147428181 = PTR TO 10069
10052: 2147428186 = PTR TO 10074
10053: 2147428170 = PTR TO 10058
10054: 1 = Ctrl-A

10055: 0 = Ctrl-@
10056: 0 = Ctrl-@
10057: 0 = Ctrl-@
10058: 2147428175 = PTR TO 10063
10059: 0 = Ctrl-@
10060: 0 = Ctrl-@
10061: 0 = Ctrl-@
10062: 0 = Ctrl-@
10063: 2147428180 = PTR TO 10068
10064: 0 = Ctrl-@
10065: 0 = Ctrl-@
10066: 0 = Ctrl-@
10067: 0 = Ctrl-@
10068: 2147428185 = PTR TO 10073
10069: 0 = Ctrl-@
10070: 0 = Ctrl-@
10071: 0 = Ctrl-@
10072: 0 = Ctrl-@
10073: 2147428190 = PTR TO 10078
10074: 0 = Ctrl-@
10075: 0 = Ctrl-@
10076: 0 = Ctrl-@
10077: 0 = Ctrl-@
10078: 2147428192 = PTR TO 10080
10079: 0 = Ctrl-@
10080: 2147428194 = PTR TO 10082
10081: 0 = Ctrl-@
10082: 2147428196 = PTR TO 10084
10083: 0 = Ctrl-@
10084: 2147428198 = PTR TO 10086
10085: 0 = Ctrl-@

PC=503 ESP=2 FP= PTR TO 204 ASP= PTR TO 208
HP= PTR TO 10086 HMAX= PTR TO 15000

Total number of instructions executed: 23172
Last instruction to be executed:    502:    PUSHNUM 1000

Expression evaluation stack:
EXPRSTACK[1]: 1000
EXPRSTACK[0]: 742

Problem Statement 2 Relating to VM Dump Analysis

Below are questions regarding a TinyJ VM dump. The TinyJ program and its generated code/dump are provided below the questions.

The dump below was produced when TJasn.TJ compiled the TinyJ program on p. 2 and executed the generated code with a debugging stop after execution of 1,209,788 instructions. The sequence of input values was 4, 3, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2.

The INITSTKFRM instructions in the generated code are:

4: INITSTKFRM 7    339: INITSTKFRM 4    408: INITSTKFRM 6    509: INITSTKFRM 5

The instructions at addresses 351 – 407 in the generated code are shown on page 3.

Questions Relating to the Dump

Question 1(a)

For each method, say how many locations are allocated to local variables in its stackframes.

Answer 
main: 7; readRow: 4
transpose: 6; writeOut: 5

Question 1(b)

Write down the size of a stackframe of readRow(), transpose(), and writeOut().

Answer 
readRow: 10; transpose: 13;
writeOut: 10

Questions 2 – 8 are about the state of the TinyJ virtual machine at the time of the debugging stop after execution of 1,209,788 instructions:

Question 2

Consider the static variables mat, count, and tm. What values are stored in the following locations?

(a) count

Answer 
100

(b) mat[3][2]

Answer 
2

(c) tm[0][1][2]

Answer 
6

Question 3

Which method is being executed?

Answer 
readRow

Question 4

Which data memory locations constitute the stackframe of the executing method?

Answer 
addresses 170 through 179

Question 5

What values are stored in the stackframe locations of the formal parameters and first two local variables of the executing method?

Answer 
rowNum = -1
m = PTR TO 10059
c = 10          d = 6
i = 0           mm = PTR TO 10061

Question 6

Which method called the executing method?

Answer 
transpose

Question 7

Which method called the caller?

Answer 
main

Question 8

What are the addresses of main’s local variables layer and hhhhh?

Answer 
layer's addr is 151;
hhhhh's addr is 154

Next, suppose the debugging stop had not occurred.

Question 9

What would be the code memory addresses of the next 10 instructions to be executed (i.e., the 1,209,789th through 1,209,798th instructions to be executed)?

Answer 
383-5, then 406, then 353-8

Question 10

What output, if any, would be produced by execution of these 10 instructions?

Answer 
None

Question 11

Which data memory locations, if any, would be changed in value by execution of the 10 instructions? Name the variable(s) stored there and say what its/their value(s) is/are after execution of the 10 instructions.

Answer 
address 176, i, 1

Question 12

Write down what the PC, FP, ASP and ESP registers would contain after execution of the first 3 of the above 10 instructions.

Answer 
PC=406, FP=PTR. TO 175,
ASP=PTR. TO 180, ESP=0

Question 13

When the currently executing method activation RETURNs to its caller, what will PC, FP, and ASP be set to?

Answer 
PC=492, FP=PTR. TO 163
ASP=PTR. TO 170

Question 14

What is the code memory address of the next instruction to be executed after the execution of the 10 instructions listed in your answer to question 9?

Answer 
359

Question 15

What will be on top of EXPRSTACK after execution of the instruction in your answer to question 14?

Answer 
PTR TO 170

TinyJ Program and Dump

TinyJ Program

import java.util.Scanner;

class DumpEx2 {
    static int tm[][][] = new int[5][][];
    static int mat[][], count;
    static Scanner input = new Scanner(System.in);

    public static void main(String args[]) {
        int r[] = new int[5], c[] = new int[5], n = 1;
        int layer = -1;

        while (n == 1) {
            if (layer < 4)
                layer = layer + 1;
            else
                layer = 0;

            System.out.print("Enter number of rows: ");
            r[layer] = input.nextInt();
            System.out.print("Enter number of columns: ");
            c[layer] = input.nextInt();

            mat = new int[r[layer]][];
            tm[layer] = mat;

            int i = 0;
            while (i < r[layer]) {
                int iiiii = i;
                mat[i] = new int[c[layer]];
                readRow(i + 1, mat[i], c[layer], iiiii);
                i = i + 1;
            }

            int h = 0;
            while (h <= layer) {
                int hhhhh = h * 2;
                System.out.println("Given matrix: ");
                writeOut(r[h], c[h], tm[h]);
                System.out.println("Transposed matrix: ");
                writeOut(c[h], r[h], transpose(tm[h], r[h], c[h], hhhhh, hhhhh));
                h = h + 1;
            }

            h = 0;
            while (h <= layer) {
                i = 0;
                while (i < r[h]) {
                    int j = 0;
                    while (j < c[h]) {
                        tm[h][i][j] = tm[h][i][j] * 2;
                        System.out.print(tm[h][i][j]);
                        System.out.print(" ");
                        j = j + 1;
                    }
                    System.out.println();
                    i = i + 1;
                }
                h = h + 1;
                System.out.println("\n");
            }

            int jjjjj;

            System.out.print("\n\nType 1 to continue, 0 to quit: ");
            n = input.nextInt();
        }
    }

    static void readRow(int rowNum, int m[], int c, int d) {
        if (rowNum >= 0) {
            System.out.print("Row ");
            System.out.println(rowNum);
        }

        int i = 0;
        while (i < c) {
            if (rowNum == -1) {
                int mm[][] = new int[1][];
                writeOut(-1, 10, mm);
                i = i + 1;
            } else {
                int p, q, r;
                System.out.print("Enter value in column ");
                System.out.print(i + 1);
                System.out.print(": ");
                m[i] = input.nextInt();
                i = i + 1;
            }
        }
    }

    static int[][] transpose(int m[][], int r, int c, int p, int q) {
        int temp, k, i, m1[][] = new int[c][];

        k = 0;
        while (k < c) {
            m1[k] = new int[r];
            k = k + 1;
        }
        i = 0;
        while (i < r) {
            int j = 0;
            while (j < c) {
                m1[j][i] = m[i][j];
                int mm[] = new int[1];
                readRow(-1, mm, 10, 6);
                j = j + 1;
            }
            i = i + 1;
        }

        return m1;
    }

    static void writeOut(int rows, int cols, int matrix[][]) {
        int i = 0, tmp, tmp1;

        if (rows == -2) {
            while (i < 1000) i = i + 1;
            System.out.println(count);
            count = count + 1;
        }

        while (i < rows | rows == -1 & i < cols) {
            int j = 0;
            while (j < cols) {
                if (rows == -1) {
                    int mm[][] = new int[1][];
                    writeOut(-2, 0, mm);
                    j = j + 1;
                } else {
                    System.out.print(matrix[i][j]);
                    System.out.print(" ");
                    j = j + 1;
                }
            }
            if (rows >= 0)
                System.out.println();
            j = 1;
            i = i + j;
        }
    }
}

Generated Code

351: PUSHNUM           0
352: SAVETOADDR         
353: PUSHLOCADDR       1
354: LOADFROMADDR       
355: PUSHLOCADDR      -3
356: LOADFROMADDR       
357: LT                 
358: JUMPONFALSE     407
359: PUSHLOCADDR      -5
360: LOADFROMADDR       
361: PUSHNUM           1
362: CHANGESIGN         
363: EQ                 
364: JUMPONFALSE     386
365: PUSHLOCADDR       2
366: PUSHNUM           1
367: HEAPALLOC          
368: SAVETOADDR         
369: PUSHNUM           1
370: CHANGESIGN         

371: PASSPARAM          
372: PUSHNUM          10
373: PASSPARAM          
374: PUSHLOCADDR       2
375: LOADFROMADDR       
376: PASSPARAM          
377: CALLSTATMETHOD  509
378: NOP                
379: PUSHLOCADDR       1
380: PUSHLOCADDR       1
381: LOADFROMADDR       
382: PUSHNUM           1
383: ADD                
384: SAVETOADDR         
385: JUMP            406
386: WRITESTRING     122  143
387: PUSHLOCADDR       1
388: LOADFROMADDR       
389: PUSHNUM           1
390: ADD                

391: WRITEINT           
392: WRITESTRING     144  145
393: PUSHLOCADDR      -4
394: LOADFROMADDR       
395: PUSHLOCADDR       1
396: LOADFROMADDR       
397: ADDTOPTR           
398: READINT            
399: SAVETOADDR         
400: PUSHLOCADDR       1
401: PUSHLOCADDR       1
402: LOADFROMADDR       
403: PUSHNUM           1
404: ADD                
405: SAVETOADDR         
406: JUMP            353
407: RETURN            4

****** Debugging Stop ******

Data memory dump

Data memory dump
Data memory--addresses 0 to top of
stack, and allocated heap locations:

0: 2147428131 = PTR TO 10019
1: 1 = Ctrl-A
2: 2147428113 = PTR TO 10001
3: 69 = 'E'
4: 110 = 'n'
5: 116 = 't'
6: 101 = 'e'
7: 114 = 'r'
8: 32 = ' '
9: 110 = 'n'
10: 117 = 'u'
11: 109 = 'm'
12: 98 = 'b'
13: 101 = 'e'
14: 114 = 'r'
15: 32 = ' '
16: 111 = 'o'
17: 102 = 'f'
18: 32 = ' '
19: 114 = 'r'
20: 111 = 'o'
21: 119 = 'w'
22: 115 = 's'
23: 58 = ':'
24: 32 = ' '
25: 69 = 'E'
26: 110 = 'n'
27: 116 = 't'
28: 101 = 'e'
29: 114 = 'r'
30: 32 = ' '
31: 110 = 'n'
32: 117 = 'u'
33: 109 = 'm'
34: 98 = 'b'


35: 101 = 'e'
36: 114 = 'r'
37: 32 = ' '
38: 111 = 'o'
39: 102 = 'f'
40: 32 = ' '
41: 99 = 'c'
42: 111 = 'o'
43: 108 = 'l'
44: 117 = 'u'
45: 109 = 'm'
46: 110 = 'n'
47: 115 = 's'
48: 58 = ':'
49: 32 = ' '
50: 71 = 'G'
51: 105 = 'i'
52: 118 = 'v'
53: 101 = 'e'
54: 110 = 'n'
55: 32 = ' '
56: 109 = 'm'
57: 97 = 'a'
58: 116 = 't'
59: 114 = 'r'
60: 105 = 'i'
61: 120 = 'x'
62: 58 = ':'
63: 32 = ' '
64: 84 = 'T'
65: 114 = 'r'
66: 97 = 'a'
67: 110 = 'n'
68: 115 = 's'
69: 112 = 'p'
70: 111 = 'o'
71: 115 = 's'
72: 101 = 'e'

73: 100 = 'd'
74: 32 = ' '
75: 109 = 'm'
76: 97 = 'a'
77: 116 = 't'
78: 114 = 'r'
79: 105 = 'i'
80: 120 = 'x'
81: 58 = ':'
82: 32 = ' '
83: 68 = 'D'
84: 111 = 'o'
85: 117 = 'u'
86: 98 = 'b'
87: 108 = 'l'
88: 101 = 'e'
89: 100 = 'd'
90: 32 = ' '
91: 109 = 'm'
92: 97 = 'a'
93: 116 = 't'
94: 114 = 'r'
95: 105 = 'i'
96: 99 = 'c'
97: 101 = 'e'
98: 115 = 's'
99: 58 = ':'
100: 32 = ' '
101: 32 = ' '
102: 10 = Ctrl-J
103: 10 = Ctrl-J
104: 10 = Ctrl-J
105: 84 = 'T'
106: 121 = 'y'
107: 112 = 'p'
108: 101 = 'e'
109: 32 = ' '
110: 49 = '1'

111: 32 = ' '
112: 116 = 't'
113: 111 = 'o'
114: 32 = ' '
115: 99 = 'c'
116: 111 = 'o'
117: 110 = 'n'
118: 116 = 't'
119: 105 = 'i'
120: 110 = 'n'
121: 117 = 'u'
122: 101 = 'e'
123: 44 = ','
124: 32 = ' '
125: 48 = '0'
126: 32 = ' '
127: 116 = 't'
128: 111 = 'o'
129: 32 = ' '
130: 113 = 'q'
131: 117 = 'u'
132: 105 = 'i'
133: 116 = 't'
134: 58 = ':'
135: 32 = ' '
136: 82 = 'R'
137: 111 = 'o'
138: 119 = 'w'
139: 32 = ' '
140: 69 = 'E'
141: 110 = 'n'
142: 116 = 't'
143: 101 = 'e'
144: 114 = 'r'
145: 32 = ' '
146: 118 = 'v'
147: 97 = 'a'
148: 108 = 'l'

149: 117 = 'u'
150: 101 = 'e'
151: 32 = ' '
152: 105 = 'i'
153: 110 = 'n'
154: 32 = ' '
155: 99 = 'c'
156: 111 = 'o'
157: 108 = 'l'
158: 117 = 'u'
159: 109 = 'm'
160: 110 = 'n'
161: 32 = ' '
162: 58 = ':'
163: 32 = ' '
164: 32 = ' '
165: 2147438112 = PTR TO 20000
166: 2147428119 = PTR TO 10007
167: 2147428125 = PTR TO 10013
168: 1 = Ctrl-A
169: 0 = Ctrl-@
170: 4 = Ctrl-D
171: 0 = Ctrl-@
172: 0 = Ctrl-@
173: 5 = Ctrl-E
174: 4 = Ctrl-D
175: 2147428131 = PTR TO 10019
176: 4 = Ctrl-D
177: 5 = Ctrl-E
178: 199
179: 2147418277 = PTR TO 165
180: 5 = Ctrl-E
181: 0 = Ctrl-@
182: 2147428160 = PTR TO 10048
183: 0 = Ctrl-@
184: 2147428191 = PTR TO 10079
185: -1
186: 2147428191 = PTR TO 10079

187: 10 = Ctrl-J
188: 473
189: 2147418291 = PTR TO 179
190: 0 = Ctrl-@
191: 2147428193 = PTR TO 10081
192: -1
193: 10 = Ctrl-J
194: 2147428193 = PTR TO 10081
195: 361
196: 2147418301 = PTR TO 189
197: 0 = Ctrl-@
198: 1 = Ctrl-A
199: 2147428197 = PTR TO 10085
200: -2
201: 0 = Ctrl-@
202: 2147428197 = PTR TO 10085
203: 568
204: 2147418308 = PTR TO 196
205: 742
206: 0 = Ctrl-@
207: 0 = Ctrl-@
10000: 2147428118 = PTR TO 10006
10001: 2147428131 = PTR TO 10019
10002: 0 = Ctrl-@
10003: 0 = Ctrl-@
10004: 0 = Ctrl-@
10005: 0 = Ctrl-@
10006: 2147428124 = PTR TO 10012
10007: 4 = Ctrl-D
10008: 0 = Ctrl-@
10009: 0 = Ctrl-@
10010: 0 = Ctrl-@
10011: 0 = Ctrl-@
10012: 2147428130 = PTR TO 10018
10013: 5 = Ctrl-E
10014: 0 = Ctrl-@
10015: 0 = Ctrl-@
10016: 0 = Ctrl-@

10017: 0 = Ctrl-@
10018: 2147428135 = PTR TO 10023
10019: 2147428136 = PTR TO 10024
10020: 2147428142 = PTR TO 10030
10021: 2147428148 = PTR TO 10036
10022: 2147428154 = PTR TO 10042
10023: 2147428141 = PTR TO 10029
10024: 1 = Ctrl-A
10025: 2 = Ctrl-B
10026: 3 = Ctrl-C
10027: 4 = Ctrl-D
10028: 5 = Ctrl-E
10029: 2147428147 = PTR TO 10035
10030: 6 = Ctrl-F
10031: 7 = Ctrl-G
10032: 8 = Ctrl-H
10033: 9 = Ctrl-I
10034: 0 = Ctrl-@
10035: 2147428153 = PTR TO 10041
10036: 1 = Ctrl-A
10037: 2 = Ctrl-B
10038: 3 = Ctrl-C
10039: 4 = Ctrl-D
10040: 5 = Ctrl-E
10041: 2147428159 = PTR TO 10047
10042: 6 = Ctrl-F
10043: 7 = Ctrl-G
10044: 8 = Ctrl-H
10045: 9 = Ctrl-I
10046: 0 = Ctrl-@
10047: 2147428165 = PTR TO 10053
10048: 2147428166 = PTR TO 10054
10049: 2147428171 = PTR TO 10059
10050: 2147428176 = PTR TO 10064
10051: 2147428181 = PTR TO 10069
10052: 2147428186 = PTR TO 10074
10053: 2147428170 = PTR TO 10058
10054: 1 = Ctrl-A

10055: 0 = Ctrl-@
10056: 0 = Ctrl-@
10057: 0 = Ctrl-@
10058: 2147428175 = PTR TO 10063
10059: 0 = Ctrl-@
10060: 0 = Ctrl-@
10061: 0 = Ctrl-@
10062: 0 = Ctrl-@
10063: 2147428180 = PTR TO 10068
10064: 0 = Ctrl-@
10065: 0 = Ctrl-@
10066: 0 = Ctrl-@
10067: 0 = Ctrl-@
10068: 2147428185 = PTR TO 10073
10069: 0 = Ctrl-@
10070: 0 = Ctrl-@
10071: 0 = Ctrl-@
10072: 0 = Ctrl-@
10073: 2147428190 = PTR TO 10078
10074: 0 = Ctrl-@
10075: 0 = Ctrl-@
10076: 0 = Ctrl-@
10077: 0 = Ctrl-@
10078: 2147428192 = PTR TO 10080
10079: 0 = Ctrl-@
10080: 2147428194 = PTR TO 10082
10081: 0 = Ctrl-@
10082: 2147428196 = PTR TO 10084
10083: 0 = Ctrl-@
10084: 2147428198 = PTR TO 10086
10085: 0 = Ctrl-@

PC=383 ESP=3 FP= PTR TO 175 ASP= PTR TO 180
HP= PTR TO 10262 HMAX= PTR TO 15000

Total number of instructions executed: 1209788
Last instruction to be executed:    382:    PUSHNUM 1

Expression evaluation stack:
EXPRSTACK[2]: 1
EXPRSTACK[1]: 0
EXPRSTACK[0]: PTR TO 176