CS611
Programming Assignment 4
Fall 1998

Implement in C a virtual machine to implement the mythical sim611 machine.

You will do this by implementing the function "Exec" in the file exec.c in the code distributed in the directory ~cs611/public/prog4/sim611. Code is provided to read a sim611 object file and to call the "Exec" function once the program is loaded in memory.

Points will be awarded for each test file successfully passed. Grading of a test file will be "pass/fail". That is, no partial credit will be assigned for a given test file. Either the file is processed completely correctly or it isn't.

There are eight test files in ~cs611/public/prog4:

• test0.asm (50 points): tests the CLR, INC, DEC and HALT instructions. This test file must be completed first.

• test1.asm (10 points): tests the branch and compare instructions.

• test2.asm (10 points): tests the load and store instructions.

• test3.asm (10 points): tests the arithmetic and bitwise instructions.

• test4.asm (5 points): tests the setting of the condition codes by non-compare instructions. This test requires test1.asm and test3.asm (as well as test0.asm) to be completed first.

• test5.asm (5 points): tests the call/return and push/pop instructions.

• test6.asm (10 points): tests the "special" instructions and exceptions. Should only be attempted after test[0-5].asm have been successfully handled.

• fact.asm (10 points; i.e. bonus points): the factorial program.

Your programs will be graded using an Alpha machine (e.g. alberti) so be sure to test in that environment.

A solution to this assignment is available for execution on an Alpha as ~cs611/bin/sim611. The as611 assembler is also available for the Alpha as as ~cs611/bin/as611. You should be able to develop your solution on any machine. Object files can be built on an Alpha and then transferred to another machine for execution.

Your programs should be submitted for grading from either alberti, hopper, or christa. To turn in this assignment, type:

~cs611/bin/submit prog4 exec.c

Notes:

• Do not turn in any other files.

• In particular, do not turn in any non-Ascii files (i.e. no object files, no executable files, etc.).

Submissions can be checked by typing:

~cs611/bin/scheck prog4

To receive full credit for the assignment, you must turn in your files prior to 8am on Monday November 2. Late submissions will be accepted at the penalty of 5% per day up to one week late.

Remember: as always you are expected to do your own work on this assignment.

Comments and questions should be directed to pjh@cs.unh.edu