CS 5363: Compiler Project, Part #3

Submission Deadlines:

First Draft: 5pm, October 18, 2005
Graded Submission: 5pm, November 1, 2005

Project Overview

In this class, you will be writing an optimizing compiler for a toy programming language, which we will call, TL05 (and targeting the SPIM MIPS Simulator.)

You may choose C, C++, or Java to implement your compiler, but it must compile and run on the machines in the Computer Science Department's Linux lab. (If you choose C or C++, you will also need to create a makefile that will build an executable from your source files.) The entire compiler must be your own, independent work, and each assignment will build on the work of the previous assignments.

Third Assignment

The third assignment is to complete the compiler front-end by adding an additional phase that translates your TL05 Abstract Syntax Tree into basic blocks of three-address code instructions (Section 5.4.2 of your textbook) with he following properties:

Each basic block ends in a conditional or unconditional branch (a.k.a., jump). (As in your textbook.)
The instructions are in Static Single Assignment Form. (i.e., there is only one instruction that assigns to each IR variable, and φ-functions are used to alternative original program variable definitions reaching join nodes. (See Section 5.5 of your textbook.)

In addition, you should provide a mechanism to output the control flow graph (with the nodes corresponding to basic blocks and labeled with the appropriate IR instructions).

It is recommended, that...

... you base your three-address code on ILOC. (C.f., Appendix A of your textbook.)
... you get the CFG output working as early as possible to aid in your debugging.
... you represent instructions with quadruples and connect the instructions within a basic block using a linked list. (C.f. Section 5.4.3 of your text book.)
... you use Brandis and Mössenböck's Single-Pass SSA Generation algorithm in conjunction with a tree-walk approach to code generation (c.f., Section 7.3.1 of your text book). But it is also permissible to first generate non-SSA three-address code and then use another SSA-generation algorithm, such as Aycock and Horspool's, or the one on Section 9.3 of your text book. (If you're really adventurous, there's a new SSA generation algorithm that was just published in the May issue of TOPLAS.)
... you implement support for arrays after you've completed and tested everything else. Array accesses and updates should be expanded to actual memory accesses (see section 7.5). The single-assignment property of SSA should apply to the temporaries involved in the address computations, but it is not necessary that it apply to the individual array-elements.

You may find it useful to refer to the new informal semantics of the TL05 language.

Deliverables and Submission

When you have completed your assignment, you should create a tar archive or zip file containing your source files (with the correct package-based directory structure if you're using Java), the makefile (if your compiler is in C or C++), and your test cases. These should be attached to an email to vonronne@cs.utsa.edu. The subject of this email should containing the text "CS 5363 Submission #3", and the body should contain a "cover letter". This "cover letter" must contain:

Your name.
A statement that the attached source files are your own work.
A statement of approximately how many hours it took to complete the assignment.
Instructions for compiling and running your submission.
A description of any known limitations of the implementation being turned in (e.g., incomplete features, test cases that don't run)
A list of deficiencies that were in the parser, type checker, etc. when part #2 was submitted, but our now fixed.
Anything else you think I should know while grading your assignment

Grading Criteria

This assignment has two due dates. You are required to turn in the current state of your compiler by the first due date, at which time you will be given suggestions for further improvements. Your first submission will not, however, be graded until the second deadline. If you wish to implement optimizations in your compiler (which will be extra credit), you should attempt to finish this part by the first due date.

As a matter of policy, late work will not be accepted. Partially completed assignments will, however, be evaluated for partial credit. This assignment depends on the parser working correctly, so the correctness or incorrectness of the scanner/parser may be considered when grading this assignment. Projects will be evaluated using a rubric similar to the following:

75% - implementation
- 15% - data structure design
- 20% - code generation for statements
- 20% - code generation for expressions
- 20% - SSA generation
10% - output
10% - quality of test cases
5% - cover letter

In addition, extra credit will be given for deficiencies in the parser and type checker that have been remedied, since part #2 was turned in. A penalty of up to 50% may be deducted if the program doesn't compile and run on the machines in the department's Linux lab.

Errata

There may need to be corrections, clarifications, or other modifications to these instructions, you are responsible for monitoring the class web site, monitoring your CS account mailboxes, and listening during lecture for announcements related to this assignment.