Assignment 05 - microIR to miniRA Translator

This assignment is graded out of 15: 9 for this take-home part and 6 for an extension you implement in the lab session on 27/10/2026. See the assignments page for how the lab component works.

This assignment is the fifth part of a multi part project to write an optimizing compiler for Minijava. In this assignment, we start with programs in microIR format and translate them to miniRA. Register Allocation must be carried out using the Linear Scan algorithm.

Use JTB and JavaCC and write in Java one or more visitors which translate MicroIR programs to MiniRA form. Your main file should be called P4.java, if A.microIR contains a program to be register allocated then

$ javac P4.java
$ java P4 < A.microIR > A.miniRA

should create A.miniRA in miniRA form and is semantically equivalent to A.microIR. Note, your program must take input from standard input and write to standard output (so that we can use redirection).

To check that a program is in miniRA form, you could tie the miniRA.jj to build a parser. To ensure that your miniRA program is semantically equivalent to the microIR program, you can use the interpreter of miniRA interp-miniRA.jar to compare the output of A.microIR with the output of the miniRA program generated by your register allocator; say the generated miniRA code is stored in A.miniRA, then to invoke the interpreter use: java -jar interp-miniRA.jar < A.miniRA

Alternatively, make compiles the assignment, make run FILE=<input> runs it, and make clean removes the .class files you must delete before submitting.

Note: Please do not alter the directory structure of RollNo_P4. Only edit GJDepthFirst.java and P4.java

Resources

The source files are on Github.

Get the source by cloning the entire repo:

$ git clone https://github.com/fplaunchpad/cs3300_m26

If you have already cloned the repo, you can get the latest updates by:

$ cd cs3300_m26 # go to the cloned repo
$ git pull

The microIR grammar specification is BNF-microIR.

The miniRA grammar specification is BNF-miniRA.

Submission

Rename the folder RollNo_P4 with your roll number. For example, if your roll number is cs99b999, then the folder should be named cs99b999_P4. Remove all the .class files before submission. For example, you can do:

$ cd cs99b999_P4
$ find . -name "*.class" | xargs rm

Then produce the compressed gzip archive as follows:

$ tar cvzf cs99b999_P4.tar.gz cs99b999_P4

Submit the .tar.gz file.

Note: You should thoroughly test your code. Some sample mini java programs are provided for testing. Create positive and negative tests per feature and test your code before submission. Please ensure that there are no compilation errors. If there are compilation errors, that code will yield zero marks.

Checking your work before you submit

Run the same program that marks you over the public testcases:

$ python3 ../selftest/eval.py <YOUR-ROLLNO>_P4.tar.gz

It builds your archive the way the grader does, so a packaging mistake shows up here instead of costing you marks. Note that assignment 5 submits as _P4, one behind the assignment number.

There are three sets of testcases: the public set you can run here, a private set behind the online checker that reports only how many passed, and a hidden set used for marking that you never see. You are marked on all three together, every test counting equally, so passing the first two is necessary and not sufficient. A submission that does not build scores zero.

See selftest/README.md.