CS4410/6410: Compilers

Fall 2018

Contact information

Office email Office hours
Olin Shivers WVH 318 shivers@ccs Tu 3:30–4:30 & by appt
Andrew Cobb WVH 308 acobb@ccs Wed 1–2

Lectures are Tuesday and Friday, 1:35–3:15, in Shillman Hall, room 215.

Course schedule (lectures, projects, exams)

Piazza: http://piazza.com/northeastern/fall2018/cs4410

Slides for intro-to-SML lecture.


  1. Lexer (due Fri 9/21 10:00 pm)
  2. Parser (due Tue 10/9 10:00 pm)
  3. Static semantics (due Tue 10/23 10:00 pm)
  4. Frame analysis (unofficially due Tue 10/30)
  5. Translation to IR (due Tue 11/13 10:00 pm)
  6. Instruction selection (due Tue 11/20 10:00 pm)
  7. Live-variable Data-flow analyser (due Tue 11/27 10:00 pm)
  8. Register allocation (due Tue 12/4 10:00 pm)
  9. Integration (due Tue 12/11 10:00 pm)




SPIM is a simulator written by James Larus for the MIPS-II ISA, a real-world processor architecture that is a very clean RISC design.


Improved Canonicaliser

Appel provides a module of code for the Tiger-compiler project called the "canonicaliser," which lowers a program in the IR language to a form closer to machine code. This code is hard to read, as the invariants of the lowered/canonicalised form are not expressed in the type of the result form. Well, and the code isn't commented, either.

I rewrote this code using a target data type that makes the new form explicit in the type structure. It is much clearer (as well as voluminously commented). It also has a better commutativity analysis.

The code comes in two forms. The first version is exactly as described above. Then I took that, and converted the improved code to use the original IR data type for the target, producing a version that is a drop-in replacement for Appel's code.

So, read the first version but use the second.