COS 320: Compiling Techniques, Spring 2026

Course information

Semester: Spring 2026
Lectures: Tuesday & Thursday 1:20pm - 2:40pm
Location: Briger Hall Room A102
Instructor: Zak Kincaid, zkincaid@cs.princeton.edu.
Teaching assistant: Vivienne Goyal
Office hours:

Zak: 3:30pm Monday, 194 Nassau Room 230
Vivienne: 10am Wednesday & Friday Friend 010

Links: Canvas, Ed, Gradescope, Real world OCaml, OCaml manual, OCaml standard library, OCaml style guide.

Description

Understand the design and construction of compilers. Concepts include syntax analysis, semantics, code generation, optimization and run-time systems. Translation of imperative languages (such as C), functional languages (such as ML), and object-oriented languages (such as Java) will be studied. Students will implement a complete compiler for a small language.

Many of the course materials and assignments have been adapted from Steve Zdancewic's CIS 5521 at U Penn.

Schedule

Materials below the dotted red line have not yet been updated for Spring 2026.
The (optional) readings are from Andrew W. Appel's Modern Compiler Implementation in ML.

Date	Topics	Readings
Jan 27	Introduction (OCaml slides)	Appel 1
Jan 29	X86lite	Appel 6

Feb 3	Intermediate representations I (example code)
Feb 5	Intermediate representations II (example code)	Appel 8
Feb 10	LLVM I
Feb 12	LLVM II
Feb 17	Lexing (example code)	Appel 2
Feb 19	Parsing I (example code)	Appel 3
Feb 24	Parsing II (web demo, example code)
Feb 26	Parsing III (web demo)
Mar 3	Midterm review
Mar 5	Midterm
Mar 10,12	Spring break
Mar 17	Types I (example code)
Mar 19	Types II
Mar 24	Types III
Mar 26	Data Flow Analysis & Optimization I	Appel 17
Mar 31	Data Flow Analysis & Optimization II (web demo)
Apr 2	Data Flow Analysis & Optimization III
Apr 7	Register Allocation	Appel 10
Apr 9	Control flow (web demo)
Apr 14	Loop Optimizations	Appel 18
Apr 16	High-level languages I (example code)	Appel 13,14,15
Apr 21	High-level languages II
Apr 23	Wrap-up

Assignments

There are five OCaml programming assignments in the course, which we recommmend you complete with a partner. Through these assignments you will gradually build a compiler for a small programming language. These assignments are time consuming so it would be wise to start early. Instructions for obtaining, completing, and submitting homework assignments can be found here.

Grading policies

There will be five assignments during the semester, along with a midterm and a final. Your final grade will be weighted as follows:

Component	Date	Weight
HW1: x86lite	Monday February 9, 11:00pm	10%
HW2: LLVMlite	Monday February 23, 11:00pm	12%
HW3: Compiling Oat v.1	Monday March 23, 11:00pm	13%
HW4: Compiling Oat v.2	Monday April 13, 11:00pm	13%
HW5: Dataflow Analysis and Register Allocation	Tuesday May 5, 5:00pm (Dean's date)	12%
Midterm Exam	Thursday March 5 (in class)	20%
Final Exam	TBD	20%

Late policy

Assignments are due at 11pm, with a 1 hour grace period.
Each assignment can be submitted a maximum of four days late. Late assignments will be penalized 10% per day late. Penalties for up to four late days (across all assignments) are waived. If a student uses more than four late days, late passes will be applied to late work in weight order.
In case of special circumstances (e.g., illness, religious holidays, etc.), please write to zkincaid@cs.princeton.edu if you need an extension.

Conduct

For homework and assignments, discussions with others are permitted, where the goal is to aid your understanding. You may similarly make use of large language models (LLMs) like ChatGPT---for conceptual help only. However, the submitted work/code should be entirely your own (and your partner, should you work in a pair).
Do not copy another person's program, or get solutions from resources outside the course.
If you have any questions or concerns, please discuss these policies with the instructors.
Conduct during exams is covered by the University Honor Code.