Simple

A Simple showcase for the Sea-of-Nodes compiler IR

This repo is intended to demonstrate the Sea-of-Nodes compiler IR.

The Sea-of-Nodes is the core IR inside of HotSpot's C2 compiler and Google's V8 compiler and Sun/Oracle's Graal compiler.

Since we are show casing the SoN IR, the language being implemented is less important.
We're using a very simple language similar to C or Java, but with far fewer features. The Sea-of-Nodes is used for machine code generation in these industrial strength systems - but for this demonstration the backend is both difficult and less important.

This repo also is not intended to be a complete language in any sense, and so the backend will probably start with levering C or Java.

Chapters

The following is a rough plan, subject to change.

Each chapter will be self-sufficient and complete; in the sense that each chapter will fully implement a subset of the simple language, and include everything that was created in the previous chapter. Each chapter will also include a detailed commentary on relevant aspects of the Sea Of Nodes intermediate representation.

The simple language will be a small subset of C.

• Language: Simple language grammar.
• Chapter 1: Script that returns an integer literal, i.e., an empty function that takes no arguments and returns a single integer value. The return statement.
• Chapter 2: Simple binary arithmetic such as addition, subtraction, multiplication, division with constants. Peephole optimization / simple constant folding.
• Chapter 3: Graphical Visualization of Sea of Nodes IR.
• Chapter 4: Local variables, and assignment statements. Read on RHS, SSA, more peephole optimization if local is a constant.
• Chapter 5: Binary and Comparison operators involving constants and variables. Non-zero values will be truthy.
• Chapter 6: if statement. CFG construction, peephole optimization around dead control flow.
• Chapter 7: while statement.
• Chapter 8: Global Value Numbering.
• Chapter 9: Functions and calls.
• Chapter 10: Boolean operators &&, || and ! including short circuit.
• Chapter 11: float type.
• Chapter 12: Memory effects: general memory edges in SSA. Peephole optimization around load-after-store/store-after-store.
• Chapter 13: Equivalence class aliasing, fine grained peephole optimizations. Free ptr-to analysis in SoN; but does not handle aliasing in arrays.
• Chapter 14: One dimensional static length array type. Array load/store.
• Chapter 15: Global Code Motion - unwind SoN to CFG. Scheduling.
• Chapter 16: Instruction selection, BURS.
• Chapter 17: Backend register allocation.
• Chapter 18: Garbage Collection.