Three Address Code (3AC)

NyxLang lowers AST into an intermediate representation defined in 3ac.zig.

Why 3AC?

3AC makes complex AST expressions explicit and linear:

• temporaries store intermediate values
• control flow is explicit via labels/branches
• easier backend lowering than a tree AST

Typical instruction shapes

Even if the exact representation differs, most 3AC IRs include:

• t = op a b (binary)
• t = op a (unary)
• t = load addr
• store value -> addr
• goto L
• if cond goto L
• L: labels
• call f(args...)
• return value

Control flow lowering

• if/else becomes conditional branches + join label
• loops become header/body/exit labels with back-edges

Conventions

Document the conventions your backend expects, e.g.:

• is x = y a move?
• are booleans 0/1?
• how are comparisons represented?