Compilerlevel

Compilerlevel is a term sometimes used in discussions of compiler design to categorize the scope or granularity of a compilation pass. It is not a formal, universally defined standard, but a convenient shorthand for describing where in the compilation pipeline a transformation occurs and how much of the source language semantics it assumes or preserves.

High-level, or source-level, compilerlevel refers to passes that operate close to the language syntax and semantics. These passes typically involve parsing, semantic analysis, type checking, and desugaring, as well as transformations that modify the abstract syntax tree (AST) or high-level intermediate representations while preserving overall program meaning. Examples include language-level inlining decisions or high-level desugaring.

Mid-level compilerlevel encompasses transformations on intermediate representations that abstract away from concrete syntax but remain portable across target architectures. These passes often use forms like SSA ( Static Single Assignment) and perform optimizations such as constant folding, dead code elimination, and loop optimizations. This level is where most portable optimizations occur in modern compilers, and where a single IR can support multiple backends.

Low-level, or backend, compilerlevel involves lowering to target-specific machine code and performing architecture-oriented tasks. Passes at this level include register allocation, instruction scheduling, instruction selection, and calling convention handling. These transformations are tightly tied to the target ISA and platform, and they determine the final performance characteristics of the generated code.

The concept of compilerlevel helps frame trade-offs among portability, optimization power, and debugging complexity. While not a formal metric, it aids discussions about where and how a compiler applies transformations. Related topics include compilers, intermediate representations, backends, and compiler pipelines.