1. Single-Pass Compilers:
- These compilers process the source code only once.
- During this single pass, the compiler performs all the necessary tasks like lexical analysis, syntax analysis, semantic analysis, intermediate code generation, and code optimization (if applicable).
- Single-pass compilers are generally simpler and faster compared to multi-pass compilers, making them suitable for smaller or less complex projects.
- However, they may be less efficient in terms of code optimization as they cannot rely on information gathered from later stages during earlier parts of the compilation process.
2. Multi-Pass Compilers:
- These compilers process the source code in multiple stages, also known as passes.
- Each pass focuses on a specific task, such as lexical analysis, syntax analysis, semantic analysis, intermediate code generation, and code optimization.
- The output of one pass becomes the input for the next pass, allowing for more efficient optimization as information from later stages can be used in earlier stages.
- Multi-pass compilers tend to be more complex but offer better performance and code quality compared to single-pass compilers, making them ideal for larger and more complex projects.
Here's a table summarizing the key differences between single-pass and multi-pass compilers:
| Feature | Single-Pass Compiler | Multi-Pass Compiler |
|---|---|---|
| Number of Passes | One | Multiple |
| Processing Style | Sequential | Staged |
| Advantages | Simple, faster | More efficient, better quality |
| Disadvantages | Less efficient optimization | Complex |
| Suitable for | Smaller projects | Larger projects |