What Is Common Intermediate Language?

In computing, a common intermediate language (CIL), also called intermediate language (IL), is a higher-level language used as a portable intermediate representation (IR) of a compiled program. A CIL can be generated from different source languages, making it language-independent. It is also platform-independent since it is not specific to any particular processor or operating system. The CIL instruction set is designed to be abstract and easy to translate.

A CIL program can be interpreted or just-in-time compiled. Bytecode, a form of CIL, is popular because it is easy to translate into native code for different platforms. The Common Language Infrastructure (CLI) defines an environment for executing CIL bytecode.

CIL has the following features:

It is language-independent.

It is platform-independent.

It is easy to translate.

It is abstract.

It is safe.

It is managed.

It can be interpreted or just-in-time compiled.

CIL was introduced as part of Microsoft's .NET initiative. The .NET platform provides a language-independent environment for executing CIL bytecode. The C# and Visual Basic.NET programming languages both compile to CIL.

CIL has also been adopted by other platforms, such as the Mono project, an open-source implementation of the .NET platform.

There are many differences between common intermediate language (CIL) and common language runtime (CLR), but the most notable is that CLR is a managed runtime environment while CIL is not. Managed runtime environments provide automatic memory management and other services that help ensure the safety and correct execution of code. CIL is just a bytecode format, meaning that it is a series of instructions that can be interpreted by a CLR-compatible virtual machine. CIL does not contain any information about memory management or other safety features, so it is the responsibility of the developer to ensure that their code is safe and will not cause any problems when executed.

CLR is also able to dynamically load and execute code, whereas CIL must be compiled into a native executable before it can be run. This means that code written in CLR can be updated and changed without having to recompile the entire program. CIL also generally has a larger footprint than CLR, as the CLR-based virtual machine will already contain a lot of the code required to run CIL instructions.

Overall, CLR provides a much more managed and safe environment for code execution than CIL. CIL is still a useful format for code that needs to be portable and run on multiple platforms, but it is not as safe or easy to work with as CLR.

The performance benefits of using a common intermediate language are many and varied. Perhaps the most obvious benefit is that it allows for code reuse across different platforms. This can lead to more efficient code development, since the same code can be used on multiple platforms without having to be rewritten for each one.

Another major performance benefit is that a common intermediate language can help to improve code portability. This means that code written in one platform can be easily moved to another, without losing any of its functionality. This can be a major advantage when working with complex codebases, or when migrating code to a new platform.

Finally, a common intermediate language can help to optimize code execution. This is because the code can be optimized for a particular platform before it is compiled for that platform. This can lead to faster code execution and improved performance.