About the compiler

The Open XL C/C++ for z/OS® compiler fully incorporates the LLVM and Clang compiler infrastructure to combine IBM's strength in compiler optimization technology with the LLVM open source infrastructure. LLVM is an open source compilation technology framework that is actively maintained by a large development community, supporting multiple architectures and programming languages. Clang is a part of the LLVM compiler infrastructure that provides a C and C++ language front-end and tooling infrastructure for the LLVM project.

IBM is an active participant and supporter of the LLVM open source project, contributing code for z/OS in the areas of code generation, hardware usage as well as portability and usability enhancements.

The compiler supports up to C17/C18 and C++20 language standard features, simplifying porting applications across platforms containing new C and C++ standard language features.

The compiler supports z/OS UNIX System Services and z/OS batch under 32-bit non-XPLINK, 32-bit XPLINK, and 64-bit XPLINK compilation modes, making it ideal for existing z/OS applications and porting applications from distributed platforms.