Program optimization

IBM® Open XL C/C++ incorporates the LLVM compiler infrastructure, so the compiler fully supports the optimization features from LLVM. The compiler provides several compiler options that can help you control the optimization and performance of your programs.

With these options, you can perform the following tasks:

Select different levels of compiler optimizations
Control optimizations for loops, floating point, and other types of operations
Optimize a program for a particular class of machines or for a specific machine configuration, depending on where the program will run

Optimizing transformations can give your application better overall execution performance. IBM Open XL C/C++ provides a portfolio of optimizing transformations tailored to various supported hardware. These transformations offer the following benefits:

Reducing the number of instructions executed for critical operations
Restructuring generated object code to make optimal use of the Power Architecture® processors
Improving the usage of the memory subsystem

For more details, see "Clang Compiler User's Manual" in the Clang documentation.