Intel Threading Building Blocks

Comparison with OpenMP

Along with Intel Threading Building Blocks, another promising abstraction for C++ programmers is OpenMP. The most successful parallel extension to date, OpenMP is a language extension consisting of pragmas, routines, and environment variables for Fortran and C programs. OpenMP helps users express a parallel program and helps the compiler generate a program reflecting the programmer’s wishes. These directives are important advances that address the limitations of the Fortran and C languages, which generally prevent a compiler from automatically detecting parallelism in code.

The OpenMP standard was first released in 1997. By 2006, virtually all compilers had some level of support for OpenMP. The maturity of implementations varies, but they are widespread enough to be viewed as a natural companion of Fortran and C languages, and they can be counted upon when programming on any platform.

When considering it for C programs, OpenMP has been referred to as “excellent for Fortran-style code written in C.” That is not an unreasonable description of OpenMP since it focuses on loop structures and C code. OpenMP offers nothing specific for C++. The loop structures are the same loop nests that were developed for vector supercomputers—an earlier generation of parallel processors that performed tremendous amounts of computational work in very tight nests of loops and were programmed largely in Fortran. Transforming those loop nests into parallel code could be very rewarding ...