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Supercharge Your IT Environment

IBM compilers for AIX and Linux can significantly improve performance

Computer architectures designed with high-performance microprocessors are reshaping the IT landscape. Today’s software developers must deliver products and services faster with higher quality and performance to stay competitive, but in an environment with unprecedented performance potential, it’s increasingly difficult for application developers to simultaneously handle business logic and performance issues in their code.

That’s where IBM Power Systems* technology steps in, says Susan Yoskin, IBM Rational* marketing solution manager. “Power Systems servers are based on modern, high-performance POWER7* processors,” she says. “They offer outstanding performance, superior economics and breakthrough energy efficiency.”

Compiler developers play an active role in new processor development, working closely with hardware developers and researchers from initial concept to delivery of new Power Architecture*. During this process, C/C++ compiler prototypes are used to validate both functional and performance objectives of new processor architectures. IBM compilers are also designed to improve programmer productivity, lowering the skill level required to create and maintain high-performance applications.

According to Roland Koo, product manager for IBM compilers, “State-of-the-art compilation technology enables programmers to exploit leading-edge performance of new hardware without source-code changes. Developers only need to focus on the logic of the applications and let the compiler figure out the best way to transform and optimize the code to run on target Power Systems.”


Maintain and Extend Business Applications

These compiler products can be used to develop and maintain business-critical applications on Power Systems running AIX* and Linux*:
→XL C/C++
→XL Fortran

→XL C/C++
→XL Fortran

The emergence of service-oriented architecture (SOA) enables developers to methodologically modernize existing applications and integrate them with new applications running on modern Web-based infrastructures. COBOL for AIX and PL/I for AIX compilers also enable developers to extend existing business-critical applications to interoperate with Java*, process inbound and outbound XML documents, and work with Web services.

Applications developed with XL C/C++, COBOL, PL/I and Java can interoperate on AIX. Applications developed with XL C/C++, and XL Fortran can interoperate on both AIX and Linux. These capabilities provide application programmers with the flexibility to take advantage of the strengths of different programming languages within a single application.


Industry-Leading Optimization Technology

“IBM compilers, XL C/C++ for AIX and Linux, XL Fortran for AIX and Linux, COBOL for AIX and PL/I for AIX share a common optimizing back-end technology that’s specifically designed to take full advantage of all advanced hardware features of the Power* processor,” Koo says. This means IBM compilers can optimize the performance of commercial and high-performance computing workloads on IBM Power Systems. Developers can optimize applications for a common Power architecture, a specific Power architecture or a group of Power architectures.

XL C/C++ and XL Fortran include an additional optimizer that performs more advanced and aggressive optimizations. It’s automatically invoked at high optimization levels. This high-level optimizer has state-of-the-art technologies to perform advanced loop, whole program, profile-driven and memory hierarchy optimizations. It can also automatically parallelize and vectorize serial code to take advantage of multicore design and the vector units of the Power processor architecture.

Advanced optimization technology enabled XL C/C++ and XL Fortran to deliver record-breaking Standard Performance Evaluation Corporation (SPEC) benchmark results for the POWER7 processor. It also enabled the latest version of COBOL for AIX to deliver performance improvements of up to 15 percent compared to the previous version, Koo says.

Many IBM software products running on Power Systems servers are built with IBM compilers such as DB2* and AIX. Both use XL C/C++ for AIX and its advanced optimization technology to deliver reliable and high-performing products. IBM XL C/C++ for Linux can compile performance-critical components of Watson, the POWER7 cluster supercomputer that became a “Jeopardy!” champ.

Rice University is using a POWER7 cluster, BlueBioU, to research how to lessen the side effects of radiation treatments for cancer patients. The applications are successfully migrated and optimized by XL C/C++ for Linux and XL Fortran for Linux. This new infrastructure is giving doctors and researchers much quicker access to the information they need to advance their work. (Read more about it in “An Edge Against Cancer” at


Melanie Steckham is an information developer with IBM Rational Software.



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IBM compilers for AIX and Linux can significantly improve performance

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