Developer Guide and Reference

Contents

Guided Auto Parallelism Messages

The Guided Auto Parallelism (GAP) messages provide advice that should improve optimizations.
The messages provide suggestions for:
  • Automatic parallelization of loop nests
  • Automatic vectorization of inner loops
  • Data transformation
You must decide whether to follow a particular suggestion. For example, if the advice is to apply a particular
pragma
, you must understand the semantics of the
pragma
and carefully consider whether it can be safely applied to the loop (or loop nest) in question.
If you apply the
pragma
improperly, the compiler may generate incorrect code, causing the application to execute incorrectly.
If you do not fully understand the suggested advice, please refer to the relevant topics in the compiler documentation before applying that advice.
Once you apply the suggested advice, the compiler assumes that it is correct and it does not perform any checks or issue any warnings.
In general, messages that relate to loops tend to target vectorization and/or parallelization of loops. If you are not familiar with loop optimizations, please refer to the compiler documentation on this kind of optimization.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804