Intel® VTune™ Profiler User Guide

User Guide

  • 2020
  • 06/18/2020
  • Public Content
Contents

Flags Merge Stalls

Metric Description

Some instructions have increased latency on Intel microarchitecture code name Sandy Bridge. Shift cl operations require a potentially expensive flag merge. This metric estimates the performance penalty of that merge.

Possible Issues

A significant proportion of cycles were spent handling flags merge operations. Use the source view to discover the responsible instructions and try to avoid their use.

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