User Guide

Contents

Finding a Critical Path

The
critical path
from a node N to a node M is the longest (in time) path from N to M. Its length is a lower-bound on the execution time of a compuation that begins at N and ends at M.
The
Critical Path Analytic
in the Flow Graph Analyzer computes a critical path for each source node/sink node pair. A given graph has as many critical paths as the product of the number of source nodes and the number of sink nodes. Source nodes are the nodes in the graph without any predecessors, or nodes with an in-degree of zero. Sink nodes are the nodes in the graph without any successors, or nodes with an out-degree of zero.
Click the
Compute Critical Path
icon on the toolbar to calculate the critical paths in the graph. These critical paths are displayed in descending order by cost. Inspect the topmost critical path first because, as the longest critical path, it sets the lower bound on the execution time for the whole graph.
The screenshot below shows a sample critical path report.
sample critical path report
Selecting a critical path in the
Analytics Report
window highlights all the nodes on the critical path.

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