SDSCC/SDS++ Performance Estimation Flow Options

A full bitstream compile can take much more time than a software compile, sosdsccprovides performance estimation options to compute the estimated run-time improvement for a set of hardware function calls. In the SDSoC environment Project Overview window, invoke the estimator by clicking onEstimate Performance, which enables performance estimation for the current build configuration and builds the project.

Estimating the speed-up is a two phase process. First, the SDSoC environment compiles the hardware functions and generates the system. Instead of synthesizing the system to bitstream,sdscccomputes an estimate of the performance based on estimated latencies for the hardware functions and data transfer time estimates for the callers of hardware functions. In the generated Performance report, selectClick Hereto run an instrumented version of the software on the target to determine a performance baseline and the performance estimate (seeIntroductionfor more information).

You can also generate a performance estimate from the command line. As a first pass to gather data about software runtime, you use the-perf-funcsoption to specify functions to profile and-perf-rootto specify the root function encompassing calls to the profiled functions. Thesdscccompiler then automatically instruments these functions to collect run-time data when the application is run on a board. When you run an "instrumented" application on the target, the program creates a file on the SD card calledswdata.xml, which contains the run-time performance data for the run.

Copyswdata.xmlto the host and run a build that estimates the performance gain on a per hardware function caller basis and for the top-level function specified by the–perf-rootfunction in the first pass run. Use the–perf-estoption to specifyswdata.xmlas input data for this build.

The following table specifies thesdsccoptions normally used to build an application.