User Guide

Contents

Enforce Offloading for Specific Loops

Model performance on a target device for specific loops only even if they are not profitable.
If you want to check offload profitability only for specific loops or if your loop of interest is reported as not recommended for offloading to an accelerator, you can model performance only for these loops.
To do this:
  1. Collect performance data using the
    collect.py
    script or the
    advisor
    command line interface. For example:
    advisor --collect=survey --project-dir=
    <project-dir>
    --stackwalk-mode=online --static-instruction-mix --
    <target-application>
    advisor --collect=tripcounts --project-dir=
    <project-dir>
    --flop --enable-cache-simulation --target-device=
    <target>
    --
    <target-application>
  2. Rerun performance modeling using the
    analyze.py
    script or the
    advisor
    command line interface with the following options:
    • --select=
      [<loop-ID1>|<file-name1>:<line1>,<loop-ID2>|<file-name2>:<line2>,...]
      (with
      advisor --collect=projection
      ) or
      --select-loops=
      [<loop-ID1>|<file-name1>:<line1>,<loop-ID2>|<file-name2>:<line2>,...]
      (with
      analyze.py
      ) to specify loop(s) of interest in a comma-separated list
    • --enforce-offloads
      to make sure all of them are offloaded
    • Optional
      :
      --set-parallel=
      [<loop-ID1>|<file-name1>:<line1>,<loop-ID2>|<file-name2>:<line2>,...]
      to ignore loop-carried dependencies when estimating offload profitability
      Make sure to specify the same loops/functions or a subset of loops/functions specified with the
      --select
      /
      --select-loops
      option.
    For example:
    advisor --collect=projection --project-dir=
    <project-dir>
    --config=
    <config>
    --select=[<file-name1>:<line-number1>,<file-name2>:<line-number2>] --enforce-offload
Open the
Offload Modeling
results in the
Intel® Advisor
GUI or view an HTML report. The results will show performance modeled for the selected loops only.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.