Enabling the Opcode Matching Filter

The VTune(TM) Performance Analyzer enables you to limit the sampling data collection to collecting events only when specific instruction types occur. To specify the required instruction type, use the opcode matching filter. The opcode filter specifies instruction opcode or class of opcodes used to constrain a performance monitoring event. When collecting sampling data, the VTune analyzer increments the specified event only on instructions that match the filter. This feature reduces the list of collected data and displays the data collected during the specified opcode match.

To specify the opcode filter from GUI:

1. Double-click the Activity in the Tuning Browser.
   The About to Modify Activity with Results dialog box opens.

2. Specify which Activity you want to modify and Click the OK button.
   The Activity Configuration dialog box opens with the General panel active.

3. Click Configure... under the Collector(s) list.
   The Configure Sampling dialog box opens.

4. From the Configure Sampling dialog box, select the Events configuration panel.

5. In the Events panel, select the required event and click Edit event....
   The Edit Event dialog box opens.

6. Select the opcode filter from the drop-down list.

7. Click the OK button.

To specify the opcode filter from the command line:

use the -opcode-filter option.

Command-line example:

>vtl activity -c sampling -o "-ec -event-name='L3_REFERENCES' -opcode-filter='fploads'" run

This example creates the Activity with the sampling collector. The sampling collector uses the event-based sampling and collects samples based on the L3_REFERENCES event. The L3_REFERENCES event is collected only when the fploads instructions occur.

note

• The opcode matching is supported on Itanium(R)-based systems only.

• Update the Event name field in the Edit Event dialog box to assign an alias name to the event and reflect the event collection specifics. For example, for the L3_REFERENCES event with the fpload opcode filter set up, use the L3_REFERENCES_fpload name. The VTune analyzer will display this name in the Tuning Browser and apply it to sampling data views.
  To assign an alias name from the command line, use the -event-alias (or -ea) option.

• If you set up an opcode filter when configuring the event collection, the VTune analyzer uses the alias name EventName_OpcodeFilter by default. You may edit the event name in the Event name field.