Comparing Experiments

You can load multiple experiments or experiment groups simultaneously in the Analyzer. By default, when multiple experiments on the same executable are loaded, the data is aggregated and presented as if it were one experiment. You can also look at the data separately, so you can compare the data in the experiments.

To compare two experiments in the Analyzer, you can open the first experiment in the normal way, and then select File > Add Experiment to load the second experiment. To compare them, right-click in a tab that supports comparing and select Enable Experiment Comparison.

The tabs that support comparing experiments are Functions, Callers-Callees, Source, Disassembly, Lines, and PCs. In comparison mode, the data from the experiments or groups is shown in adjacent columns on these tabs. The columns are shown in the order of the loading of the experiments or groups, with an additional header line giving the experiment or group name.

Enabling Comparison Mode By Default

You can enable comparison mode by default by setting compare on in your .er.rc file. Alternatively, you can enable comparison mode in the Analyzer's Set Data Presentation dialog by selecting the Compare Experiments option in the Formats tab. To make this the default, click the Save button to add compare on to your .er.rc file.

You can also compare experiments using the er_print compare command. See compare { on | off } for more information.