Program data objects include constants, variables, arrays and aggregates such as structures and unions defined in the program source code, along with distinct aggregate elements. The Performance Analyzer relates performance metrics to program data objects individually and as aggregates.
Some synthetic data objects are also defined as described in the following table.
Data object | Description | |
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<Total> | Sum of all data objects, represents the program data as a whole. | |
<Scalars> | Sum of all scalar constant and variable data objects. | |
<Unknown> | Collects all events for which the data object cannot be found. | |
(Unascertainable) | Referenced from a compilation object without hardware counter profiling support, or in an experiment without apropose backtracking during collection. | |
(Unverifiable) | Hardware counter profiling support insufficient to verify apropos backtracking. | |
(Unresolvable) | Not resolvable due to encountering a control transfer target during backtracking. | |
(Unspecified) | Not specified by the compiler as a memory-referencing instruction. | |
(Unidentified) | No identifying descriptor provided by the compiler. | |
(Undetermined) | Not determined from the symbolic information provided by the compiler. | |
(Anon) | Space between specified data objects in aggregates. |
The Performance Analyzer tabs can show a rankable list of program data objects or data object layouts annotated with data-derived metrics.
When a program data object is selected in either of the tabs, its metrics and other information are displayed in the Summary tab.
Data-derived metrics come from hardware counter events for memory operations collected with apropos backtracking enabled for compilation objects built with associated hardware profiling support. The metrics initially shown are based on the data collected and the data presentation settings for inclusive and exclusive (code) metrics.
Data-derived metrics apply only to data objects, and are similar to inclusive (code) metrics: the metric value for an element of an aggregate is also included in the metric value for the aggregate.
See also | |
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The DataLayout Tab The DataObjects Tab The Summary Tab |