The PAPI library names a number of predefined, or preset events. This set is a collection of events typically found in many CPUs that provide performance counters. A PAPI preset event name is mapped onto one or more of the countable native events on each hardware platform. On any particular platform, the preset can either be directly available as a single counter, derived using a combination of counters or unavailable.
The PAPI preset events can be broken loosely into several categories, as shown in the table below: PAPI Preset Event Definitions by Category:
Floating Point Operations:
The exact semantics of an event counter are platform dependent. PAPI preset names are mapped onto available events in a way so as to count as similar types of events as possible on different platforms. Due to hardware implementation differences it is not necessarily possible to directly compare the counts of a particular PAPI event obtained on different hardware platforms.
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