Arm Statistical Profiling Extension (SPE)

The Arm Statistical Profiling Extension (SPE) is an optional feature in Arm®v8.2 hardware that allows CPU instructions to be sampled and associated with the source code location where that instruction occurred.

Linaro MAP can use Arm SPE to list the source code lines that frequently trigger certain hardware events such as:

  • Branch mispredicts

  • Level 1 data cache (L1D) refills

  • Last level cache (LLC) misses

  • Translation lookaside buffer (TLB) walks

  • SVE partial predicate and empty predicate events

Note

Arm SPE counts attributed to a source code line are not absolute counts and should be used only in comparisons with counts for other lines from the same profile.