[PATCH] D32067: [XRay][compiler-rt] Use emulated TSC when CPU supports rdtscp, but cannot determine the CPU frequency

[Dean Michael Berris via Phabricator via llvm-commits]

dberris added a comment.

Probably want to make sure that the call-site for `probeRequiredCPUFeatures()` don't happen in the hot path (i.e. that this check is only done once).

The previous patch that attempted to fix this in FDR mode was calling `probeRequiredCPUFeatures()` in an if conditional. We should revert that and should do this check once and store the results to a function-local static bool.


https://reviews.llvm.org/D32067