[PATCH] D136999: [AArch64] Lower READCYCLECOUNTER using MRS CNTVCT_EL0

[Dave Green via Phabricator via llvm-commits]

dmgreen added a comment.

Hello. I gave the two registers a look and CNTVCT_EL0 seemed to work better than PMCCNTR_EL0 on the systems I tried. The existing PMCCNTR_EL0 would run into illegal instruction exceptions.

This was added by @ab though and I only tried linux/android. It would be good to hear from them about whether changing this is OK for their platform.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136999/new/

https://reviews.llvm.org/D136999