Is there an equivalent instruction to rdtsc in ARM?

Question

For my project I must use inline assembly instructions such as rdtsc to calculate the execution time of some C/C++ instructions.

Th

Answer 1

You should read the PMCCNTR register of a co-processor p15 (not an actual co-processor, just an entry point for CPU functions) to obtain a cycle count. Note that it is available to an unprivileged app only if:

1. Unprivileged PMCCNTR reads are alowed:

   Bit 0 of PMUSERENR register must be set to 1 (official docs)

2. PMCCNTR is actually counting cycles:

   Bit 31 of PMCNTENSET register must be set to 1 (official docs)

This is a real-world example of how it`s done.