THis is what the P4 manual says:
"The RDTSC instruction is not a serializing instruction. Thus, it does
not necessarily wait until all previous instructions have been executed
before reading the counter. Similarly, subsequent instructions may begin
execution before the read operation is performed."
Thus it *shouldn't* sync the pipeline. cpuid is a serializing inst, yes.
TJ
-- _________________________________________________________________________Terje Eggestad mailto:terje.eggestad@scali.no Scali Scalable Linux Systems http://www.scali.com
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