3 ms·
I'm still upset about the permanent-until-vzeroupper "transition" penalty on nonVEX instructions on skylake after any VEX instruction.
by twtw 8y ago
I'm still upset about the permanent-until-vzeroupper "transition" penalty on nonVEX instructions on skylake after any VEX instruction.
- chrisseaton 8y agoDo you know anything about that? I know some ABIs have a vzeroupper at the end of every method - what is this for and do you know how expensive is is?
- haberman 8y agoLooks to be a complicated issue, with very different performance profiles across different microarchitectures: https://software.intel.com/en-us/forums/intel-isa-extensions/topic/704023 https://software.intel.com/en-us/forums/intel-isa-extensions...