According to https://plus.google.com/+jwildeboer/posts/jj6a9JUaovP https://plus.google.com/+jwildeboer/posts/jj6a9JUaovP Google was deploying a retpoline-based

According to https://plus.google.com/+jwildeboer/posts/jj6a9JUaovP https://plus.google.com/+jwildeboer/posts/jj6a9JUaovP Google was deploying a retpoline-based mitigation in production in September. Seems likely that existed _before_ any thought of microcode fixes. I wonder if, based on working with Skylake and newer chips only at the time, Intel thought the microcode version was going to be a performance alternative to retpoline instead of it being the other way around.