[chrisseaton]

> There are different implementations for it doing different things.

And are they now speculative? They weren't for the first 15 years or so.

[lewurm]

CoreCLR started to implemented Tiered Compilation https://github.com/dotnet/coreclr/blob/master/Documentation/...

It's experimental currently, no profile guided optimizations _yet_

[pjmlp]

.NET Framework supports PGO since .NET 4.5.