[PATCH] D49310: [llvm-mca][BtVer2] Teach how to identify dependency-breaking idioms.

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

In https://reviews.llvm.org/D49310#1162868, @andreadb wrote:

> In https://reviews.llvm.org/D49310#1162667, @lebedev.ri wrote:
>
> > Can you add a comment to the end of the btver sched profile, that `X86MCInstrAnalysis::isDependencyBreaking()`
> >  is also responsible (as in, needs to be modified) in detection of dep-breaking patterns?
>
>
> If the goal is to document this behavior, a comment in the class MCInstrAnalysis should be enough.
>  If the goal is to provide guidelines for people that want to use llvm-mca, then we should have all this features documented in a .rst file.


The goal is to spare time of whoever will be adding some new scheduling model by explaining that the `X86MCInstrAnalysis::isDependencyBreaking()` needs to be modified too, for mca to be able to properly handle these dependency-breaking idioms.

> In the next future (realistically by the end of august), with the help of Matt, there is a plan improve the llvm-mca documentation. We would describe all the changes that would help improving the analysis in llvm-mca.




https://reviews.llvm.org/D49310