[llvm] [MISched] Add statistics to quantify scheduling (PR #138090)

[Cullen Rhodes via llvm-commits]

c-rhodes wrote:

> > > A question about how this works - If you start with `A;B;C;D;E` and reorder it to `A;E;B;C;D`, does only 1 node count as in-order, or do 4? Is 4 nodes being inorder covered by #137981 (at least if they pick NodeOrder to remain in-order).
> > 
> > 
> > 1, I fail to see how it could be 4, only A is in source order there?
> 
> I was wondering what the definition of inorder was it was using. Another example like `A;E;C;D;B` would have 3 nodes 'inorder' IIUC (even though it is more out-of-order than the first example)? To me moving one node in `A;E;B;C;D` would be a small change and most nodes remain inorder except for it.

that's a fair point, this is simply "does the index of the instruction change after scheduling?" 



https://github.com/llvm/llvm-project/pull/138090