Making an analysis availble during call lowering


I want to be able to access a custom analysis pass during call lowering, but there isn’t a way to access this now and I’m not sure the least bad way to thread this information into the DAG.

I want to be able to use knowledge of the callee function to change the lowering of a call. Since AMDGPUDAGToDAGISel is ultimately a normal MachineFunction pass, I’m able to get the interprocedural analysis pass there but don’t have a way to pass this into the call lowering where it’s actually needed.

The laziest option would be to stash the pointer to the analysis in the TargetMachine and get it from there, but is probably not the best idea. Another option might be to store a pointer to the SelectionDAGISel pass in SelectionDAG, so then there’s a way to access the pass to get analysis directly. Is there another option?


With the legacy pass manager, are you planning to schedule the analysis pass manually and then use getAnalysisIfAvailable? Thanks again, Hal

I didn’t need to do anything special. addRequired/getAnalysis work.



Did you add INITIALIZE_PASS_DEPENDENCY somewhere? -Hal

Yes, the selector is ultimately a target defined, normal MachineFunction pass you can add dependencies on.


Sounds good. -Hal

Although I don’t see this in D35389/D35390. -Hal

I just added that to D35389, though it was somehow working before.