[PATCH] D142747: [Pseudo Probe] Do not instrument EH blocks.

[Hongtao Yu via Phabricator via llvm-commits]

hoy added inline comments.


================
Comment at: llvm/include/llvm/Analysis/EHUtils.h:17
+/// Compute a list of blocks that are only reachable via EH paths.
+template <typename AccessorTraits, typename FunctionT, typename BlockT>
+static void computeEHOnlyBlocks(FunctionT &F, DenseSet<BlockT *> &EHBlocks) {
----------------
wenlei wrote:
> hoy wrote:
> > wenlei wrote:
> > > hoy wrote:
> > > > wenlei wrote:
> > > > > 1. Is the need for AccessorTraits because of the different API between MBB (member `predecessors()`) vs BB (standalone `predecessors()`)? 
> > > > > 
> > > > > 2. If we have to use AccessorTraits, can we avoid exposing it as template type at the top level API (`computeEHOnlyBlocks`)? I think we should be able to select the right traits based on BlockT. 
> > > > > 
> > > > > 3. Since we only need successor/predecessor, I'd suggest we decouple this from `afdo_detail::IRTraits`. That is, we define two small traits here for both MBB and BB.
> > > > > Is the need for AccessorTraits because of the different API between MBB (member predecessors()) vs BB (standalone predecessors())?
> > > > 
> > > > Yes. I don't see code shared between BB and MBB often. I guess that's one reason preventing it from being shared easily.
> > > > 
> > > > > If we have to use AccessorTraits, can we avoid exposing it as template type at the top level API (computeEHOnlyBlocks)? I think we should be able to select the right traits based on BlockT
> > > > 
> > > > Can you elaborate a little more? Iike based on typeid check?
> > > > 
> > > > > Since we only need successor/predecessor, I'd suggest we decouple this from afdo_detail::IRTraits. That is, we define two small traits here for both MBB and BB.
> > > > 
> > > > Makes sense.
> > > > 
> > > > Can you elaborate a little more? Iike based on typeid check? 
> > > 
> > > I haven't looked at how. But I suppose with some investigation we should be able to find a way to hide the traits from API. We have precedence - there's not any need for specifying the traits when instantiating a sample loader. 
> > Actually just figured out that there are predecessors/successors API defined for MBB in MachineSSAContext.h. We can use that and `AccessorTraits` will not be needed at all.
> > 
> > 
> Great - that's why I asked the first question. :) 
BTW, I'm thinking about moving the predecessors/successors definition from MachineSSAContext.h to MachineBasicBlocks.h since they could be useful in general for code sharing between IR and MIR. WDYT?


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