[PATCH] D95962: [CSSPGO] Introducing dangling pseudo probes.

[Hongtao Yu via Phabricator via llvm-commits]

hoy added inline comments.


================
Comment at: llvm/lib/CodeGen/PseudoProbeInserter.cpp:110
+          if (MI.isPseudoProbe())
+            MI.addPseudoProbeAttribute(PseudoProbeAttributes::Dangling);
+        }
----------------
wmi wrote:
> hoy wrote:
> > wmi wrote:
> > > It set all the pseudo probes in MBB to dangling. For DirectCall/IndirectCall types of pseudo probe, they are used to represent inline stack. Do they need to be set to dangling?
> > DirectCalls/IndirectCalls are real call instructions and can be sampled correctly. If there are calls in the block, other types of probes will not be considered dangling.
> If the call is inlined, will the DirectCall be left in the block? 
If the call is inlined, the direct call is gone. And the inline stack will be attached to inlined probes in form of `!dbg`. If the inlined probes end up in a block with no other real instructions, they will be tagged dangling.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D95962/new/

https://reviews.llvm.org/D95962